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ASTM E23

ASTM E23
ASTM E23

Designation:E23?16An American National Standard Standard Test Methods for

Notched Bar Impact Testing of Metallic Materials1

This standard is issued under the?xed designation E23;the number immediately following the designation indicates the year of original

adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript

epsilon(′)indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the U.S.Department of Defense.

1.Scope*

1.1These test methods describe notched-bar impact testing of metallic materials by the Charpy(simple-beam)test and the Izod(cantilever-beam)test.They give the requirements for: test specimens,test procedures,test reports,test machines(see Annex A1)verifying Charpy impact machines(see Annex A2), optional test specimen con?gurations(see Annex A3),desig-nation of test specimen orientation(see Terminology E1823), and determining the percent of shear fracture on the surface of broken impact specimens(see Annex A4).In addition,infor-mation is provided on the signi?cance of notched-bar impact testing(see Appendix X1),and methods of measuring the center of strike(see Appendix X2).

1.2These test methods do not address the problems associ-ated with impact testing at temperatures below–196°C(77K).

1.3The values stated in SI units are to be regarded as standard.No other units of measurement are included in this standard.

1.3.1Exception—Section8and Annex A4provide inch-pound units for information only.

1.4This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Speci?c precau-tionary statements are given in Section5.

2.Referenced Documents

2.1ASTM Standards:2

B925Practices for Production and Preparation of Powder Metallurgy(PM)Test Specimens

E177Practice for Use of the Terms Precision and Bias in ASTM Test Methods

E691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

E1823Terminology Relating to Fatigue and Fracture Testing E2298Test Method for Instrumented Impact Testing of Metallic Materials

3.Summary of Test Method

3.1The essential features of an impact test are:a suitable specimen(specimens of several different types are recognized), a set of anvils,and specimen supports on which the test specimen is placed to receive the blow of the moving mass,a moving mass that has sufficient energy to break the specimen placed in its path,and a device for measuring the energy absorbed by the broken specimen.

4.Signi?cance and Use

4.1These test methods of impact testing relate speci?cally to the behavior of metal when subjected to a single application of a force resulting in multi-axial stresses associated with a notch,coupled with high rates of loading and in some cases with high or low temperatures.For some materials and temperatures the results of impact tests on notched specimens, when correlated with service experience,have been found to predict the likelihood of brittle fracture accurately.Further information on signi?cance appears in Appendix X1.

5.Precautions in Operation of Machine

5.1Safety precautions should be taken to protect personnel from the swinging pendulum,?ying broken specimens,and hazards associated with specimen warming and cooling media.

6.Apparatus

6.1General Requirements:

6.1.1The testing machine shall be a pendulum type of rigid construction.

6.1.2The testing machine shall be designed and built to conform with the requirements given in Annex A1.

6.2Inspection and Veri?cation:

6.2.1Inspection procedures to verify impact machines di-rectly are provided in A2.2and A2.3.The items listed in A2.2 must be inspected annually.

1These test methods are under the jurisdiction of ASTM Committee E28on

Mechanical Testing and are the direct responsibility of Subcommittee E28.07on

Impact Testing.

Current edition approved Jan.1,2016.Published May2016.Originally approved

https://www.wendangku.net/doc/ba14679533.html,st previous edition approved2012as E23–12c.DOI:10.1520/E0023-

16.

2For referenced ASTM standards,visit the ASTM website,https://www.wendangku.net/doc/ba14679533.html,,or

contact ASTM Customer Service at service@https://www.wendangku.net/doc/ba14679533.html,.For Annual Book of ASTM

Standards volume information,refer to the standard’s Document Summary page on

the ASTM website.

*A Summary of Changes section appears at the end of this standard Copyright?ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959.United States

6.2.2The procedures to verify Charpy machines indirectly,using veri?cation specimens,are given in A2.4.Charpy impact machines must be veri?ed directly and indirectly annually.

7.Test Specimens

7.1Con?guration and Orientation:

7.1.1Specimens shall be taken from the material as speci-?ed by the applicable speci?cation.

7.1.2The type of specimen chosen depends largely upon the characteristics of the material to be tested.A given specimen may not be equally satisfactory for soft nonferrous metals and hardened steels;therefore,many types of specimens are recognized.In general,sharper and deeper notches are required to distinguish differences in very ductile materials or when using low testing velocities.

7.1.3The specimens shown in Figs.1and 2are those most widely used and most generally satisfactory.They are particu-larly suitable for ferrous metals,excepting cast iron.3The Charpy specimen designations are V-notch and U-notch.

N OTE 1—Keyhole notch specimen is similar to U-notch,except the notch width is 1.6mm or less.

7.1.4The specimens commonly found suitable for powder metallurgy materials are shown in Figs.3and 4.Powder metallurgy impact test specimens shall be produced following the procedure in Practices B925.The impact test results of these materials are affected by specimen orientation.Therefore,unless otherwise speci?ed,the position of the specimen in the machine shall be such that the pendulum will strike a surface that is parallel to the compacting direction.For powder metallurgy materials the impact test results are reported as unnotched absorbed impact energy.

7.1.5Sub-size and supplementary specimen recommenda-tions are given in Annex A3.

7.2Specimen Machining:

7.2.1When heat-treated materials are being evaluated,the specimen shall be ?nish machined,including notching,after the ?nal heat treatment,unless it can be demonstrated that the impact properties of specimens machined before heat treatment are identical to those machined after heat treatment.

7.2.2Notches shall be smoothly machined but polishing has proven generally unnecessary.However,since variations in notch dimensions will seriously affect the results of the tests,adhering to the tolerances given in Fig.1is necessary (Appen-dix X1.2illustrates the effects from varying notch dimensions on V-notch specimens).

3

Report of Subcommittee XV on Impact Testing of Committee A-3on Cast Iron,Proceedings,ASTM,V ol 33Part 1,

1933.

ID Number

Description

Dimension

Tolerance

1Length of specimen 55mm +0/-2.5mm 2Centering of notch ±1mm 3Notch length to edge 90°±2°4Adjacent sides angle 90°±0.17°

5Width 10mm ±0.075mm 6Thickness

10mm ±0.075mm 7V Ligament length,Type V 8mm ±0.025mm 7U Ligament length,Type U 5mm ±0.075mm 8V Radius of notch,Type V 0.25mm ±0.025mm 8U Radius of notch,Type U 1mm ±0.025mm 9Angle of notch

45°

±1°A Surface ?nish requirements 2μm (Ra)#B

Surface ?nish requirements

4μm (Ra)

#

FIG.1Charpy (Simple-Beam)Impact Test Specimens,V-Notch and

U-Notch

N OTE 2—In keyhole specimens,the round hole shall be carefully drilled with a slow feed rate.The slot may be cut by any feasible method,but care must be exercised in cutting the slot to ensure that the surface of the drilled hole opposite the slot is not damaged.

7.2.3Identi?cation marks shall only be placed in the fol-lowing locations on specimens:either of the 10-mm square ends;the side of the specimen that faces up when the specimen is positioned in the anvils (see Note 3);or the side of the specimen opposite the notch.No markings,on any side of the specimen,shall be within 10mm of the center line of the notch.Permanent markers,laser engraving,scribes,electrostatic

pencils,and other reasonable marking methods may be used for identi?cation purposes.However,some marking methods can result in damage to the specimens if not used correctly.For example,excessive heat from electrostatic pencils or deforma-tion to the specimen from stamping can change the mechanical properties of the specimen.Therefore,care must always be taken to avoid damage to the specimen.Stamping and other marking processes that result in deformation of the specimen should only be used on the ends of the specimens,prior to notching.

