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A&A365,258–265(2001)

DOI:10.1051/0004-6361:20000330 c ESO2001Astronomy &

Send o?print requests to:K.A.Berrington for a few medium-to-high energies.However,resonance structure is not normally included in these DW calcula-tions,and we show in the present paper that this can have a signi?cant e?ect on the calculated rates for excited transitions.Since Bhatia and Doschek give a good review of the earlier data,we con?ne ourselves in this paper to comparisons with them.

R-matrix calculations include the IRON project work of Pelan&Berrington(1995)on the ground-state?ne-structure transition in Cl-like ions.R-matrix methods in-clude resonances and channel coupling e?ects,and typi-cally more target states are included in the model atom than just the required initial and?nal states,in order to obtain the e?ect of resonance structures converging to higher levels.Pelan and Berrington included the lowest 14LS terms(i.e.all3s23p5,3s3p6and3s23p43d terms), and used an algebraic transformation to intermediate cou-pling(Saraph1978).Mohan et al.(1994)also reported a similar R-matrix calculation,however their calculation ap-peared to omit some resonance contributions and this was discussed more fully by Pelan and Berrington.

The present calculation is part of an international col-laboration known as the IRON Project(Hummer et al. 1993),and extends the R-matrix calculation of Pelan& Berrington(1995)to tabulate data for Fe x from the lowest three levels to the lowest31levels.180target

J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.259

1234567893s 23p 5

3s 3p 6

3s 23p 43d

3s 3p 53d 3s 2

3p 3

3d

2

Fig.1.The model atom:calculated energies (Ryds)of the 180levels from the 75terms included for Fe x

levels were actually included in the present R-matrix calculation,arising from 3s 23p 5,3s3p 6,3s 23p 43d,3s3p 53d and 3s 23p 33d 2con?gurations,as shown in Fig.1.A full Breit-Pauli R-matrix (BPRM)treatment was adopted be-cause term mixing among the 3s 23p 43d levels was consid-ered too big for the algebraic transformation to be valid.This 180-level BPRM calculation is the biggest so far on this ion:the collision calculation required the setting up and diagonalizing of Hamiltonian matrices of order 6164,with 1104coupled channels.

2.The calculation

The basic atomic theory,the approximations and the com-puter codes employed in the IRON Project are described

by Hummer et al.(1993).The target wavefunctions were constructed from 1s,2s,2p,3s and 3p orbitals as given by Clementi &Roetti (1974),together with a 3d orbital opti-mised on the energy of the third 2P o state (i.e.3s3p 53d),and a 4f correlation orbital optimised on the ground state.The optimizations were carried out using Hibbert’s (1975)variational program CIV3.The radial parts of the Slater-type orbitals are

3d(r )=141.9677864exp(?8.0582535r )r 3

+58.2199125exp(?4.3181676r )r 3

4f(r )=183.85325exp(?5.175)r 4.

All con?gurations were included with a minimum num-ber of electrons in each shell of 1s 22s 22p 63s 03p 2and with a maximum of three electrons in the 3d shell and one electron in 4f.This correlation was necessary in order to converge the oscillator strength for the 3s 23p 5–3s3p 6tran-sitions.Two complementary R-matrix calculations were carried out,as now described.

A 180-level BPRM calculation was used for the reso-nance energy region (up to 9.95Ryd),with a maximum of 1104channels in each partial wave.In order for this calculation to be computational feasable,the number of continuum terms was the minimum required to span this energy range:only ?ve per channel,resulting in collisional Hamiltonian matrices of maximum order 6164.The pur-pose of this calculation was to obtain accurate collision strengths in the low-energy resonance region,and since resonances are important only for low partial waves the expansion was truncated at J =6.

A 31-level BPRM calculation was used to top-up both the energy and the partial-wave expansion,in order to calculate converged collision strengths to a high enough energy for collision rates to be obtained over a realistic temperature range.The 31-level calculation had only 158channels,so 30continuum terms per channel could be in-cluded and the partial-waves calculated up to J =56,enabling converged collision strengths to be calculated for the transitions 3s 23p 5–3s3p 6,3s 23p 5–3s 23p 43d and 3s3p 6–3s 23p 43d (i.e.up to the lowest 31levels),and the energy range extended from 9.95to 600Ryd.

