压力容器用钢在应变强化过程中的宏观性能与显微结构研究
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摘要
本课题作为十一五国家科技支撑项目2006BAK02B02子专题的一部分,设计了两种方法来考察塑性变形对材料性能和组织结构的影响。试验方法包括:用来考察塑性变形对材料宏观机械性能影响的预应变试验;用来分析研究塑性变形过程对材料微观组织结构特别是晶体学结构影响的准原位拉伸EBSD试验。
本文研究结果表明:在施加变形量小于5%的预应变情况下,Q235钢和16MnR钢两种材料的宏观综合机械性能与未施加预应变的原材料钢板相比变化不大,强度有所增强,韧性等指标稍有削减,但仍在国家标准规定值范围内。各个应变点的取向图对比表明,小于5%塑性应变状态下的材料的晶粒取向并没有发生明显的变化。表面形貌方面,不同状态材料出现滑移现象所对应的应变量不同:热轧态Q235在2.5%应变,退火态Q235钢在1.5%应变,热轧态16MnR钢在5%应变,退火态的16MnR钢在2.5%应变,出现滑移线。研究了两种材料不同状态的不同应变的取向差、晶界等的统计值,确定了其规律性及其特征点。材料的晶界和取向差变化趋势在特征应变点处均发生了改变。Q235钢的特征应变点是1.0%,16MnR钢的特征应变点是1.8%。
预应变大于5%后:表面桔皮效应明显;屈强比增大,冲击吸收功降低,韧性降低;有些晶粒经过晶体转动,取向发生了变化,而大多数晶粒的取向变化不明显,只是在晶粒内部形成了亚晶等亚结构。
本文选取7个特征晶粒,对其取向及其在应变变化过程中的取向转动和泰勒因子值变化情况进行了研究。从无应变到了屈服点0.2%应变,6个晶粒转动了较大的角度,而从0.2%应变到1.0%应变的转动量则平均较上一阶段减小了46.4%。而此应变特征点过后,转动量随后又增大,并且此后一直保持转动量的增大趋势,直至缩颈阶段。1.0%应变到1.5%应变,及2.6%应变到5%应变阶段,泰勒因子的变化不大,也就是说此时塑性变形所要克服的变形功变化不大,此时晶粒有一稳定过程。
通过晶体取向图精确确定各晶粒的取向后,为所选取晶粒的每个可能的滑移系计算schmid因子值,根据schmid定律,判断了滑移系的启动及其在变形过程中的变化情况。
As a part of project (No.2006BAK02B02) funded by National Eleventh-five-year Science and Technology Surporting Plan, this study designed two methods to investigate the effect of plastic deformation on performances and structures of Pressure Vessel Steels Q235 and 16MnR. One method is prestrain experimentation which is used to examine the effect of plastic deformation on the mechanical behaviours of these two materials, and the other one is quasi in situ tensile EBSD experiment which is to reseach the effect of plastic deformation on material microstructure, espacially crystal structure.
There was no significant change between the original material and the prestrained one at their mechanical performance when prestain were smaller than 5%. The strength is inhanced due to the strain strengthing effect. Meanwhile, the thoughness is still between the range of the national standard though it decreases a little. It is indicated that the orientations of the grains don’t have obvious change when strain is smaller than 5%. The strain which can lead to slip in different materials are distinct, it is 2.5% for rolled Q235, 1.5% for anealed Q235, 5% for rolled 16MnR, and 2.5% for anealed 16MnR respectively. The statistical disciplines of the grain boundries and misorientation of the two materials were studied. Both materials have their own regularities and characteristic strain points. The characteristic strain point of Q235 is 1.0%, and the one of 16MnR is 1.8%.
When the prestrain is bigger than 5%, the peel effect of the deformed matterial became distinct. And the yield ratios increased, impact toughnesses decrease. Some grains rotated, most grains didn’t change their orientations but formed some subgrains inside.