N OTE 3—Careful consideration should be given before placing identi-?cation marks on the side of the specimen to be placed up when

positioned

ID Number

Description

Dimension

Tolerance

1Length of specimen 75mm +0/-2.5mm 2Notch to top

28mm 3Notch length to edge 90°±2°4Adjacent sides angle 90°±0.17°5Width 10mm ±0.025mm 6Thickness

10mm ±0.025mm 7Ligament length 8mm ±0.025mm 8Radius of notch 0.25mm ±0.025mm

9Angle of notch

45°

±1°A Surface ?nish requirement 2μm (Ra)#B

Surface ?nish requirement

4μm (Ra)

#

FIG.2Izod (Cantilever-Beam)Impact Test

Specimen

Dimensions

mm L-Overall Length

55.0±1.0W-Width 10.00±0.13T-Thickness

10.00±0.13

N OTE 1—Adjacent sides shall be at 90°610min.

FIG.3Unnotched Charpy (Simple Beam)Impact Test Specimen

for Metal Powder Structural

Materials

Dimensions

mm L-Overall Length

75.0±1.5W-Width 10.00±0.13T-Thickness

10.00±0.13

N OTE 1—Adjacent sides shall be at 90°610min.

FIG.4Izod (Cantilever-Beam)Impact Test Specimen for P/M

Structural

Materials

in the anvils.If the test operator is not careful,the specimen may be placed in the machine with the identi?cation marking resting on the specimen supports(that is,facing down).Under these circumstances,the absorbed energy value obtained may be unreliable.

8.Procedure

8.1Preparation of the Apparatus:

8.1.1Perform a routine procedure for checking impact machines at the beginning of each day,each shift,or just prior to testing on a machine used intermittently.It is recommended that the results of these routine checks be kept in a log book for the machine.After the testing machine has been ascertained to comply with Annex A1and Annex A2,carry out the routine check as follows:

8.1.1.1Visually examine the striker and anvils for obvious damage and wear.

8.1.1.2Check the zero position of the machine by using the following procedure:raise the pendulum to the latched position,move the pointer to near the maximum capacity of the range being used,release the pendulum,and read the indicated value.The pointer should indicate zero on machines reading directly in energy.On machines reading in degrees,the reading should correspond to zero on the conversion chart furnished by the machine manufacturer.

N OTE4—On machines that do not compensate for windage and friction losses,the pointer will not indicate zero.In this case,the indicated values, when converted to energy,shall be corrected for frictional losses that are assumed to be proportional to the arc of swing.

8.1.1.3The friction and windage loss shall not exceed0.4% of the scale range being tested and should not change by more than10%of the percent friction and windage loss measure-ments previously recorded on the machine.If the percent friction and windage loss does exceed0.4%or is signi?cantly different from previous measurements,check the indicating mechanism,the latch height,and the bearings for wear and damage.However,if the machine has not been used recently, let the pendulum swing for50to100cycles,and repeat the percent friction and windage test before undertaking repairs to the machine.To ensure that friction and windage losses are within allowable tolerances,use one of the following evalua-tion procedures:

(1)For a machine equipped with an analog scale:

Raise the pendulum to the latched position;

Move the pointer to the maximum scale value being used;

Release the pendulum(without a specimen in the machine);

Allow the pendulum to cycle?ve times(a forward and a backward

swing together count as one cycle);

Prior to the sixth forward swing set the pointer to between5and10

%of the maximum scale value being used;

After the sixth forward swing record the value indicated by the

pointer(convert to energy if necessary);

Divide the energy reading by10;

Divide by the maximum scale value being used,and

Multiply by100to get the percent friction and windage loss.

(2)A machine equipped with a digital display: Determine the percent friction and windage loss per manufac-turer’s procedure.

(3)For machine equipped with both an analog scale and digital display:

Determine the friction and windage loss using the same indicating device used to report absorbed energy(10.2.4and A2.4).

N OTE5—Prior to the2012version,the percent friction and windage was based on11(half)swings and the pointer was not engaged on the?rst swing.Now the pointer is engaged on the?rst swing.The difference is that the friction,windage,and pointer losses associated with the?rst swing are no longer assumed to be zero.On the1st swing the pointer should go to 0.00,so any friction that will be recorded will only show up on the following10(half)swings.

8.2Test Temperature Considerations:

8.2.1The temperature of testing affects the impact proper-ties of most materials.For materials with a body centered cubic structure,a transition in fracture mode occurs over a tempera-ture range that depends on the chemical composition and microstructure of the material.Test temperatures may be chosen to characterize material behavior at?xed values,or over a range of temperatures to characterize the transition region,lower shelf,or upper shelf behavior,or all of these.The choice of test temperature is the responsibility of the user of this test method and will depend on the speci?c application. For tests performed at room temperature,a temperature of 20°C65°C is recommended.

8.2.2The temperature of a specimen can change signi?-cantly during the interval it is removed from the temperature conditioning environment,transferred to the impact machine, and the fracture event is completed(see Note8).When using a heating or cooling medium near its boiling point,use data from the references in Note8or calibration data with thermo-couples to con?rm that the specimen is within the stated temperature tolerances when the striker contacts the specimen. If excessive adiabatic heating is expected,monitor the speci-men temperature near the notch during fracture.

8.2.3Verify temperature-measuring equipment at least ev-ery six months.If liquid-in-glass thermometers are used,an initial veri?cation shall be sufficient,however,the device shall be inspected for problems,such as the separation of liquid,at least twice annually.

8.2.4Hold the specimen at the desired temperature within 61°C(62°F)in the temperature conditioning environment. Any method of heating or cooling or transferring the specimen to the anvils may be used provided the temperature of the specimen immediately prior to fracture is essentially the same as the holding temperature(see Note8).The maximum change in the temperature of the specimen allowed for the interval between the temperature conditioning treatment and impact is not speci?ed here,because it is dependent on the material being tested and the application.The user of nontraditional or lesser used temperature conditioning and transfer methods(or specimen sizes)shall show that the temperature change for the specimen prior to impact is comparable to or less than the temperature change for a standard size specimen of the same material that has been thermally conditioned in a commonly used medium(oil,air,nitrogen,acetone,methanol),and transferred for impact within5s(see Note8).Three tempera-ture conditioning and transfer methods used in the past are: liquid bath thermal conditioning and transfer to the specimen supports with centering tongs;furnace thermal conditioning and robotic transfer to the specimen supports;placement of the specimen on the supports followed by in situ heating and

cooling.

8.2.4.1For liquid bath cooling or heating use a suitable container,which has a grid or another type of specimen positioning ?xture.Cover the specimens,when immersed,with at least 25mm (1in.)of the liquid,and position so that the notch area is not closer than 25mm to the sides or bottom of the container,and no part of the specimen is in contact with the container.Place the device used to measure the temperature of the bath in the center of a group of the specimens.Agitate the bath and hold at the desired temperature within 61°C (62°F).Thermally condition the specimens for at least 5min before testing,unless a shorter thermal conditioning time can be shown to be valid by measurements with thermocouples.Leave the device (tongs,for example)used to handle the specimens in the bath for at least 5min before testing,and return the device to the bath between tests.

8.2.4.2When using a gas medium,position the specimens so that the gas circulates around them and hold the gas at the desired temperature within 61°C (62°F)for at least 30min.Leave the device used to remove the specimen from the medium in the medium except when handling the specimens.

N OTE 6—Temperatures up to +260°C may be obtained with certain oils,but “?ash-point”temperatures must be carefully observed.

N OTE 7—For testing at temperatures down to –196°C (77°K),standard testing procedures have been found to be adequate for most metals.N OTE 8—A study has shown that a specimen heated to 100°C in water can cool 10°C in the 5s allowed for transfer to the specimen supports.4Other studies,using cooling media that are above their boiling points at room temperature have also shown large changes in specimen temperature during the transfer of specimens to the machine anvils.In addition,some materials change temperature dramatically during impact testing at cryogenic temperatures due to adiabatic heating.5

8.3Charpy Test Procedure:

8.3.1The Charpy test procedure may be summarized as follows:the test specimen is thermally conditioned and posi-tioned on the specimen supports against the anvils;the pendu-lum is released without vibration,and the specimen is impacted by the https://www.wendangku.net/doc/ba14679533.html,rmation is obtained from the machine and from the broken specimen.