Table 1lists the energies of the lowest 31levels calcu-lated from the wavefunction used in the 181-level BPRM calculation,and compares with NIST reference data.Table 2compares the oscillator strengths obtained using the 181-level BPRM wavefunction with those of Bhatia &Doshek (1995).The oscillator strengths from the two calculations are qualitatively similar but not in very good agreement.However,our results are much closer to a re-cent experiment by Tr¨a bert (1996)for the lifetime and branching ratio of the 3s3p 62S e 1/2level (Table 3).

3.Results

We calculated collision strengths ?for ?ne-structure transitions 3s 23p 5–3s3p 6,3s 23p 5–3s 23p 43d and 3s3p 6–3s 23p 43d.In Table 4we show a limited comparison with earlier work,the DW calculation of Bhatia &Doschek (1995),at energies above all thresholds.(Note that they also give data at 9Ryd,and make a comparison with Mason (1975)at 5.5Ry,but we cannot meaningfully compare at these low energies because of resonances,see Fig.1.)Generally the agreement is reasonably good for ex-citations to level 4and above (3s 23p 43d levels),but rather poorer for the 3s 23p 5–3s3p 6doublet,the latter may be ex-plained by the di?erence in calculated oscillator strength between the two calculations,as summarised in Table 3.

260J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI. Table1.The lowest31energy levels(Ryd)for Fe x.For refer-

ence,level32(3s3p53d)is calculated at6.284Ryd.180levels

were actually included in the calculation(see Fig.1).“Expt”

is reference data from Sugar&Corliss(1985)

i

1

3s23p52P o1/2.1346.1429 3

3p43d4D e5/2 3.581 3.542 5

3p43d4D e3/2 3.591 3.554 7

3p43d4F e9/2 3.863 3.806 9

3p43d4F e7/2 3.906 3.853 11

3p43d4F e3/2 3.947 3.903 13

3p43d4P e1/2 4.014 3.962 15

3p43d4P e3/2 4.057

17

3p43d2F e7/2 4.081 4.017 19

3p43d2G e9/2 4.172 4.108 21

3p43d2F e5/2 4.195 4.126 23

3p43d2F e7/2 4.495 4.429 25

3p43d2D e5/2 4.774

27

3p43d2P e3/2 5.255 5.141 29

3p43d2D e5/2 5.351 5.221 311–31/20.07160.1027 2.854E9 1–45/20.71E-4 2.08E-4 3.504E6 1–63/2 2.06E-4 2.02E-4 5.281E6 1–71/29.14E-5 5.59E-5 2.926E6 1–91/2 2.68E-38.12E-4 4.954E7 1–115/2 1.24E-3 1.49E-3 3.031E7 1–123/219.7E-39.03E-3 2.783E8 1–133/2 5.65E-5 2.10E-3 6.651E7 1–141/2 2.25E-3 3.56E-3 2.325E8 1–153/29.56E-3 4.85E-3 1.557E8 1–163/228.2E-4 4.17E-4 1.397E7 1–175/2 6.40E-3 4.64E-3 1.017E8 1–195/215.9E-3 3.67E-38.114E7 1–225/211.1E-4 6.82E-4 1.579E7 1–235/2 3.66E-3 4.60E-3 1.206E8 1–253/20.01310.0100 4.441E8 1–265/20.58E-3 2.45E-37.356E7 1–271/2 1.940 1.312 1.338E11 1–283/2 3.788 2.817 1.542E11 1–291/20.18630.3693 4.260E10 1–305/2 6.462 5.128 1.941E11 1–313/20.2830.1710 1.013E10 2–31/20.03650.0513 1.285E9 2–63/231.9E-6 2.93E-67.094E4 2–71/213.6E-57.75E-5 3.757E6 2–91/272.0E-3 3.62E-3 2.055E8 2–123/27.51E-3 3.96E-3 1.137E8 2–133/2 4.16E-4 3.95E-4 1.169E7 2–141/2 6.77E-47.17E-4 4.382E7 2–153/28.56E-3 3.31E-39.929E7 2–163/215.9E-5 6.84E-5 2.149E6 2–253/211.7E-37.62E-3 3.193E8 2–271/20.21150.4553 4.403E10 2–283/20.24020.1052 5.468E9 2–291/2 1.833 1.091 1.196E11 2–313/2 4.004 3.213 1.810E11

