Effect of bake hardening on trace element segregation at grain boundary of Nb-Ti micro-alloyed steel

doi:10.13251/j.issn.0254-6051.2023.11.031

Abstract

Abstract: Effect of precipitation behavior during bake hardening on the mechanical properties of the bake hardening steel (HC180B) was investigated. The segregation behavior of dislocations, precipitates and atoms such as C and N at grain boundaries was studied by means of optical microscope (OM), transmission electron microscope (TEM) and three-dimensional atom probe (3DAP). The results show that the yield strength of 2% pre-tensile deformed specimen and that of the baked one is increased by 2 MPa and 73 MPa compared with that of the annealed cold-rolled plates, respectively. 3DAP and TEM results show that only C atoms in the annealed cold-rolled sheet are slightly segregated at the grain boundary, and N, Ti and Nb are evenly distributed in the grain. After 2% pre-stretching deformation, C, Ti and Nb are different degrees of segregation at the grain boundary. According to the difference between the Gibbs free energy and the atomic concentration at the grain boundary, it can be concluded that TiC is mostly rectangular and preferentially precipitates at the grain boundary, and NbC precipitates in a small amount. After 2% pre-stretching deformation and baking, the segregation of C, Ti and Nb at the grain boundary is more obvious, NbC precipitates in a large amount at the grain boundary in the form of an ellipsoid, TiC precipitates in a small amount, and the distribution of N atoms in different states is relatively uniform, while Ti and Nb carbides appear in the form of compound precipitation.

Key words: HC180B steel, atomic space distribution, segregation, grain boundary, carbides

CLC Number:

TG142.1

Song Qing, Wang Lihui, Pan Yingjun, Zhang Caidong, Huang Feng, Dong Yikang. Effect of bake hardening on trace element segregation at grain boundary of Nb-Ti micro-alloyed steel[J]. Heat Treatment of Metals, 2023, 48(11): 196-202.

References

[1]邝春福, 张深根, 李俊, 等. 烘烤硬化钢板的研究进展[J]. 材料导报, 2013, 27(9): 92-95.
Kuang Chunfu, Zhang Shengen, Li Jun, et al. Research process on bake hardenable steel sheet[J]. Materials Reports, 2013, 27(9): 92-95.
[2]Baker L J, Parker J D, Daniel S R. Principle of bake-hardening of Ti-Nb ultra-low-carbon steel[J]. Materials Science and Technology, 2002, 18(5): 541.
[3]高洪刚, 康海军. 连续退火工艺对冷轧烘烤硬化钢组织性能的影响[J]. 轧钢, 2018, 35(2): 42-44, 84.
Gao Honggang, Kang Haijun. Influence of continuous annealing process on cold rolled BH steel properties[J]. Steel Rolling, 2018, 35(2): 42-44.
[4]Opiela M, Fojt-Dymara G, Grajcar A, et al. Effect of grain size on the microstructure and strain hardening behavior of solution heat-treated low-C high-Mn steel[J]. Materials, 2020, 13(7): 1489.
[5]De Meira R R, Dias F M D S, Lins J F C. The influence of manganese on the bake hardening of hot dip galvanized low carbon steels[J]. Journal of Materials Research and Technology, 2020, 9(2): 2208-2213.
[6]Cho W, Jeong B S, Shin E, et al. Bake hardening and uniaxial tensile behavior in a low carbon steel accompanying inhomogeneous plastic yielding[J]. Materials Science and Engineering A, 2022, 856: 144004.
[7]付豪, 李维娟, 刘洋, 等. 低碳钢烘烤硬化中C元素晶界的偏聚[J]. 辽宁科技大学学报, 2015, 38(2): 98-103.
Fu Hao, Li Weijuan, Liu Yang, et al. Study on grain boundary segregation of carbon in bake hardening for low carbon steel[J]. Journal of University of Science and Technology Liaoning, 2015, 38(2): 98-103.
[8]胡学文, 陈继平, 康永林, 等. 超低碳BH钢的应变时效行为和烘烤硬化规律[J]. 金属热处理, 2019, 44(2): 30-34.
Hu Xuewen, Chen Jiping, Kang Yonglin, et al. Strain aging behavior and baking hardening law of ultra-low carbon BH steel[J]. Heat Treatment of Metals, 2019, 44(2): 30-34.
[9]Liu T, Hou H, Zhang X, et al. Effects of prestrain and grain boundary segregation of impurity atoms on bake hardening behaviors of Ti+V-bearing ultra-low carbon bake hardening steel[J]. Materials Science and Engineering A, 2018, 726: 160-168.
[10]韩荣, 刘洪喜, 尉文超, 等. Ti-V-Mo微合金化22MnB5钢中析出相及其强化作用[J]. 钢铁, 2022, 57(2): 127-138.
Han Rong, Liu Hongxi, Yu Wenchao, et al. Precipitates and their strengthening in Ti-V-Mo microalloyed 22MnB5 steel[J]. Iron and Steel, 2022, 57(2): 127-138.
[11]Song M, Kim J. Microstructural evolution at the initial stage of two-step aging in an Al-Mg-Si alloy characterized by a three dimensional atom probe[J]. Materials Science and Engineering A, 2021, 815: 141301.
[12]Gray V, Galvin D, Hill P, et al. Impact of targeted chemistries on maraging steel precipitation evolution observed using SANS and APT[J]. Materials Characterization, 2018, 139: 208-220.
[13]Oh J C, Ohkubo T, Mukai T, et al. TEM and 3DAP characterization of an age-hardened Mg-Ca-Zn alloy[J]. Scripta Materialia, 2005, 53(6): 675-679.
[14]韩文妥, 贺建超, 万发荣. ODS钢晶界偏析的三维原子探针分析[J]. 材料热处理学报, 2019, 40(11): 130-134.
Han Wentuo, He Jianchao, Wan Farong. School of Materials Science and Engineering[J]. Transactions of Materials and Heat Treatment, 2019, 40(11): 130-134.

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