8.3.2To position a test specimen in the machine,it is recommended that self-centering tongs similar to those shown in Fig.5be used (see A1.10.1).The tongs illustrated in Fig.5are for centering V-notch specimens.If non V-notch specimens are used,modi?cation of the tong design may be necessary.If an end-centering device is used,caution must be taken to ensure that low-energy high-strength specimens will not re-bound off this device into the pendulum and cause erroneously high recorded values.Many such devices are permanent ?xtures of machines,and if the clearance between the end of a specimen in the test position and the centering device is not approximately 13mm,the broken specimens may rebound into the pendulum.

8.3.3To conduct the test,prepare the machine by raising the pendulum to the latched position,set the energy indicator at the maximum scale reading,or initialize the digital display,or

both,position the specimen on the anvils,and release the pendulum.If a liquid bath or gas medium is being used for thermal conditioning,perform the following sequence in less than 5s (for 10×10×55mm specimens,see 8.2.4).Remove the test specimen from its cooling (or heating)medium with centering tongs that have been temperature conditioned with the test specimen,place the specimen in the test position,and release the pendulum smoothly.If a test specimen has been removed from the temperature conditioning bath and it is questionable that the test can be conducted within the 5s time frame,return the specimen to the bath for the time required in 8.2before testing.

8.3.3.1If a fractured impact specimen does not separate into two pieces,report it as unbroken (see 9.2.2for separation instructions).Unbroken specimens with absorbed energies of less than 80%of the machine capacity may be averaged with values from broken specimens.If the individual values are not listed,report the percent of unbroken specimens with the average.If the absorbed energy exceeds 80%of the machine capacity and the specimen passes completely between the anvils,report the value as approximate (see 10.1)and do not average it with other values.If an unbroken specimen does not pass between the machine anvils,(for example,it stops the pendulum),the result shall be reported as exceeding the machine capacity.A specimen shall never be struck more than once.

8.3.3.2If a specimen jams in the machine,disregard the results and check the machine thoroughly for damage or misalignment,which would affect its calibration.

8.3.3.3To prevent recording an erroneous value,caused by jarring the indicator when locking the pendulum in its upright (ready)position,read the value for each test from the indicator prior to locking the pendulum for the next test.

8.4Izod Test Procedure:

8.4.1The Izod test procedure may be summarized as follows:the test specimen is positioned in the specimen-holding ?xture and the pendulum is released without https://www.wendangku.net/doc/ba14679533.html,rmation is obtained from the machine and from the broken specimen.The details are described as follows:

8.4.2Testing at temperatures other than room temperature is difficult because the specimen-holding ?xture for Izod speci-mens is often part of the base of the machine and cannot be readily cooled (or heated).Consequently,Izod testing is not recommended at other than room temperature.

8.4.3Clamp the specimen ?rmly in the support vise so that the centerline of the notch is in the plane of the top of the vise within 0.125mm.Set the energy indicator at the maximum scale reading,and release the pendulum smoothly.Sections 8.3.3.1–8.3.3.3,also apply when testing Izod https://www.wendangku.net/doc/ba14679533.html,rmation Obtainable from Impact Tests

9.1The absorbed energy shall be taken as the difference between the energy in the striking member at the instant of impact with the specimen and the energy remaining after breaking the specimen.This value is determined by the machine’s scale reading which has been corrected for windage and friction losses.

N OTE 9—Alternative means for energy measurement are acceptable

4

Nanstad,R.K.,Swain,R.L.and Berggren,R.G.,“In?uence of Thermal Conditioning Media on Charpy Specimen Test Temperature,”Charpy Impact Test:Factors and Variables,ASTM STP 1072,ASTM,1990,pp.195-210.5

Tobler R.L.Et al.,“Charpy Impact Tests Near Absolute Zero,”Journal of Testing and Evaluation ,V ol 19,1

1992.

provided the accuracy of such methods can be demonstrated.Methods used include optical encoders and strain-gaged strikers.

9.2Lateral expansion measurement methods must take into account the fact that the fracture path seldom bisects the point of maximum expansion on both sides of a specimen.One half of a broken specimen may include the maximum expansion for both sides,one side only,or neither.Therefore,the expansion on each side of each specimen half must be measured relative to the plane de?ned by the undeformed portion on the side of

the specimen,as shown in Fig.6.For example,if A 1is greater than A 2,and A 3is less than A 4,then the lateral expansion is the sum of A 1+A 4.

9.2.1Before making any lateral expansion measurements,it is essential that the two specimen halves are visually examined for burrs that may have formed during impact testing;if the burrs will in?uence the lateral expansion measurements,they must be removed (by rubbing on emery cloth or any other suitable method),making sure that the protrusions to

be

ID Number

Designation Dimension,mm ID Number

Designation Dimension,mm 1

39.93+0–0.051

8B

1.52to 1.650.69to 0.810.36to 0.4827.94±1917.46±1344.5±0.5°10 4.76±142±1119.5±159.5±1127.94±1619.9613 1.588±1719.9614

10 mm specimen width 5 mm specimen width 3 mm specimen width Solder pad length Solder pad extension Solder pad height

rod

Solder pad width

9.5±1

8A

Support (notch side) length

Support (notch side) height

Insert angle Radius on support Support width Notch center Notch center

10 mm specimen width 5 mm specimen width 3 mm specimen width 1.60to 1.700.74to 0.800.45to 0.51

FIG.5Centering Tongs for V-Notch Charpy

Specimens

measured are not rubbed during the removal of the burr.Then,examine each fracture surface to ascertain that the protrusions have not been damaged by contacting an anvil,a machine mounting surface,https://www.wendangku.net/doc/ba14679533.html,teral expansion shall not be measured on a specimen with this type of damage.

9.2.2Lateral expansion measurements shall be reported as follows.An unbroken specimen can be reported as broken if the specimen can be separated by pushing the hinged halves together once and then pulling them apart without further fatiguing the specimen,and the lateral expansion measured for the unbroken specimen (prior to bending)is equal to or greater than that measured for the separated halves.In the case where a specimen cannot be separated into two halves,the lateral expansion can be measured as long as the shear lips can be accessed without interference from the hinged ligament that has been deformed during testing.The specimen should be reported as unbroken.

9.2.3Lateral expansion may be measured easily by using a gage like the one shown in Fig.7(assembly and details shown in Fig.8).Using this type of gage the measurement is made with the following procedure:orient the specimen halves so that the compression sides are facing each other,take one half of the fractured specimen and press it against the anvil and dial gage plunger and record the reading,make a similar measure-ment on the other half (same side)of the fractured specimen and disregard the lower of the two values,do the same for the other side of the fractured specimen,report the sum of the maximum expansions for the 2sides as the lateral expansion for the specimen.

9.3The percentage of shear fracture on the fracture surfaces of impact specimens may be determined using a variety of methods.The approach and the acceptable methods are de?ned in Annex A4.For each method,the user must distinguish between regions formed by stable crack growth mechanisms,and regions formed by unstable crack growth mechanisms.For purposes of this Test Method,the “shear area”consists of those portions of the fracture surface that form by stable crack growth (Fracture Initiation Region,Shear Lips,and Final Fracture Region),as shown in Fig.9.

The percent shear area on the fracture surface of a Charpy impact specimen is typically calculated as the difference between the total fractured area (Fracture Initiation Region,Shear Lips,Unstable Fracture region,and Final Fracture Region)and the area of unstable fracture region,divided by the total fractured area,times 100.The measurement methods described in Annex A4provide estimates for the area of the unstable fracture region (directly or indirectly),but do not consider details of the fracture mode for the unstable region.The unstable fracture region could be 100%cleavage,a mixture of cleavage and ductile-dimple fracture morphologies,a mixture of intergranular and ductile-dimple fracture morphologies,or a mixture of other fracture

morphologies.

FIG.6Halves of Broken Charpy V-Notch Impact Specimen Illus-trating the Measurement of Lateral Expansion,Dimensions A 1,

A 2,A 3,A 4and Original Thickness,Dimension

W

FIG.7Lateral Expansion Gage for Charpy Impact

Specimens

N OTE 10—Carbon steels often exhibit a classic cleavage region that identi?es the unstable fracture region with a well-de?ned area of shiny fracture that is easy to recognize and measure.Other steels,such as quenched and tempered SAE 4340,alloys have a region of unstable fracture that consists of an intimate mixture of cleavage facets and ductile dimples (only apparent at high magni?cations).Some embrittled steels can exhibit partially intergranular fracture,as well.In these cases the area of unstable fracture may not be as easy to identify.