J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.261 Table3.Predictions and measurement(Tr¨a bert1996)on the

line doublet3s23p52P o3/2,1/2–3s3p62S e1/2for Fe x.BD=cal-

culated from Bhatia&Doshek(1995);Present=calculated

from the same wavefunction as used in the present181-level

BPRM collision calculation

BD Present Measured

18.027.036.045.0

.356.363.361.361

BD

2–3

.226.239.252.262

.044.028.020.015

BD

2–4

.012.0079.0056.0042

.0020.0013.0010.0008

BD

1–5

.0593.0383.0265.0193

from the3s3p53d and higher states having negligible ef-fect on transitions from the ground state(Figs.2,3). However,Fig.4show signi?cant resonance structure up to6Ryd above threshold for excitation out of the3s3p6 initial state,and this justi?es the inclusion of the3s3p53d and higher levels in the180-level BPRM calculation in order to obtain accurate data for these transitions.

Collision strengths are computed for the required?ne-structure transitions over a su?ciently wide and?ne energy mesh in order to be able to integrate over a Maxwellian distribution to obtain the e?ective collision strengthΥ,from which the excitation and de-excitation rate coe?cients can easily be obtained(Hummer et al. 1993).Our energy mesh was determined by increasing the number of points until the integration converged:re-sulting in an energy spacing of0.001–0.002Ryd in the

1

2

3

4

5

0.1110

1-3

1

2

3

4

5

0.1110

2-3

Fig.2.Collision strength for3s23p52P o3/2,1/2–3s3p62S e1/2(1–3and2–3)in Fe x,as a function of electron energy(Ryds) relative to threshold:—,?from the present180-level BPRM calculation;----,the resulting thermal average(Υ)plotted against kT in Ryds;.....,Υfrom Mohan et al.(1994); +++,?from Bhatia&Doschek(1995)

resonance regions,a total of7460energy points.The range of temperatures chosen was±0.8dex of the tempera-ture of maximum ionic abundance given by Shull&Van Steenberg(1982),and our?nal results are tabulated in Table6.

Our e?ective collision strengthsΥare also plotted in Figs.2–4as a function of kT Rydbergs,alongside the collision strength?:the?gures illustrate that the en-hancement ofΥdue to low-energy resonances extends to surprisingly large temperatures(~106K).Typical en-hancements are factors of two or three for transitions from the ground state(Figs.2–3)and up to an order of mag-nitude for the optically forbidden transitions out of the excited3s3p6level(Fig.4).

For comparison we also plot the DW?from Bhatia& Doshek(1995)and the early R-matrix calculation ofΥof Mohan et al.(1994),showing that although our present results agree well with these at higher energies(see also Table4),these other calculations appear to underestimate or ignore the resonance contribution at low temperatures.

To see the e?ect of the resonance enhancement more clearly,we recalculate in Table5the level populations given by Bhatia&Doschek(1995)for electron density

262J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.

00.4

0.8

1.20.1110

1-4

0.4

0.8

1.2

0.1110

1-5

Fig.3.Collision strength for 3s 23p 52P o 3/2–3s 23p 43d 4D e

5/2,7/2(1–4and 1–5)in Fe x ,as a function of electron energy relative to threshold:notation as in Fig.2Table 5.E?ect of resonances on the derived level popula-tions for Fe x .“BD”is from Table IV A of Bhatia &Doschek (1995)for electron density 1010cm ?3and 106K.“Present”substitutes our rates from Tables 2&6for those of BD

i BD Present 17.23E-01 6.19E-01

18

1.97E-02

1.55E-02

3 1.86E-09 1.39E-09

20

1.31E-02

1.28E-02

5 2.92E-02 4.10E-02

22

5.67E-08

4.48E-08

7 2.30E-08 4.43E-08

24

4.81E-03

3.88E-03

9 1.14E-09 1.66E-09

26

3.81E-08

7.29E-09

11 4.11E-08 3.09E-08

28

1.65E-10

3.25E-12

13 1.72E-09 6.33E-09

30

2.23E-10

2.08E-10

15

2.30E-09

2.16E-09

00.1

0.2

0.3

0.4

0.1110

3-4

0.1

0.2

0.3

0.4

0.1110

3-5

Fig.4.Collision strength for 3s3p 62S e 1/2–3s 23p 43d 4D e

5/2,7/2(3–4and 3–5)in Fe x ,as a function of electron energy relative to threshold:notation as in Fig.2