Seven grains were chosen to research their rotation and Taylor factor’s change during the deformation process. Six grains rotated large angles during the process from no strain to 0.2% strain. And the rotating angle decreased 46.4% averagely from 0.2% strain to 1.0% strain. When the strain was bigger than 1.0%, the rotating angle of each grain increased continuously, untill the strain became very big, even the necking stage. There had not significant change from 1.0% strain to 1.5% strain, and from 2.6% strain to 5% strain. It notes that the deformation work that the materials need to overcome change a little during the two period.
The expected slip systems were calculated from the orientations of the crystallites obtained by OIM maps. The starting and changing of slip system during deformation process were studied according to the schmid law.
本文研究结果表明:在施加变形量小于5%的预应变情况下,Q235钢和16MnR钢两种材料的宏观综合机械性能与未施加预应变的原材料钢板相比变化不大,强度有所增强,韧性等指标稍有削减,但仍在国家标准规定值范围内。各个应变点的取向图对比表明,小于5%塑性应变状态下的材料的晶粒取向并没有发生明显的变化。表面形貌方面,不同状态材料出现滑移现象所对应的应变量不同:热轧态Q235在2.5%应变,退火态Q235钢在1.5%应变,热轧态16MnR钢在5%应变,退火态的16MnR钢在2.5%应变,出现滑移线。研究了两种材料不同状态的不同应变的取向差、晶界等的统计值,确定了其规律性及其特征点。材料的晶界和取向差变化趋势在特征应变点处均发生了改变。Q235钢的特征应变点是1.0%,16MnR钢的特征应变点是1.8%。
预应变大于5%后:表面桔皮效应明显;屈强比增大,冲击吸收功降低,韧性降低;有些晶粒经过晶体转动,取向发生了变化,而大多数晶粒的取向变化不明显,只是在晶粒内部形成了亚晶等亚结构。
本文选取7个特征晶粒,对其取向及其在应变变化过程中的取向转动和泰勒因子值变化情况进行了研究。从无应变到了屈服点0.2%应变,6个晶粒转动了较大的角度,而从0.2%应变到1.0%应变的转动量则平均较上一阶段减小了46.4%。而此应变特征点过后,转动量随后又增大,并且此后一直保持转动量的增大趋势,直至缩颈阶段。1.0%应变到1.5%应变,及2.6%应变到5%应变阶段,泰勒因子的变化不大,也就是说此时塑性变形所要克服的变形功变化不大,此时晶粒有一稳定过程。
通过晶体取向图精确确定各晶粒的取向后,为所选取晶粒的每个可能的滑移系计算schmid因子值,根据schmid定律,判断了滑移系的启动及其在变形过程中的变化情况。
As a part of project (No.2006BAK02B02) funded by National Eleventh-five-year Science and Technology Surporting Plan, this study designed two methods to investigate the effect of plastic deformation on performances and structures of Pressure Vessel Steels Q235 and 16MnR. One method is prestrain experimentation which is used to examine the effect of plastic deformation on the mechanical behaviours of these two materials, and the other one is quasi in situ tensile EBSD experiment which is to reseach the effect of plastic deformation on material microstructure, espacially crystal structure.
There was no significant change between the original material and the prestrained one at their mechanical performance when prestain were smaller than 5%. The strength is inhanced due to the strain strengthing effect. Meanwhile, the thoughness is still between the range of the national standard though it decreases a little. It is indicated that the orientations of the grains don’t have obvious change when strain is smaller than 5%. The strain which can lead to slip in different materials are distinct, it is 2.5% for rolled Q235, 1.5% for anealed Q235, 5% for rolled 16MnR, and 2.5% for anealed 16MnR respectively. The statistical disciplines of the grain boundries and misorientation of the two materials were studied. Both materials have their own regularities and characteristic strain points. The characteristic strain point of Q235 is 1.0%, and the one of 16MnR is 1.8%.
When the prestrain is bigger than 5%, the peel effect of the deformed matterial became distinct. And the yield ratios increased, impact toughnesses decrease. Some grains rotated, most grains didn’t change their orientations but formed some subgrains inside.
