Inelastic recovery of Q&P980 ultra high strength steel with a complicated deformation path

doi:10.16511/j.cnki.qhdxxb.2018.26.038

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Abstract The loading paths used for sheet metal forming affect its elastic-plastic flow behavior. Quenching & partitioning (Q&P) 980 steel was used here as the research object. Two-step tensile tests using different angles relative to the rolling direction were conducted at room temperature to obtain the stress-strain curves for various stress states. The equal volume plasticity work principle was used to determine the experimental yield loci of different equivalent plastic strain (0%, 1%, 4%, 6%). The results show that the initial flow stress is significantly reduced by changing the strain path, especially in the 45° and 90° directions, the flow stress after the transient period various by a fixed amount, and the anisotropy is quite large for larger strains. The test yield loci line is convex and some of the yield loci are asymmetric. As the deformation increases, the yield loci expand outward. Simple loading and cyclic loading were compared to analyze the elasto-plastic behavior and develop unloading string mathematical models. The elastic modulus decreases quickly with increasing strain, then decreases slowly and then becomes constant. For a given plastic strain, the change in the elastic modulus during cyclic loading is greater than when simply loaded.

Keywords ultra high strength steel complex strain path yield loci inelastic recovery

Issue Date: 17 October 2018

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	HAN Fei
	CAO Zhaobing

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HAN Fei,CAO Zhaobing. Inelastic recovery of Q&P980 ultra high strength steel with a complicated deformation path[J]. Journal of Tsinghua University(Science and Technology), 2018, 58(10): 921-928.

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http://jst.tsinghuajournals.com/EN/10.16511/j.cnki.qhdxxb.2018.26.038 OR http://jst.tsinghuajournals.com/EN/Y2018/V58/I10/921

[1] 宋思川, 陈龑, 姜峻岭, 等. QP980钢在车身轻量化开发中的应用[J]. 现代制造工程, 2017(1):51-54. SONG S C, CHEN Y, JIANG J L, et al. Application of QP980 in lightweight development of body in white[J]. Modern Manufacturing Engineering, 2017(1):51-54. (in Chinese)
[2] 吴向东, 万敏, 周贤宾. 汽车薄钢板应力应变曲线及屈服轨迹的研究[J]. 力学学报, 2004, 36(4):507-512. WU X D, WAN M, ZHOU X B. Stress-strain curves and yield loci of auto steel sheet[J]. Acta Mechanica Sinica, 2004, 36(4):507-512. (in Chinese)
[3] TARIGOPULA V, HOPPERSTAD O S, LANGSETH M, et al. Elastic-plastic behaviour of dual-phase,high-strength steel under strain-path changes[J]. European Journal of Mechanics-A/Solids, 2008, 27(5):764-782.
[4] LIAO J, SOUSA J A, LOPES A B, et al. Mechanical, micros-tructural behaviour and modelling of dual phase steels under complex deformation paths[J]. International Journal of Plasticity, 2016, 93:269-290.
[5] YOSHIDA F, UEMORI T, FUJIWARA K. Elastic-plastic behavior of steel sheets under in-plane cyclic tension-compression at large strain[J]. International Journal of Plasticity, 2002, 18(5-6):633-659.
[6] 高付海, 桂良进, 范子杰. 两种新型单拉平板剪切试件的设计与对比[J]. 清华大学学报(自然科学版), 2010, 50(2):299-302. GAO F H, GUI L J, FAN Z J. Design and comparison of two new in-plane shear specimens[J]. Journal of Tsinghua University (Science and Technology), 2010, 50(2):299-302.(in Chinese)
[7] 余海燕, 孙喆. 非比例加载路径下TRIP钢的应变硬化行为[J]. 塑性工程学报, 2012, 19(6):90-94. YU H Y, SUN Z. Strain hardening behavior of TRIP steels under non-proportional loading path[J]. Journal of Plasticity Engineering, 2012, 19(6):90-94. (in Chinese)
[8] 余海燕, 鲍立, 高云凯. 相变诱发塑性钢板的非弹性回复行为及其对回弹的影响[J]. 机械工程学报, 2010, 46(18):46-51. YU H Y, BAO L,GAO Y K. Inelastic recovery behavior of transformation induced plasticity steels and its influence on springback[J]. Journal of Mechanical Engineering, 2010, 46(18):46-50. (in Chinese)
[9] 庄京彪, 刘迪辉, 李光耀. 基于包辛格效应的回弹仿真分析[J]. 机械工程学报, 2013, 49(22):84-90. ZHUANG J B, LIU D H, LI G Y. Analysis of springback simulation based on Bauschinger effect[J]. Journal of Mechanical Engineering, 2013, 49(22):84-90. (in Chinese)
[10] KIM H J, KIM C M, BARLAT F, et al.Nonlinear elastic behaviors of low and high strength steels in unloading and reloading[J]. Materials Science & Engineering A, 2013, 562:161-171.
[11] 孙珊珊. 卸载循环对Q&P980钢微观组织影响的研究[D]. 长春:吉林大学, 2016. SUN S S, Study on the effect of unloading cycle on microstructure of Q&P980 steel[D]. Changchun:Jilin University, 2016. (in Chinese)
[12] WU P D, MACEWEN S R, LLOYD D J, et al. On pre-straining and the evolution of material anisotropy in sheet metals[J]. International Journal of Plasticity, 2005, 21(4):723-739.
[13] NAKA T, UEMORI T, HINO R, et al. Effects of strain rate, temperature and sheet thickness on yield locus of AZ31 magnesium alloy sheet[J]. Journal of Materials Processing Technology, 2008, 201(1-3):395-400.
[14] BARLAT F, BECKER R C, HSYASHIDA Y, et al. Yielding description for solution strengthened aluminum alloys[J]. International Journal of Plasticity, 1997, 13(4):385-401.
[15] BARLAT F, MAEDA Y, CHUNG K, et al. Yield function development for aluminum alloy sheets[J]. Journal of the Mechanics & Physics of Solids, 1997, 45(11-12):1727-1763.
[16] FRIEDEL J. Dislocations[M]. Oxford:Pergamon Press, 1964.
[17] GHOSH A K. A Physically-based constitutive model for metal deformation[J]. Acta Metallurgica, 1980, 28(11):1443-1465.