1010cm ?3and 106K,with no proton excitation or black-body radiative excitation.We use all our radiative and col-lisonal rates from Tables 2and 6(i.e.for transitions involv-ing levels 1,2and 3),and complete the dataset up to level 31using Bhatia and Doschek’s data:the rate equations are then solved as in their Eq.(3)for the level populations.Our resonance-enhanced Υfor 1–2(2P 3/2?1/2),which we published in an earlier IP paper (Pelan &Berrington 1995),gives some redistribution of population between level 1and 2.But the total 2P ground population drops 7%when the Υfrom the ground state to higher levels also includes resonances as in the present work,and the pop-ulation of 4F 9/2and 4F 7/2(levels 8and 10in Table 5)doubles.

Thus,we conclude that it is not safe to calculate rates from earlier tabulations of the collision strength without taking into account resonance enhancement.We believe that,by including resonance structure associated with 180levels,we have included the most signi?cant resonance e?ects on transitions to the 31lowest levels.

Acknowledgements.This work was done with the support of a PPARC grant GR/K97608.We would like to thank Drs.P.Young and H.Mason for providing the level populations code.

J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.263 Table6.E?ective collision strengths for Fe x?ne structure transitions as a function of log T(Kelvin).The level indexing(i,i′) is de?ned in Table1.(The1–2data is from Pelan&Berrington1995)

5.4 5.6 5.8

6.0 6.2 6.4 6.6 6.8

7.0

2.97 2.69 2.27 1.79 1.350.990.730.540.40

1–3

0.17420.14960.12620.10450.08490.06740.05220.03940.0291

1–5

0.09930.08560.07220.05970.04840.03840.02980.02260.0168

1–7

0.17020.14800.12520.10360.08390.06640.05140.03900.0291

1–9

0.12810.10970.09130.07440.05950.04690.03680.02910.0234

1–11

0.11320.10010.08630.07290.06060.05000.04110.03400.0286

1–13

0.09440.08140.06820.05730.04800.03920.03110.02410.0185

1–15

0.05430.04690.03940.03290.02830.02550.02400.02320.0228

1–17

0.13510.12060.10540.09070.07850.06990.06480.06250.0621

1–19

0.16270.14380.12570.11000.09740.08820.08230.07930.0787

1–21

0.11010.09330.07680.06220.05000.04030.03300.02770.0241

1–23

0.12880.10960.09430.08220.07280.06610.06220.06080.0614

1–25

0.05940.05260.04730.04350.04160.04150.04240.04370.0450

1–27

3.856 3.870 3.898 3.934 3.966 3.992

4.018 4.053 4.101

1–29

6.805 6.883 6.963

7.0327.0837.1247.1717.2367.323

1–31

0.35080.31110.27620.24810.22740.21310.20390.19850.1958

2–4

0.05390.04440.03580.02840.02220.01700.01270.00930.0067

2–6

0.03210.02830.02440.02060.01700.01370.01080.00820.0061

2–8

0.03120.02820.02490.02160.01830.01500.01180.00900.0067

2–10

0.05390.04610.03850.03140.02510.01960.01510.01140.0085

2–12

0.04680.03990.03290.02710.02280.02000.01840.01730.0166

2–14

0.03080.02700.02320.01940.01560.01220.00930.00700.0051

2–16

264J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.