Seven grains were chosen to research their rotation and Taylor factor’s change during the deformation process. Six grains rotated large angles during the process from no strain to 0.2% strain. And the rotating angle decreased 46.4% averagely from 0.2% strain to 1.0% strain. When the strain was bigger than 1.0%, the rotating angle of each grain increased continuously, untill the strain became very big, even the necking stage. There had not significant change from 1.0% strain to 1.5% strain, and from 2.6% strain to 5% strain. It notes that the deformation work that the materials need to overcome change a little during the two period.
The expected slip systems were calculated from the orientations of the crystallites obtained by OIM maps. The starting and changing of slip system during deformation process were studied according to the schmid law.
引文
1李建国.压力容器设计的力学基础及其标准应用.北京.机械工业出版社,2005:211-212
2陈学东,杨铁成,艾志斌等.基于风险的检测(RBI)在实践中若干问题讨论.压力容器, 2005, 22 ( 7) :36-44
3余亚屏.压力容器安全系数的选择.压力容器, 1985,(01):25-27
4吴宗之,任彦斌,牛和平等.基于本质安全理论的安全管理体系研究.中国安全科学学报, 2007, 17 (7) : 54-58
5邓阳春,陈钢,杨笑峰等.确定压力容器安全系数原则.中国安全科学学报, 2008, 18(6): 84-88
6黄嘉琥,王为国,寿比南等.各国压力容器用材确定许用应力方法的比较.压力容器,2008,25(4):38-42
7 Martin JB. Plasticity: Fundamental and General Results. Cambridge, MA: MIT Press, 1975, 168-178
8匡震邦,黄筑平,郑颖人.固体本构理论中的某些问题,现代力学和科技进步.北京:清华大学出版社,1998,卷1:350-355
9于洋,王尔德,胡连喜,张宝友,于杰.形变强化对93W-4.9Ni-2.1Fe合金组织及性能的影响.材料科学与工艺, 2005,13(04):442-446
10 C.L.Witt man,M.A.Meyers,H.-R.Pak. Observation of an adiabatic shear band in AISI 4340 steel by high-voltage transmission electron microscopy. Metallurgical Transactions A, 1990,21(2) :707~716.
11 LIU Q, HANSEN N. Effect of main orientation on deformation structure in cold rolled aluminum .Acta Mater.1998, 46(16):5815-5838.
12 KASHIHARA K, TAGAMI M, structure and crystal orientation at deformation bands in [110] aluminum single crystal. 1996. 37: 564-571.
13 Smith, F.A., Jr. Watson, H.E. Metallurgical Transactions A (Physical Metallurgy and Materials Science), v 3, n 8, Aug. 1972, p 2065-73
14 R. M'Saoubi and L. Ryde, Application of the EBSD technique for the characterisation of deformation zones in metal cutting, Materials Science and Engineering: A, 2005, 405:339-349
15 J.F.C. Lins, H.R.Z. Sandim, H.-J. Kestenbach, D. Raabe and K.S. Vecchio, A microstructural investigation of adiabatic shear bands in an interstitial free steel, Materials Science and Engineering: A, 2007 457: 205-218
16 H.R.Z. Sandim and D. Raabe, EBSD study of grain subdivision of a Goss grain in coarse-grained cold-rolled niobium, Scripta Materialia, 2005, 53: 207-212
17 B.Eghbali, EBSD study on the formation of fine ferrite grains in carbon steel during warm deformation . Materials Letters, 2007, 61: 4006-4010
18 Roumen Petrov, Leo Kestens, Anna Wasilkowska, Microstructure and texture of a lightly deformed TRIP-assisted steel characterized by means of the EBSD technique. Materials Science and Engineering, 2007, 447: 285-597
19 Dorothe Dorner, Yoshitaka Adachi and Kaneaki Tsuzaki, Periodic crystal lattice rotation in microband groups in a bcc metal [J]. Scripta Materialia, 2007, 57: 775–778