10.Report

10.1Absorbed energy values above 80%of the scale range are inaccurate and shall be reported as approximate.Ideally an impact test would be conducted at a constant impact velocity.In a pendulum-type test,the velocity decreases as the fracture progresses.For specimens that have impact energies approach-ing 80%of the capacity of the pendulum,the velocity of the

pendulum decreases (to about 45%of the initial velocity)during fracture to the point that accurate impact energies are no longer obtained.

10.2For commercial acceptance testing,report the follow-ing information (for each specimen tested):10.2.1Specimen type,

10.2.2Specimen size (if sub-size specimen),10.2.3Test temperature,10.2.4Absorbed energy,and

10.2.5Any other contractual requirements.

10.3For other than commercial acceptance testing the following information is often reported in addition to the information in 10.2

:

ID Num Dimension,mm

ID Num Dimension,mm

112.715 1.592 6.416 6.4388.91717.54171.51815.9547.619 1.7650.8200.57101.6218.3888.922 3.2912.723 6.11044.52419.11112.72566.71243.22619.11388.927

60.3

14

158.8

FIG.8Assembly and Details for Lateral Expansion

Gage

10.3.1Lateral expansion,10.3.2Unbroken specimens,

10.3.3Fracture appearance (%shear,See Note A4.1),10.3.4Specimen orientation,and 10.3.5Specimen location.

N OTE 11—Even when the test temperature is speci?ed as room temperature,report the actual temperature.

11.Precision and Bias

11.1An Interlaboratory study used CVN specimens of low energy and of high energy to ?nd sources of variation in the CVN absorbed energy.Data from 29laboratories were in-cluded with each laboratory testing one set of ?ve specimens of each energy level.Except being limited to only two energy levels (by availability of reference specimens),Practice E691was followed for the design and analysis of the data;the details are given in ASTM Research Report No.RR:E28-1014.6

11.2Precision—The Precision information given below is for the average CVN absorbed energy of ?ve test determina-tions at each laboratory for each material.

Material

Low Energy

High Energy

J J Absorbed Energy

15.996.295%Repeatability Limit 2.48.395%Reproducibility Limits

2.7

9.2

The terms repeatability and reproducibility limit are used as de?ned in Practice E177.The respective standard deviations among test results may be obtained by dividing the above limits by 2.8.

11.3Bias—Bias cannot be de?ned for CVN absorbed en-ergy.The physical simplicity of the pendulum design is complicated by complex energy loss mechanisms within the machine and the specimen.Therefore,there is no absolute standard to which the measured values can be compared.12.Keywords

12.1Charpy test;fracture appearance;impact test;Izod test;notched specimens;pendulum machine

6

Supporting data have been ?led at ASTM International Headquarters and may be obtained by requesting Research Report RR:

E28–1014.

N OTE 1—Measure average dimensions A and B to the nearest 0.5mm.Determine the percent shear fracture using Table A4.1or Table A4.2.

FIG.9Schematic of the Fracture Surface of a Charpy V-Notch Impact Test Specimen Showing the Various Region of

Fracture

ANNEXES

(Mandatory Information)

A1.GENERAL REQUIREMENTS FOR IMPACT MACHINES

A1.1The machine frame shall be equipped with a bubble level or a machined surface suitable for establishing levelness of the axis of pendulum bearings or,alternatively,the levelness of the axis of rotation of the pendulum may be measured directly.The machine shall be level to within3:1000and securely bolted to a concrete?oor not less than150mm thick or,when this is not practical,the machine shall be bolted to a foundation having a mass not less than40times that of the pendulum.The bolts shall be tightened as speci?ed by the machine manufacturer.

A1.2A scale or digital display,graduated in degrees or energy,on which readings can be estimated in increments of 0.25%of the energy range or less shall be furnished for the machine.

A1.2.1The scales and digital displays may be compensated for windage and pendulum friction.The error in the scale reading at any point shall not exceed0.2%of the range or 0.4%of the reading,whichever is larger.(See A2.3.8.)

A1.3The total friction and windage losses of the machine during the swing in the striking direction shall not exceed 0.75%of the scale range capacity,and pendulum energy loss from friction in the indicating mechanism shall not exceed 0.25%of scale range capacity.See A2.3.8for friction and windage loss calculations.

A1.4The position of the pendulum,when hanging freely, shall be such that the striker is within2.5mm from the test specimen.When the indicator has been positioned to read zero energy in a free swing,it shall read within0.2%of the scale range when the striker of the pendulum is held against the test specimen.The plane of swing of the pendulum shall be perpendicular to the transverse axis of the Charpy specimen anvils or Izod vise within3:1000.

A1.5Transverse play of the pendulum at the striker shall not exceed0.75mm under a transverse force of4%of the effective weight of the pendulum applied at the center of strike. Radial play of the pendulum bearings shall not exceed 0.075mm.

A1.6The impact velocity(tangential velocity)of the pen-dulum at the center of strike shall not be less than3nor more than6m/s.

A1.7The height of the center of strike in the latched position,above its free hanging position,shall be within0.4% of the range capacity divided by the supporting force,mea-sured as described in A2.3.5.1.If windage and friction are compensated for by increasing the height of drop,the height of drop may be increased by not more than1%.

A1.8The mechanism for releasing the pendulum from its initial position shall operate freely and permit release of the pendulum without initial impulse,retardation,or side vibra-tion.If the same lever used to release the pendulum is also used to engage the brake,means shall be provided for preventing the brake from being accidentally engaged.

A1.9Specimen clearance is needed to ensure satisfactory results when testing materials of different strengths and com-positions.The test specimen shall exit the machine with a minimum of interference.Pendulums used on Charpy ma-chines are of three basic designs,as shown in Fig.A1.1.

A1.9.1When using a C-type pendulum or a compound pendulum,the broken specimen will not rebound into the pendulum and slow it down if the clearance at the end of the specimen is at least13mm or if the specimen is de?ected out of the machine by some arrangement such as that shown in Fig. A1.1.

A1.9.2When using a U-type pendulum,means shall be provided to prevent the broken specimen from rebounding against the pendulum(see Fig.A1.1).In most U-type pendu-lum machines,steel shrouds should be designed and installed to the following requirements:(a)thickness of approximately 1.5mm,(b)minimum hardness of45HRC,(c)radius of less than1.5mm at the underside corners,and(d)positioned so that the clearance between them and the pendulum overhang(both top and sides)does not exceed1.5mm.

N OTE A1.1—In machines where the opening within the pendulum permits clearance between the ends of a specimen(resting on the specimen supports)and the shrouds,and this clearance is at least13mm, the requirements(a)and(d)need not apply.

A1.10Charpy Apparatus:

A1.10.1Means shall be provided(see Fig.A1.2)to locate and support the test specimen against two anvil blocks in such a position that the center of the notch is located within0.25mm of the midpoint between the anvils(see8.3.2).

A1.10.2The supports and striker shall be of the forms and dimensions shown in Fig.A1.2.Other dimensions of the pendulum and supports should be such as to minimize inter-ference between the pendulum and broken specimens.

A1.10.3The center line of the striker shall advance in the plane that is within0.40mm of the midpoint between the supporting edges of the anvils.The striker shall be perpendicu-lar to the longitudinal axis of the specimen within5:1000.The striker shall be parallel within1:1000to the face of a perfectly square test specimen held against the anvils.

A1.11Izod Apparatus

:

FIG.A1.1Typical Pendulums and Anvils for Charpy Machines,Shown with Modi?cations to Minimize Jamming

N OTE 1—Anvils shall be manufactured with a surface ?nish of 0.1μm (R a )or better on surfaces A and B above the anvil supports when mounted on the machine.