Table6.continued

5.4 5.6 5.8

6.0 6.2 6.4 6.6 6.8

7.0

0.04710.03990.03290.02660.02120.01660.01280.00960.0070

2–18

0.07570.06770.05920.05030.04240.03620.03170.02840.0260

2–20

0.11180.09790.08520.07450.06610.06000.05610.05420.0539

2–22

0.06420.05440.04580.03920.03480.03280.03250.03340.0352

2–24

0.03810.03430.03040.02610.02150.01680.01250.00900.0062

2–26

0.66410.65960.66100.67140.69110.71690.74460.77140.7961

2–28

1.520 1.530 1.540 1.548 1.551 1.550 1.549 1.553 1.564

2–30

4.289 4.335 4.386 4.431 4.462 4.481 4.500 4.533 4.583

3–4

0.07490.06210.04860.03610.02590.01800.01230.00830.0055

3–6

0.03370.02960.02440.01880.01370.00950.00650.00430.0028

3–8

0.14180.12540.10360.07950.05750.03970.02660.01750.0113

3–10

0.04000.03200.02430.01760.01230.00840.00570.00380.0026

3–12

0.05190.04260.03320.02450.01740.01190.00800.00530.0034

3–14

0.06550.05680.04710.03670.02700.01910.01320.00910.0063

3–16

0.08580.07390.05990.04630.03470.02570.01930.01480.0118

3–18

0.09560.08170.06590.05060.03830.02960.02400.02060.0186

3–20

0.07420.05990.04630.03430.02450.01710.01170.00800.0055

3–22

0.04850.04090.03250.02450.01770.01230.00840.00560.0037

3–24

0.04150.03760.03280.02820.02410.02080.01840.01660.0154

3–26

0.27720.27100.23280.18190.13310.09300.06320.04220.0280

3–28

0.11790.10420.08390.06290.04490.03090.02080.01380.0091

3–30

0.11990.09600.07360.05450.03960.02850.02050.01490.0110

J.C.Pelan and K.A.Berrington:Atomic data from the IRON project.XL VI.265

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Fe基体中稀土元素Ce与Pb的相互作用

Fe基体中稀土元素Ce与Pb的相互作用 通过熔炼实验研究了在Fe基体中Ce与Pb的相互作用,EPMA分析和金属的化学键理论表明,Ce对Pb在Fe基体中的分布有控制作用,并可生成Ce-Pb 高熔点金属间化合物CePb,改善杂质元素Pb对钢性能的危害。采用Miedema 模型计算,从热力学上证明了实验分析结果。 标签: 铈;铅;相互作用 随着钢材需求量的不断加大,以废钢为主要原料的短流程炼钢被普遍看好。但在废钢的循环使用过程中,不可避免地将铅等低熔点金属带入到炼钢炉中。由于这些金属的氧化位比铁低,在常规的炼钢工艺中不能有效去除,且易在晶界富集,恶化钢的质量,使钢材发生表面裂纹、热处理回火脆性,以及高温持久强度和抗应力腐蚀强度明显下降等问题。因此,对钢中低熔点金属元素含量的控制及去除问题成为新的研究热点。 稀土元素几乎是唯一能与钢中Pb、Sn等有害元素化合的元素,这是因为稀土元素因电子结构特殊而具有极强的化学活性。本文通过熔炼实验,采用EPMA 分析和金属的化学键理论研究Fe基体中铈与铅的相互作用,为降低Pb对钢的危害提供依据。 1 实验材料与方法 1.1 实验材料 实验材料有低杂质、低合金元素的工业纯铁,铈和铅粒,其化学成分及含量分别见表1,表2和表3。 1.2 实验方法 实验在ZG-001型真空感应熔炼炉上进行。用细砂纸打磨工业纯铁试样,去掉表层氧化皮,装入刚玉坩埚后放在炉腔的石墨坩埚内。密封装置抽真空,当真 空度≤1.0×102Pa时通电加热,同时通入氩气作为保护气体。当工业纯铁试样 全部熔融后,使用旋转合金料斗把铈和铅通过送料口加入熔池中,同时减小氩气的流量,以防流通的氩气带走过多的铅蒸气。熔炼2分钟后断电,试样先随炉冷却,表面稍有凝固后将刚玉坩埚和试样放入事先准备好的盐浴中进行淬冷直至完全冷却。整个实验过程中,温度控制在≤1923K。 将熔炼试样切割成15mm×15mm×15mm左右的正方体,粗磨、细磨、抛光成金相试样,经电子探针(EPMA)和热力学计算,分析试样中不同组织的微区