20张宝红,张星,王强等,塑性变形对铸态AZ31镁合金组织和性能的影响.材料工程, 2005,(05):46-49
21宗影影,薛克敏,单德彬等,塑性变形对BT20钛合金焊缝组织和力学性能的影响.锻压技术, 2005,(02):59-63
22安静,王经涛,郭成,陈金德.低碳钢等径弯曲通道变形数值模拟及组织分析.西安交通大学学报, 2004,(03): 82-86
23宓一川,陈家光.XRD与EBSD在钢板织构研究中的应用.宝钢技术,1998, (5):16～20
24黄晓旭,蔡大勇,刘庆等.背散射电子衍射与透射电镜在单晶铝形变组织研究中的应用.电子显微学报,2002, (l21)4:449～454
25徐祖耀,黄本立,鄢国强.中国材料工程大典.第26卷,材料表征与检测技术.化工出版社,2005:994-996
26 A. J. Wilkinson and P. B. Hirsch. Electron Diffraction Based Techniques in Scanning Electron Microscopy of Bulk Materials. Micron. 1997,28(4):279~308
27 M. N. Alam, M. Blackman and D. W. Pashley. High angle Kikuchi Patterns. Prc. Royal Society of London. 1954:A221~224
28 Garmestani H,HarrisK.orientaion determinnatuion by EBSP in an environmental scanning electronmicroscope.SeriptaMaterial,1999,41(1):47一53
29 J. R. Michael. J. A. Eades. Use of reciprocal Lattice Layer Spacing in Electron Backscatter Diffraction Pattern Analysis. Ultramicroscopy. 2000,8:67
30 Y. Ji, D. Luo, X. D. Wang, Z. G. Li, Y. H. Sun, Z. J. Lu, B. Zong, Y. Xia, G. H. Zhang, L. B. Balk and X. X. Liu. Evaluation of Microstructure and Stress of Cu Damascene Intertconnects using SPM. NI?, YUGOSLAVIA:MIEL.2002,781~783
31 UbhiHS,BowenAW.Analysis and representation of electron backscattered diffraction textuer data-examples from heat treated Al-Li alloy sheet. MaterialsScieneenadTeehnolog,1996,12:880-885
32 Dingley D J,Baba-Kishi K Z and RnadleV. Atlas of Backscattering Kikuchi Diffraction Patterns. Inst.Of Phys. Publishing,1995:448-496
33 F. J. Humphreys. Characterisation of Fine-scale Microstructures by Electron Backscatter Diffraction(EBSD). Scripta Materialia. 2004,51:771~776
34 N. C. Krieger Lassen. The Relative Precision of Crystals Orientations Measured Electron Backscattering Patterns. J. Microscopy. 1996,181:72~81
35 T. C. Isabell, V. P. Dravid. Resolution and Sensitivity of Electron Backscattered Diffrection in a Cold Field Emission Gun SEM. Ultramicroscopy. 1997,67:59~68
36 F. J. Humphrey and I. Brough. High Resolution Electron Backscatter Diffraction with a Field Emission Gun Scanning Electron Microscopy. J. Microscopy. 1999,195:6~9
37 H.R.Z. Sandim and D. Raabe, EBSD study of grain subdivision of a Goss grain in coarse-grained cold-rolled niobium, Scripta Materialia, 2005, 53: 207-212
38 Lisa M. Dougherty, Ellen K. Cerreta, The impact of peak shock stress on the microstructure and shear behavior of 1018 steel, Acta Materialia, 2007, 55:6356-6364
39 A. Oudin, P.D. Hodgson and M.R. Barnett, EBSD analysis of a Ti-IF steel subjected to hot torsion in the ferritic region, Materials Science and Engineering: A, In Press, Corrected Proof, Available online 28 September 2007
40 A.A. Zaldívar-Cadena and A. Flores-Valdés, Prediction and identification of calcium-rich phases in Al–Si alloys by electron backscatter diffraction EBSD/SEM, Materials Characterization, 2007,58:834-841
41 Keshavarz Z, Barnett M R. EBSD analysis of deformation modes in Mg-3Al-1Zn Scripta Materialia. 2006, 55(10): 915-918
42杨平.电子背散射衍射技术及其应用.冶金工业出版社,2007:52-56