N OTE 2—Striker shall be manufactured with a surface ?nish of 0.1μm (R a )or better along the front radius and along both sides.N OTE 3—All dimensional tolerances shall be 60.05mm unless otherwise speci?ed.

FIG.A1.2Charpy Striker

A1.11.1Means shall be provided (see Fig.A1.3)for clamp-ing the specimen in such a position that the face of the specimen is parallel to the striker within 1:1000.The edges of the clamping surfaces shall be sharp angles of 90°61°with radii less than 0.40mm.The clamping surfaces shall be smooth with a 2μm (R a )?nish or better,and shall clamp the specimen ?rmly at the notch with the clamping force applied in the direction of impact.For rectangular specimens,the clamping

surfaces shall be ?at and parallel within 0.025mm.For cylindrical specimens,the clamping surfaces shall be con-toured to match the specimen and each surface shall contact a minimum of π/2rad (90°)of the specimen circumference.A1.11.2The dimensions of the striker and its position relative to the specimen clamps shall be as shown in Fig.A1.3.

A2.VERIFICATION OF PENDULUM IMPACT MACHINES

A2.1The veri?cation of impact machines has two parts:di-rect veri?cation,which consists of inspecting the machine to ensure that the requirements of this annex and Annex A1are met,and indirect veri?cation,which entails the testing of veri?cation specimens.

A2.1.1Izod machines are veri?ed by direct veri?cation annually.

A2.1.2Charpy machines shall be veri?ed directly and indirectly annually.Data is valid only when produced within 365days following the date of the most recent successful veri?cation test.Charpy machines shall also be veri?ed imme-diately after replacing parts that may affect the measured

energy,after making repairs or adjustments,after they have been moved,or whenever there is reason to doubt the accuracy of the results,without regard to the time interval.These restrictions include cases where parts,which may affect the measured energy,are removed from the machine and then reinstalled without modi?cation (with the exception of when the striker or anvils are removed to permit use of a different striker or set of anvils and then are reinstalled,see A2.1.3).It is not intended that parts not subjected to wear (such as pendulum and scale linearity)are to be directly veri?ed each year unless a problem is evident.Only the items cited in A2.2are required to be inspected annually.Other parts of

the

N OTE 1—All dimensional tolerances shall be 60.05mm unless otherwise speci?ed.N OTE 2—The clamping surfaces of A and B shall be ?at and parallel within 0.025mm.N OTE 3—Surface ?nish on striker and vise shall be 2μm (R a ).

N OTE 4—Striker width must be greater than that of the specimen being tested.

FIG.A1.3Izod (Cantilever-Beam)Impact

Test

machine shall be directly veri?ed at least once,when the machine is new,or when parts are replaced.

A2.1.3Charpy machines do not require immediate indirect veri?cation after removal and replacement of the striker or anvils,or both,that were on the machine when it was veri?ed provided the following safeguards are implemented:(1)an organizational procedure for the change is developed and followed,(2)high-strength low-energy quality control speci-mens(see A2.4.1.1for guidance in breaking energy range for these specimens)are tested prior to removal and immediately after installation of the previously veri?ed striker or anvils,or both within the365day veri?cation period,(3)the results of the before and after tests of the quality control specimens are within1.4J of each other,(4)the results of the comparisons are kept in a log book,and(5)before reattachment,the striker and anvils are visually inspected for wear and dimensionally veri?ed to assure that they meet the required tolerances of Fig. A1.2.The use of certi?ed impact veri?cation specimens is not required and internal quality control specimens are permitted. A2.2Direct Veri?cation of Parts Requiring Annual Inspec-tion:

A2.2.1Inspect the specimen supports,anvils,and striker and replace any of these parts that show signs of wear.A straight edge or radius gage can be used to discern differences between the used and unused portions of these parts to help identify a worn condition(see Note A2.1).

N OTE A2.1—To measure the anvil or striker radii,the recommended procedure is to make a replica(casting)of the region of interest and measure cross sections of the replica.This can be done with the anvils and striker in place on the machine or removed from the machine.Make a dam with cardboard and tape surrounding the region of interest,then pour a low-shrinkage casting compound into the dam(silicon rubber casting compounds work well).Allow the casting to cure,remove the dam,and slice cross sections through the region of interest with a https://www.wendangku.net/doc/ba14679533.html,e these cross sections to make radii measurements on optical comparators or other instruments.

A2.2.2Ensure the bolts that attach the anvils and striker to the machine are tightened to the manufacturer’s speci?cations. A2.2.3Verify that the shrouds,if applicable,are properly installed(see A1.9.2).

A2.2.4The pendulum release mechanism,which releases the pendulum from its initial position,shall comply with A1.8. A2.2.5Check the level of the machine in both directions (see A1.1).

A2.2.6Check that the foundation bolts are tightened to the manufacturer’s speci?cations.

N OTE A2.2—Expansion bolts or fasteners with driven-in inserts shall not be used for foundations.These fasteners will work loose and/or tighten up against the bottom of the machine indicating a false high torque value when the bolts are tightened.

A2.2.7Check the indicator zero and the friction loss of the machine as described in8.1.

A2.3Direct Veri?cation of Parts to be Veri?ed at Least Once:

A2.3.1Charpy anvils and supports or Izod vises shall conform to the dimensions shown in Fig.A1.2or Fig.A1.3.

N OTE A2.3—The impact machine will be inaccurate to the extent that some energy is used in deformation or movement of its component parts or of the machine as a whole;this energy will be registered as used in fracturing the specimen.

A2.3.2The striker shall conform to the dimensions shown in Fig.A1.2or Fig.A1.3.The mounting surfaces must be clean and free of defects that would prevent a good?t.Check that the striker complies with A1.10.3(for Charpy tests)or A1.11.1 (for Izod tests).

A2.3.3The pendulum alignment shall comply with A1.4 and A1.5.If the side play in the pendulum or the radial play in the bearings exceed the speci?ed limits,adjust or replace the bearings,or a combination thereof.

A2.3.4Determine the Center of Strike—For Charpy ma-chines the center of strike of the pendulum is determined using a half-thick specimen(10×5×55mm)in the test position. With the striker in contact with the specimen,a line marked along the top edge of the specimen on the striker will indicate the center of strike.For Izod machines,the center of strike may be considered to be the contact line when the pendulum is brought into contact with a specimen in the normal testing position.

A2.3.5Determine the Potential Energy—The following procedure shall be used when the center of strike of the pendulum is coincident with the radial line from the centerline of the pendulum bearings(herein called the axis of rotation)to the center of gravity(see Appendix X2).If the center of strike is more than1.0mm from this line,suitable corrections in elevation of the center of strike must be made in A2.3.8.1and A2.3.9,so that elevations set or measured correspond to what they would be if the center of strike were on this line.The potential energy of the system is equal to the height from which the pendulum falls,as determined in A2.3.5.2,times the supporting force,as determined in A2.3.5.1.

A2.3.5.1To measure the supporting force,support the pendulum horizontally to within15:1000with two supports, one at the bearings(or center of rotation)and the other at the center of strike on the striker(see Fig.A2.1).Then arrange the support at the striker to react upon some suitable weighing device such as a platform scale or balance,and determine the weight to within0.4%.Take care to minimize friction at either point of support.Make contact with the striker through a round rod crossing the center of strike.The supporting force is the scale reading minus the weights of the supporting rod and any shims that may be used to maintain the pendulum in a horizontal position.

A2.3.5.2Determine the height of pendulum drop for com-pliance with the requirement of A1.7.On Charpy machines determine the height from the top edge of a half-thick(or center of a10×10×55mm)specimen to the elevated position of the center of strike within0.1%.On Izod machines determine the height from a distance22.66mm above the vise to the release position of the center of strike within0.1%.The height may be determined by direct measurement of the elevation of the center of strike or by calculation from the change in angle of the pendulum using the following formulas (see Fig.A2.1):

h5S~12cosβ!

(A2.1)

h 15S ~12cos α!

(A2.2)

where:

h =initial elevation of the striker,m,

S =length of the pendulum distance to the center of strike,

m,

β=angle of fall,

h 1=height of rise,m,and α=angle of rise.