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金刚石工具胎体中铁(Fe)元素的作用 (1)优点铁是极廉价的元素,在金刚石工具中的用量日渐增多,铁用在金刚石工具中有如下优点: 1)价格低廉; 2)铁与济南市有较好的润湿性,接触角为50°,优于钴和镍; 3)液相时铁与金刚石的附着功为3.4×10-7J/cm2,也优于钴和镍; 4)可以形成多种碳化物,如渗碳体型(Fe3C)和ε型碳化物(Fe2C),有硼参与可形成Fe23(CB)6和Fe3(CB),有W、Mo参与时,形成M6C型碳化物(Fe3W3)C和(Fe3Mo3)C; 5)与骨架材料的相容性很好,液相时与WC的接触角接近于0,对TiC的接触角也很低; 6)Fe具有比Cu、Ni、Co低的线胀系数,其值为11.7×10-6/℃,更接近金刚石的线胀系数,对防止冷却裂纹的出现起一定的作用; 7)烧结时铁对金刚石的轻度刻蚀并不损失金刚石的强度,反而会提高金刚石在胎体中的把持力; 8)对于铁基合金的性能是否能接近或达到钴基合金的性能。 (2)铁在金刚石工具中有如下不足; 1)铁基胎体的变形性大于钴基胎体; 2)铁基胎体的耐磨性高于钴基胎体; 3)铁基胎体中的低熔点金属容易发生流失; 4)铁基胎体的工具不够锋利。

(3)为了正确认识铁在金刚石工具中的作用,作如下几点说明: 高温下铁对金刚石的蚀刻虑远比镍、钴都高,但是实验表明,1000℃以下烧结,金刚石只被轻度蚀刻,并不影响金刚石的强度;金刚石表面被蚀刻的碳并不以石墨形态分布在金刚石表面,而是扩散到金刚石表面的含铁金属膜中,按一定的规律分布。 使铁(钢)在高速状态下与金刚石对磨,金刚石会被眼中磨蚀加工。利用这一特性,可以加工天然钻石。 铁基金刚石工具不锋利的原因是铁比钴耐磨,比钴变形大。 铁基结合剂金属不锋利的原因是铁比钴耐磨,比钴变形大。 铁基结合剂工具烧结流失是由于铁与铜基合金中的低熔点金属的溶解度过低造成的,适量加一些互溶性好的元素即可减少流失

Fe及其化合物知识点

Fe及其化合物的性质 ⑴Fe在周期表中的位置 位于第4周期第Ⅷ族,是过渡元素的代表。它是一种变价元素,通常显示+2价、+3价,其化合物和其水溶液往往带有颜色。 ⑵ Fe与O 2 反应,随着外界条件和两者量的相对多少不同,生成的产物不同。 3Fe + 2O 2 (纯) Fe 3 O 4 (黑色、有磁性) 2Fe (过量) + O 2 2FeO(黑色,该反应在炼钢过程中发生) 4Fe + 3O 2 2Fe 2 O 3 (红棕色) 生成Fe 3O 4 的反应还有:3Fe+4H 2 O(g) Fe 3 O 4 +4H 2 ⑶铁锈的成分及形成 钢铁发生电化腐蚀时,Fe 参与电极反应的产物为Fe2+,后与OH—反应生成 Fe(OH) 2;因其不稳定,又转变成Fe(OH) 3 失去部分水变成Fe 2 O 3 ·n H2O。(在常温 下,铁和水不反应。但在水和空气里的氧气、二氧化碳的共同作用下,铁很容易生锈而被腐蚀。) ⑷铁与酸的反应: 铁与盐酸、稀硫酸的反应:Fe + 2H+ == Fe2+ + H 2 O(反应后溶液呈浅绿色) 铁与过量稀硝酸的反应: Fe + 4H+ + NO 3- == Fe3+ + NO↑+ 5H 2 O(反应后溶 液呈棕黄色) Fe +4HNO 3 (稀) =Fe(NO 3 ) 3 +NO↑+2H 2 O 铁粉过量: 3Fe +8HNO 3(稀) =3Fe(NO 3 ) 2 +2NO↑+4H 2 O 铁与浓硫酸的反应:常温下,Fe在浓硫酸中被钝化,即由于浓硫酸的强氧化性,使Fe的表面生成一层致密的氧化物薄膜,阻止了内部的金属继续跟浓硫酸反应。 金属钠与金属铁的性质比较 性质相同点不同点 物理性质都是银白色的金属, 都能导电、导热。 密度:ρ(Fe)>ρ(Na) 硬度:Fe>Na 熔沸点:Fe>Na 化学性质都能跟氧气、水等反应钠更易与氧气、与水等反应⑸铁的氧化物 氧化物FeO(碱性氧化物)Fe 2O 3 (碱性氧化物)Fe 3 O 4 颜色状态黑色粉末红棕色粉末黑色晶体溶解性不溶于水 磁性无无有 与非氧化性酸反应FeO + 2HCl == FeCl 2 + H 2 O Fe 2 O 3 + 6HCl == 2FeCl 3 + 3H 2 O Fe 3 O 4 + 8HCl == 2FeCl 3 + FeCl 2 + 4H 2 O 点燃 高温 570℃~1 400℃ 高温