43 F.Bridier, P.Villechaise, J.mendez, Analysis of the different slip systems actitived by tension in aα/βtitanium alloy in relation with local crystallographic orientation. Acta Materialia 53(2005):555-567
44 Jun-Hyun Han, Kwang-Koo Jee, Kyu Hwan Oh. Orientation rotation behavior during in situ tensile deformation of polycrystalline 1050 aluminum alloy. International Journal of Mechanical Sciences 45(2003):1613-1623
2陈学东,杨铁成,艾志斌等.基于风险的检测(RBI)在实践中若干问题讨论.压力容器, 2005, 22 ( 7) :36-44
3余亚屏.压力容器安全系数的选择.压力容器, 1985,(01):25-27
4吴宗之,任彦斌,牛和平等.基于本质安全理论的安全管理体系研究.中国安全科学学报, 2007, 17 (7) : 54-58
5邓阳春,陈钢,杨笑峰等.确定压力容器安全系数原则.中国安全科学学报, 2008, 18(6): 84-88
6黄嘉琥,王为国,寿比南等.各国压力容器用材确定许用应力方法的比较.压力容器,2008,25(4):38-42
7 Martin JB. Plasticity: Fundamental and General Results. Cambridge, MA: MIT Press, 1975, 168-178
8匡震邦,黄筑平,郑颖人.固体本构理论中的某些问题,现代力学和科技进步.北京:清华大学出版社,1998,卷1:350-355
9于洋,王尔德,胡连喜,张宝友,于杰.形变强化对93W-4.9Ni-2.1Fe合金组织及性能的影响.材料科学与工艺, 2005,13(04):442-446
10 C.L.Witt man,M.A.Meyers,H.-R.Pak. Observation of an adiabatic shear band in AISI 4340 steel by high-voltage transmission electron microscopy. Metallurgical Transactions A, 1990,21(2) :707~716.
11 LIU Q, HANSEN N. Effect of main orientation on deformation structure in cold rolled aluminum .Acta Mater.1998, 46(16):5815-5838.
12 KASHIHARA K, TAGAMI M, structure and crystal orientation at deformation bands in [110] aluminum single crystal. 1996. 37: 564-571.
13 Smith, F.A., Jr. Watson, H.E. Metallurgical Transactions A (Physical Metallurgy and Materials Science), v 3, n 8, Aug. 1972, p 2065-73
14 R. M'Saoubi and L. Ryde, Application of the EBSD technique for the characterisation of deformation zones in metal cutting, Materials Science and Engineering: A, 2005, 405:339-349
15 J.F.C. Lins, H.R.Z. Sandim, H.-J. Kestenbach, D. Raabe and K.S. Vecchio, A microstructural investigation of adiabatic shear bands in an interstitial free steel, Materials Science and Engineering: A, 2007 457: 205-218
16 H.R.Z. Sandim and D. Raabe, EBSD study of grain subdivision of a Goss grain in coarse-grained cold-rolled niobium, Scripta Materialia, 2005, 53: 207-212
17 B.Eghbali, EBSD study on the formation of fine ferrite grains in carbon steel during warm deformation . Materials Letters, 2007, 61: 4006-4010
18 Roumen Petrov, Leo Kestens, Anna Wasilkowska, Microstructure and texture of a lightly deformed TRIP-assisted steel characterized by means of the EBSD technique. Materials Science and Engineering, 2007, 447: 285-597
19 Dorothe Dorner, Yoshitaka Adachi and Kaneaki Tsuzaki, Periodic crystal lattice rotation in microband groups in a bcc metal [J]. Scripta Materialia, 2007, 57: 775–778
20张宝红,张星,王强等,塑性变形对铸态AZ31镁合金组织和性能的影响.材料工程, 2005,(05):46-49
21宗影影,薛克敏,单德彬等,塑性变形对BT20钛合金焊缝组织和力学性能的影响.锻压技术, 2005,(02):59-63
22安静,王经涛,郭成,陈金德.低碳钢等径弯曲通道变形数值模拟及组织分析.西安交通大学学报, 2004,(03): 82-86
23宓一川,陈家光.XRD与EBSD在钢板织构研究中的应用.宝钢技术,1998, (5):16～20
24黄晓旭,蔡大勇,刘庆等.背散射电子衍射与透射电镜在单晶铝形变组织研究中的应用.电子显微学报,2002, (l21)4:449～454
25徐祖耀,黄本立,鄢国强.中国材料工程大典.第26卷,材料表征与检测技术.化工出版社,2005:994-996