A2.3.6Determine the impact velocity,v ,of the machine,neglecting friction,by means of the following equation:

v 5=2gh

(A2.3)

where:

v =velocity,m/s,

g =acceleration of gravity,9.81m/s 2,and h =initial elevation of the striker,m.

A2.3.7The center of percussion shall be at a point within 1%of the distance from the axis of rotation to the center of strike in the specimen,to ensure that minimum force is transmitted to the point of rotation.Determine the location of the center of percussion as follows:

A2.3.7.1Using a stop watch or some other suitable time-measuring device,capable of measuring time to within 0.2s,swing the pendulum through a total angle not greater than 15°and record the time for 100complete cycles (to and fro).The period of the pendulum then,is the time for 100cycles divided by 100.

A2.3.7.2Determine the center of percussion by means of the following equation:

L 5

gp 24π2

(A2.4)

where:

L =distance from the axis to the center of percussion,m,g =local gravitational acceleration (accuracy of one part in

one thousand),m/s 2,π= 3.1416,and

p =period of a complete swing (to and fro),s.

A2.3.8Determination of the Friction Losses—The energy loss from friction and windage of the pendulum and friction in the recording mechanism,if not corrected,will be included in the energy loss attributed to breaking the specimen and can result in erroneously high measurements of absorbed

energy.

FIG.A2.1Dimensions for

Calculations

For machines recording in degrees,frictional losses are usually not compensated for by the machine manufacturer,whereas in machines recording directly in energy,they are usually com-pensated for by increasing the starting height of the pendulum. Determine energy losses from friction as follows.

A2.3.8.1Without a specimen in the machine,and with the indicator at the maximum energy reading,release the pendu-lum from its starting position and record the energy value indicated.This value should indicate zero energy if frictional losses have been corrected by the manufacturer.Now raise the pendulum slowly until it just contacts the indicator at the value obtained in the free swing.Secure the pendulum at this height and within0.1%determine the vertical distance from the center of strike to the top of a half-width specimen positioned on the specimen rest supports(see A2.3.5).Determine the supporting force as in A2.3.5.1and multiply by this vertical distance.The difference between this value and the initial potential energy is the total energy loss in the pendulum and indicator combined.Without resetting the pointer,repeatedly release the pendulum from its initial position until the pointer shows no further movement.The energy loss determined by the ?nal position of the pointer is that due to the pendulum alone. The frictional loss in the indicator alone is then the difference between the combined indicator and pendulum losses and those due to the pendulum alone.

A2.3.9The indicating mechanism accuracy shall be checked to ensure that it is recording accurately over the entire range(see A1.2.1).Check it at graduation marks corresponding to approximately0,10,20,30,50,and70%of each range. With the striker marked to indicate the center of strike,lift the pendulum and set it in a position where the indicator reads,for example,13J.Secure the pendulum at this height and within 0.1%determine the vertical distance from the center of strike to the top of a half-width specimen positioned on the specimen supports(see A2.3.5).Determine the residual energy by multiplying the height of the center of strike by the supporting force,as described in A2.3.5.1.Increase this value by the total frictional and windage losses for a free swing(see A2.3.8.1) multiplied by the ratio of the angle of swing of the pendulum from the latch to the energy value being evaluated to the angle of swing of the pendulum from the latch to the zero energy reading.Subtract the sum of the residual energy and propor-tional frictional and windage loss from the potential energy at the latched position(see A2.3.5).The indicator shall agree with the energy calculated within the limits of A1.2.1.Make similar calculations at other points of the scale.The indicating mecha-nism shall not overshoot or drop back with the pendulum. Make test swings from various heights to check visually the operation of the pointer over several portions of the scale.

N OTE A2.4—Indicators that indicate in degrees shall be checked using the above procedure.Degree readings from the scale shall be converted to energy readings using the conversion formula or table normally used in testing.In this way the formula or table can also be checked for windage and friction corrections.

A2.4Indirect Veri?cation:

A2.4.1Indirect veri?cation requires the testing of speci-mens with certi?ed energy values to verify the accuracy of Charpy impact machines.

A2.4.1.1Veri?cation specimens with certi?ed energy values are produced at low(13to20J),high(88to136J),and super-high(176to244J)energy levels.To meet the veri?ca-tion requirements,the average value determined for a set of veri?cation specimens at each energy level tested shall corre-spond to the certi?ed values of the veri?cation specimens within1.4J(1.0ft lbf)or5.0%,whichever is greater.

A2.4.1.2The reference values for the veri?cation specimens shall be established on the three reference machines owned, maintained,and operated by NIST in Boulder,CO.

A2.4.2The veri?ed range of a Charpy impact machine is described with reference to the lowest and highest energy specimens tested on the machine.These values are determined from tests on sets of veri?cation specimens at two or more levels of absorbed energy,except in the case where a Charpy machine has a maximum capacity that is too low for two energy levels to be tested.In this case,one level of absorbed energy can be used for indirect veri?cation.

A2.4.3Determine the usable range of the impact testing machine prior to testing veri?cation specimens.The usable range of an impact machine is dependent upon the resolution of the scale or readout device at the low end and the capacity of the machine at the high end.

A2.4.3.1The resolution of the scale or readout device establishes the lower limit of the usable range for the machine. The lower limit is equal to25times the resolution of the scale or readout device at15J.

N OTE A2.5—On analog scales,the resolution is the smallest change in energy that can be discerned on the scale.This is usually1?4to1?5of the difference between2adjacent marks on the scale at the15J energy level.

N OTE A2.6—Digital readouts usually incorporate devices,such as digital encoders,with a?xed discrete angular resolution.The resolution of these types of readout devices is the smallest change in energy that can be consistently measured at15J.The resolution of these types of devices is usually not a change in the last digit shown on the display because resolution is a function of the angular position of the pendulum and changes throughout the swing.For devices which incorporate a veri?ca-tion mode in which a live readout of absorbed energy is available,the pendulum may be moved slowly in the area of15J to observe the smallest change in the readout device(the resolution).

A2.4.3.2The upper limit of the usable range of the machine is equal to80%of the capacity of the machine.

A2.4.4Only veri?cation specimens that are within the usable range of the impact machine shall be tested.To verify the machine over its full usable range,test the lowest and highest energy levels of veri?cation specimens commercially available that are within the machine’s usable range.If the ratio between the highest and lowest certi?ed values tested is greater than four,testing of a third set of intermediate energy speci-mens is required(if the specimens are commercially available).

N OTE A2.7—Use the upper bound of the energy range given for the low, high,and super-high veri?cation specimens(20,136,and244J respec-tively)to determine the highest energy level veri?cation specimens that can be tested.Alternately,use the lower bound of the energy range given for the veri?cation specimens to determine the minimum energy level for testing.

A2.4.4.1If the low energy veri?cation specimens were not tested(only high and super-high were tested),the lower limit

of

the veri?ed range shall be one half the energy of the lowest energy veri?cation set tested.

N OTE A2.8—For example,if the certi?ed value of the high energy specimens tested was 100J,the lower limit would be 50J.

A2.4.4.2If the highest energy veri?cation specimens avail-able for a given Charpy machine capacity were not tested,the

upper value of the veri?ed range shall be 1.5times the certi?ed value of the highest energy specimens tested.

N OTE A2.9—For example,if the machine being tested has a maximum capacity of 325J and only low and high energy veri?cation specimens were tested,the upper bound of the veri?ed range would be 150J (100J ×1.5=150J),assuming that the high energy samples tested had a certi?ed value of 100J.To verify this machine over its full range,low,high,and super-high veri?cation specimens would have to be tested,because

super-high veri?cation specimens can be tested on a machine with a 325J capacity (80%of 325J is 260J,and the certi?ed value of super-high specimens never exceeds 260J).See Table A2.1.