与Fe有关的方程式

铁元素化学方程式总结 1. 3 Fe + 3O 4 2. 2 Fe + 3 3. Fe + S 4. 3 Fe + Fe 3O 4 + 4 H 2 5. Fe + 4 HNO 3(稀)Fe(NO 3)3 + NO ↑+ 2 H 2O 6. Fe + 2 Fe(NO 3)3 3 Fe(NO 3)2 7. 3 Fe (足量)+ (稀) 3 Fe(NO 3)2 + 2 NO ↑+ 4 H 2O 8. Fe + 6 HNO 3(浓) 3)3 + 3 NO 2↑+ 3 H 2O 9. 2 Fe + 6 H 2SO 4Fe 2(SO 4)3 + 3 SO 2↑+ 6 H 2O 10. Fe + H 2SO 4(稀) FeSO 4 + H 2↑ 11. 2 Fe(OH)3 + 3 H 2O 12. 6 FeO + O 23O 4 13. Fe 2O 3 + 2 Fe + 3 CO 2 工业炼铁主要的化学方程式 炼铁的主要原料:铁矿石,焦炭,空气,石灰石 14. CaO + SiO 2 3 15. Fe 2O 3 + 3 H 2 Fe + 3 H 2O 16. Fe 3O 4 + 4 H 3 Fe + 4 H 2O 17. FeO + 4 HNO 3(浓)Fe(NO 3)3 + NO 2↑+ 2 H 2O 18. Fe 3O 4 + 8 HCl 2 FeCl 3 + FeCl 2 + 4 H 2O 19. Fe + 2 FeCl 3 3 FeCl 2 20. Fe + Fe 2(SO 4)3 3 FeSO 4 21. 2 FeCl 2 + Cl 2 2 FeCl 3 22. 6 FeBr 2 + 3 Cl 2(少量) 2 FeCl 3 + 4 FeBr 3 23. 2 FeBr 3 + 3 Cl 2 2 FeCl 3 + 3 Br 2 24. 2 FeBr 2 + 3 Cl 2(过量) 2 FeCl 3 + 2 Br 2 25. 12 FeCl 2 + 3 O 2 2 Fe 2O 3 + 8 FeCl 3 26. 2 FeCl 3 + Cu 2 FeCl 2 + CuCl 2 腐蚀铜版

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长这些相的析出时间。但是,碳化物M6c可以溶解氮,因此,氮可以促使m6c的析出。延长退火时间,还可促进m2n(z相)和m6(cn)型复杂氮化物的形成。氮含量对Fe-Cr-Ni三元系中δ铁素体含量的影响在图1-9中给出,可见与碳的影响相似。 此外,氮还对双相不锈钢中的相比例发生影响,如图1-10所示。随氮含量的增加,奥氏体含量增加。这表明,通过改变氮含量可以有效地改变双相不锈钢中相的比例。

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