26 A. J. Wilkinson and P. B. Hirsch. Electron Diffraction Based Techniques in Scanning Electron Microscopy of Bulk Materials. Micron. 1997,28(4):279~308
27 M. N. Alam, M. Blackman and D. W. Pashley. High angle Kikuchi Patterns. Prc. Royal Society of London. 1954:A221~224
28 Garmestani H,HarrisK.orientaion determinnatuion by EBSP in an environmental scanning electronmicroscope.SeriptaMaterial,1999,41(1):47一53
29 J. R. Michael. J. A. Eades. Use of reciprocal Lattice Layer Spacing in Electron Backscatter Diffraction Pattern Analysis. Ultramicroscopy. 2000,8:67
30 Y. Ji, D. Luo, X. D. Wang, Z. G. Li, Y. H. Sun, Z. J. Lu, B. Zong, Y. Xia, G. H. Zhang, L. B. Balk and X. X. Liu. Evaluation of Microstructure and Stress of Cu Damascene Intertconnects using SPM. NI?, YUGOSLAVIA:MIEL.2002,781~783
31 UbhiHS,BowenAW.Analysis and representation of electron backscattered diffraction textuer data-examples from heat treated Al-Li alloy sheet. MaterialsScieneenadTeehnolog,1996,12:880-885
32 Dingley D J,Baba-Kishi K Z and RnadleV. Atlas of Backscattering Kikuchi Diffraction Patterns. Inst.Of Phys. Publishing,1995:448-496
33 F. J. Humphreys. Characterisation of Fine-scale Microstructures by Electron Backscatter Diffraction(EBSD). Scripta Materialia. 2004,51:771~776
34 N. C. Krieger Lassen. The Relative Precision of Crystals Orientations Measured Electron Backscattering Patterns. J. Microscopy. 1996,181:72~81
35 T. C. Isabell, V. P. Dravid. Resolution and Sensitivity of Electron Backscattered Diffrection in a Cold Field Emission Gun SEM. Ultramicroscopy. 1997,67:59~68
36 F. J. Humphrey and I. Brough. High Resolution Electron Backscatter Diffraction with a Field Emission Gun Scanning Electron Microscopy. J. Microscopy. 1999,195:6~9
37 H.R.Z. Sandim and D. Raabe, EBSD study of grain subdivision of a Goss grain in coarse-grained cold-rolled niobium, Scripta Materialia, 2005, 53: 207-212
38 Lisa M. Dougherty, Ellen K. Cerreta, The impact of peak shock stress on the microstructure and shear behavior of 1018 steel, Acta Materialia, 2007, 55:6356-6364
39 A. Oudin, P.D. Hodgson and M.R. Barnett, EBSD analysis of a Ti-IF steel subjected to hot torsion in the ferritic region, Materials Science and Engineering: A, In Press, Corrected Proof, Available online 28 September 2007
40 A.A. Zaldívar-Cadena and A. Flores-Valdés, Prediction and identification of calcium-rich phases in Al–Si alloys by electron backscatter diffraction EBSD/SEM, Materials Characterization, 2007,58:834-841
41 Keshavarz Z, Barnett M R. EBSD analysis of deformation modes in Mg-3Al-1Zn Scripta Materialia. 2006, 55(10): 915-918
42杨平.电子背散射衍射技术及其应用.冶金工业出版社,2007:52-56
43 F.Bridier, P.Villechaise, J.mendez, Analysis of the different slip systems actitived by tension in aα/βtitanium alloy in relation with local crystallographic orientation. Acta Materialia 53(2005):555-567
44 Jun-Hyun Han, Kwang-Koo Jee, Kyu Hwan Oh. Orientation rotation behavior during in situ tensile deformation of polycrystalline 1050 aluminum alloy. International Journal of Mechanical Sciences 45(2003):1613-1623
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