TABLE A2.1Veri?ed Ranges for Various Machine Capacities

and Veri?cation Specimens Tested A

Machine Capacity J Resolution

J

Usable

Range

J Veri?cation Specimens Tested Veri?ed

Range

J Low High Super-high

800.10 2.5to 64X ...... 2.5to 641600.20 5.0to 128X X ... 5.0to 1283250.25 6.25to 260X X X 6.25to 2604000.307.5to 320...X X 50to 3204000.15 3.75to 320X X ... 3.75to 1504000.15 3.75to 320

X X X 3.75to 320

A

In these examples,the high energy veri?cation specimens are assumed to have

a certi?ed value of 100J.

A3.ADDITIONAL IMPACT TEST SPECIMEN CONFIGURATIONS

A3.1Sub-Size Specimen —When the amount of material available does not permit making the standard impact test specimens shown in Figs.1and 2,smaller specimens may be used,but the results obtained on different sizes of specimens cannot be compared directly (X1.3).When Charpy specimens other than the standard are necessary or speci?ed,it is recommended that they be selected from Fig.A3.1.When reporting sub-size specimen dimensions,list the width,thickness,and length (for example,the upper left specimen in Fig.A3.1would

be 10×2.5×55mm).

ID Number

Description

Dimension

Tolerance

1Width,Standard 10.0mm ±0.075mm 1A Width,Half 5.0mm ±0.050mm 1B Width,Third

3.0mm ±0.030mm 2Thickness,Standard 10.0mm ±0.075mm 2A Thickness,Quarter 2.5mm ±0.025mm 2B Thickness,Half

5.0mm ±0.050mm 2C Thickness,Three-Quarters 7.5mm ±0.075mm 2D Thickness,Double

20.0mm ±0.075mm 3Ligament Length,Standard 8.0mm ±0.025mm 3A Ligament Length,Half 4.0mm ±0.025mm 3B

Ligament Length,Third

2.4mm

±0.025

mm

N OTE 1—The circled specimen is the standard V-notch specimen (see Fig.1).

N OTE 2—On sub-size specimens the length,notch angle,notch radius,surface ?nish are constant with V-notch specimens (see Fig.1);width,thickness,and ligament length vary as indicated above.

FIG.A3.1

Sub-Size Charpy (Simple-Beam)V-Notch Impact Test Specimens

A3.2Supplementary Specimens —For economy in prepara-tion of test specimens,special specimens of round or rectan-gular cross section are sometimes used for cantilever beam test.These are shown as Specimens X,Y ,and Z in Figs.A3.2and

A3.3.Specimen Z is sometimes called the Philpot specimen,after the name of the original designer.For hard materials,the machining of the ?at surface struck by the pendulum is sometimes

omitted.

N OTE 1—Permissible variations for type X specimens shall be as follows:

Perpendicularity of notch axis ±2°

Adjacent (90°sides)shall be at Ligament length

±10min ±0.025

mm

N OTE 2—Permissible variations for both specimens shall be as follows:

Cross-section dimensions ±0.025mm Lengthwise dimensions +0,?2.5mm Angle of notch ±1°

Radius of notch

±0.025mm Notch diameter of Type Y specimen

±0.025mm

FIG.A3.2Izod (Cantilever-Beam)Impact Test Specimens,Types X and

Y

Types Y and Z require a different vise from that shown in Fig.A1.3,each half of the vise having a semi-cylindrical recess that closely ?ts the clamped portion of the specimen.As previously

stated,the results cannot be reliably compared with those obtained using specimens of other sizes or shapes.

A4.DETERMINATION OF THE PROPORTION OF SHEAR FRACTURE SURFACE

A4.1These fracture-appearance methods are based on the concept that 100%shear (stable)fracture occurs above the transition-temperature range and brittle unstable fracture oc-curs below the range,as shown by the instrumented Charpy data in Fig.A4.1(see also Test Method E2298).This shear measurement process was developed for carbon steels that undergo a distinct ductile to brittle transition that results in a clearly de?ned region of cleavage fracture (unstable)on the surface of the specimen.Fracture surface interpretation is complicated in materials that exhibit mixed-mode fracture during unstable crack extension.

In the transition-temperature range,fracture is initiated at the root of the notch by ?brous tearing.A short distance from the notch,unstable crack extension occurs (F bf )as the fracture mechanism changes to cleavage,mixed mode,or another low energy fracture mode,which often results in distinct radial markings in the central portion of the specimen (indicative of fast,unstable fracture).After several microseconds the unstable crack extension arrests (F a ).Final fracture occurs at the remaining ligament and at the sides of the specimen in a stable manner.As shear-lips are formed at the sides of the specimen,

the plastic hinge at the remaining ligament ruptures.In the ideal case,a “picture frame”of ?brous “shear”(stable)fracture surrounds a relatively ?at area of unstable fracture.

The ?ve methods used below may be used to determine the percentage of stable fracture on the surface of Charpy V-notch impact specimens.It is recommended that the user qualita-tively characterize the fracture mode of the unstable fracture zone,and provide a description of how the shear measurements were made.The methods are grouped in order of increasing precision.In the case where a specimen does not separate into two halves during the impact test and the fracture occurs without any evidence of unstable crack extension,the percent shear fracture can be considered to be 100%and the specimen should be reported as unbroken.

N OTE A4.1—Round robin data (?ve https://www.wendangku.net/doc/ba14679533.html,panies,1990)estimates of the percent shear for ?ve quenched and tempered 8219steels and four microalloyed 1040steels indicated the following:(1)results using method A4.1.1systematically underestimated the percent shear (compared with method A4.1.4),(2)the error using method A4.1.2was random and,(3)the typical variation in independent measurements using method A4.1.4was on the order of 5to 10%for microalloyed 1040steels.

The ?at shall be parallel to the longitudinal centerline of the specimen and shall be parallel to the bottom of the notch within

2:1000.

TYPE Z

N OTE 1—Permissible variations shall be as follows:

Perpendicularity between notch length and longitudinal centerline ±2°

Cross-section dimensions ±0.025mm Length of specimen +0,?2.5mm Angle of notch ±1°

Radius of notch ±0.025mm Notch depth

±0.025mm

FIG.A3.3Izod (Cantilever-Beam)Impact Test Specimen (Philpot),Type

Z

A4.1.1Measure the length and width of the unstable frac-ture region of the fracture surface,as shown in Fig.9,and determine the percent shear from Table A4.1and Table A4.2depending on the units of measurement.

A4.1.2Compare the appearance of the fracture of the specimen with a fracture appearance chart such as that shown in Fig.A4.2

.

FIG.A4.1Instrumented Charpy impact data showing behavior of steels in the (a)lower shelf,(b)transition,and (c)upper shelf regions.The symbols are de?ned as:(1)F gy ,general yield force,(2)F m ,maximum force,(3)F bf ,force at initiation of unstable crack propagation,and (4)F a ,force at end of unstable crack

propagation (arrest

force).

A4.1.3Magnify the fracture surface and compare it to a precalibrated overlay chart or measure the percent shear fracture by means of a planimeter.

A4.1.4Photograph the fracture surface at a suitable magni-?cation and measure the percent shear fracture by means of a planimeter.

A4.1.5Capture a digital image of the fracture surface and measure the percent shear fracture using image analysis software.

TABLE A4.1Percent Shear for Measurements Made in Millimetres

N OTE 1—100%shear is to be reported when either A or B is zero.

Dimension B,mm

Dimension A,mm

1.0 1.5

2.0 2.5

3.0 3.5

4.0 4.5

5.0 5.5

6.0 6.5

7.07.5

8.08.5

9.09.5101.0999898979696959494939292919190898988881.5989796959493929291908988878685848382812.0989695949291908988868584828180797776752.5979594929189888684838180787775737270693.0969492918987858381797776747270686664623.5969391898785828078767472696765636158564.0959290888582807775727067656260575552504.5949289868380777572696663615855524946445.0949188858178757269666259565350474441375.5939086837976726966625955524845423835316.0928985817774706662595551474440363329256.5928884807672676359555147433935312723197.0918782787469656156524743393430262117127.591868177726762585348443934302520161168.0

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

15

10

5

TABLE A4.2Percent Shear for Measurements Made in Inches

N OTE 1—100%shear is to be reported when either A or B is zero.

Dimension B,in.Dimension A,in.

0.050.100.120.140.160.180.200.220.240.260.280.300.320.340.360.380.400.0598969594949392919090898887868585840.1096929089878584828179777674737169680.1295908886858381797775737169676563610.1494898684828077757371686664625957550.1694878582797774726967646159565351480.1893858380777472686562595654514845420.2092848177747268656158555248454239360.2291827975726865615754504743403633290.2490817773696561575450464238343027230.2690797571676258545046413733292520160.2889777368645955504641373228231814100.30887671666156524742373227231813930.31

88

75

70

65

60

55

50

45

40

35

30

25

20

18

10

5

国外主要无损检测标准(含中英文名称对照)

国外主要无损检测标准(含中英文名称对照)

ASTM A 754/A 754M-1996X射线荧光法测量涂层厚度的试验方法 Test Method for Coating Thickness by X-Ray Fluorescence ASTM B567-1998用β射线背散射法测量涂层厚度的试验方法 Test Method for Measurement of Coating Thickness by the Beta Backscatter Method ASTM B568-1998χ射线光谱仪法测量涂层厚度的试验方法 Test Method for Measurement of Coating Thickness by X-Ray Spectrometry ASTM C637-1998辐射屏蔽混凝土用集料的标准规范 Standard Specification for Aggregates for Radiation-Shielding Concrete ASTM C638-1992辐射屏蔽混凝土集料组分的描述术语 Descriptive Nomenclature of Constituents of Aggregates for Radiation-Shielding Concrete

ASTM C1455-2000用γ射线谱法无损检定仍然有效特殊核材料指南 ASTM D2599-1987X射线光谱法测定汽油含铅量的试验方法(05.02) Test Method for Lead in Gasoline by X-Ray Spectrometry (05.02) ASTM D4294-1998用非色散X射线荧光光谱法测定石油产品中含硫量试验方法 Sulfur in Petroleum Products by Non-Dispersive X-Ray Fluorescence Spectrometry, Method of Test for (05.02) ASTM D4452-1985土壤样品的X射线照相法X-Ray Radiography of Soil Samples ASTM D5059-1998X-射线光谱法测定汽油含铅量的试验方法 Test Method for Lead in Gasoline by X-Ray Spectroscopy (05.03) ASTM D5187-1991X射线衍射法测定煅烧石油焦炭中结晶尺寸(LC)的试验方法 Test Method for Crystallite Size (LC) of Calcined Petroleum Coke by X-Ray Diffraction (05.03)

astme505中文版

A S T M E505中文版-CAL-FENGHAI-(2020YEAR-YICAI)_JINGBIAN

压铸件质量标准 1.范围 1.1 本《气孔和铸件质量要求》标准适用于压铸件。 1.2 所有的线性尺寸单位为英寸 2.定义 砂眼——铸件中由夹带气体引起的表面缺陷。 冷隔——由于金属的凝固速率不同,有时在压铸过程中产生的凝固金属的重叠。 内部缩孔——铸件冷凝期间的一种情况,铸件内部体积收缩而形成空隙但铸件的外形尺寸没有减小。 穿透性缺陷——铸件中有一个闭环孔或通孔,其孔径大于0.005(0.127㎜)但不属于设计部分。 注:本标准中所指的“穿透性缺陷”均参照以上的定义。 3.分类 气孔等级允许的气孔缺陷密度 Ⅰ不允许有气孔缺陷 Ⅱ在φ0.250(φ6.35㎜)观察区域内不大于φ0.020(φ0.508㎜)的气孔最多不超过5个或不大于φ0.040(φ1.016㎜)的气孔不超过1个. Ⅲ在φ0.250(φ6.35㎜)观察区域内不大于φ0.040(φ1.016㎜)的气孔不超过3个,不大于φ0.020(φ0.508㎜)的气孔不超过2个,或不大于φ0.060(φ1.524㎜)的气孔不超过1个. Ⅳ在φ0.250(φ6.35㎜)观察区域内不大于φ0.040(φ1.016㎜)的气孔不超过3个,不大于φ0.020(φ0.508㎜)的气孔不超过2个,或在φ0.500(φ12.7㎜)观察区域内不大于φ0.100(φ2.54㎜)的气孔不超过1个. 4.铸件气孔及铸件质量的一般要求 4.1不加工表面 不允许有可见的内部缩孔和砂眼 若供应商和客户许可,允许有微小的可见的冷隔 若无附加说明,不允许有不完整的零件特征 气孔密度应符合气孔等级Ⅰ 4.2加工表面 不允许有可见的内部缩孔、冷隔和砂眼 不完整的零部件特征是不允许的 穿透性缺陷不应大于零件特征或壁厚的50℅ 2

国外主要无损检测标准(含中英文名称对照)

ASTM A 754/A 754M-1996X射线荧光法测量涂层厚度的试验方法 Test Method for Coating Thickness by X-Ray Fluorescence ASTM B567-1998用β射线背散射法测量涂层厚度的试验方法 Test Method for Measurement of Coating Thickness by the Beta Backscatter Method ASTM B568-1998χ射线光谱仪法测量涂层厚度的试验方法 Test Method for Measurement of Coating Thickness by X-Ray Spectrometry ASTM C637-1998辐射屏蔽混凝土用集料的标准规范 Standard Specification for Aggregates for Radiation-Shielding Concrete ASTM C638-1992辐射屏蔽混凝土集料组分的描述术语 Descriptive Nomenclature of Constituents of Aggregates for Radiation-Shielding Concrete ASTM C1455-2000用γ射线谱法无损检定仍然有效特殊核材料指南 ASTM D2599-1987X射线光谱法测定汽油含铅量的试验方法(05.02) Test Method for Lead in Gasoline by X-Ray Spectrometry (05.02) ASTM D4294-1998用非色散X射线荧光光谱法测定石油产品中含硫量试验方法 Sulfur in Petroleum Products by Non-Dispersive X-Ray Fluorescence Spectrometry, Method of Test for (05.02) ASTM D4452-1985土壤样品的X射线照相法X-Ray Radiography of Soil Samples ASTM D5059-1998X-射线光谱法测定汽油含铅量的试验方法 Test Method for Lead in Gasoline by X-Ray Spectroscopy (05.03) ASTM D5187-1991X射线衍射法测定煅烧石油焦炭中结晶尺寸(LC)的试验方法 Test Method for Crystallite Size (LC) of Calcined Petroleum Coke by X-Ray Diffraction (05.03) ASTM D6247-1998X射线荧光光谱法分析聚烯烃中元素含量的试验方法 Test Method for Analysis of Elemental Content in Polyolefins by X-Ray Fluorescence Spectrometry ASTM E94-2004(2010)射线照相检验标准指南Standard Guide for Radiographic Examination ASTM E142-1996射线照相检测的质量控制方法Method for Controlling Quality of Radiographic Testing ASTM E155-2010铝镁合金铸件射线照相检验标准参考照片 Standard Reference Radiographs for Inspection of Aluminum and Magnesium Castings ASTM E170-1999有关辐射测量和剂量测定的术语 ASTM E181-1998放射性核素探测器的校准和分析的一般方法 General Methods for Detector Calibration and Analysis of Radionuclides ASTM E186-2010厚壁(50.8-114mm)钢铸件标准参考射线照片 Standard Reference Radiographs for Heavy-Walled (2 to 4 1/2-In./50.8 to 114-mm) Steel Castings ASTM E192-2004(2010)e1宇航用熔模钢铸件标准参考射线照片 Standard Reference Radiographs for Investment Steel Castings of Aerospace Applications ASTM E242-2001(2010)某些参数改变时射线照相图象显示的标准参考射线照片 Standard Reference Radiographs for Appearances of Radiographic Images as Certain Parameters Are Changed ASTM E272-2010高强度铜基及镍铜合金铸件的标准参考射线照片 Standard Reference Radiographs for High-Strength Copper-Base and Nickel-Copper Alloy Castings ASTM E280-2010厚壁(114-305mm)铸钢件标准参考射线照片

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