Evolution of reversed austenite in ultra-low carbon bainitic steel during intercritical tempering

doi:10.13251/j.issn.0254-6051.2024.03.031

Abstract

Abstract: An ultra-low carbon bainitic steel was tempered in the dual-phase region for different time after quenching. The evolution of reversed austenite and the distribution of Ni and Mn elements in the matrix and in the reversed austenite were studied by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), transmission electron microscope (TEM) and X-ray stress meter. The results show that the matrix of the quenched specimen is lath bainite with a small amount of retained austenite. With the extension of tempering time, reversed austenite appears in the matrix, and the content increases first and then decreases, and the morphology changes from film-like to strip-like. When the tempering time is up to 240 min, the reversed austenite in the matrix is the most stable and the content is the highest, about 15.6%. The content of Ni and Mn in the reversed austenite is 15.23% and 1.42%, respectively, which is much higher than that of the matrix. When the tempering time is 1440 min, the content of reversed austenite decreases to 5.50%, and the partially reversed austenite is unstable and transforms into new martensite. The contents of Ni and Mn are 12.58% and 1.21%, respectively, which is slightly lower than those in the most stable reversed austenite.

Key words: intercritical tempering, microstructure, lath bainite, reversed austenite, fresh martensite

CLC Number:

TG142.1

Yang Ying, Pan Shiliang, Xu Yuanyuan, Wang Zemin, Wang Zhanyong. Evolution of reversed austenite in ultra-low carbon bainitic steel during intercritical tempering[J]. Heat Treatment of Metals, 2024, 49(3): 182-189.

References

[1]Ma J, Song Y Y, Jiang H C, et al. Effect of Cu on the microstructure and mechanical properties of a low-carbon martensitic stainless steel[J]. Materials (Basel), 2022, 15(24): 8849.
[2]周成, 赵坦, 叶其斌, 等. 回火温度对1000 MPa级NiCrMoV低碳合金钢微观组织和低温韧性的影响[J]. 金属学报, 2022, 58(12): 1557-1569.
Zhou Cheng, Zhao Tan, Ye Qibin, et al. Effect of tempering temperature on microstructure and low-temperature toughness of 1000 MPa grade NiCrMoV low carbon alloy steel[J]. Acta Metallurgica Sinica, 2022, 58(12): 1557-1569.
[3]He Z Y, Wang P, Liu G M, et al. The phase transformation in a low-carbon 13Cr4Ni martensitic stainless steel during two-stageintercritical tempering[J]. Metals, 2023, 13(7): 1302.
[4]Nakanishi D, Kawabata T, Aihara S. Effect ofdispersed retained γ-Fe on brittle crack arrest toughness in 9%Ni steel in cryogenic temperatures[J]. Materials Science and Engineering A, 2018, 723: 238-246.
[5]战国锋, 刘继雄, 肖建中, 等. Cu 及热处理工艺对 9Ni 钢组织及性能的影响[J]. 材料热处理学报, 2015, 36(8): 139-143.
Zhan Guofeng, Liu Jixiong, Xiao Jianzhong, et al. Influence of addition of Cu and heat treatment on microstructure and properties of 9Ni steel[J]. Transactions of Materials and Heat Treatment, 2015, 36(8): 139-143.
[6]熊庆人, 霍春勇, 李为卫, 等. 9%Ni钢亚温淬火处理工艺参数试验研究[J]. 材料热处理学报, 2017, 38(2): 136-142.
Xiong Qingren, Huo Chunyong, Li Weiwei, et al. Experimental investigation of intercritical hardening of a 9%Ni steel[J]. Transactions of Materials and Heat Treatment, 2017, 38(2): 136-142.
[7]张坤, 唐荻, 武会宾, 等. 两相区淬火对 9Ni 钢中逆转变奥氏体的影响[J]. 材料热处理学报, 2012, 33(8): 59-63.
Zhang Kun, Tang Di, Wu Huibin, et al. Effect of quenching in dual-phase region on the reversed austenite in 9Ni steel[J]. Transactions of Materials and Heat Treatment, 2012, 33(8): 59-63.
[8]谢章龙, 陈锋, 胡其龙, 等. 奥氏体化及回火温度对E550级低温钢组织和性能的影响[J]. 金属热处理, 2021, 46(1): 65-70.
Xie Zhanglong, Chen Feng, Hu Qilong, et al. Influence of austenitizing and tempering temperature on microstructure and properties of E550 low-temperature steel[J]. Heat Treatment of Metals, 2021, 46(1): 65-70.
[9]李员妹, 孙新军, 雍岐龙, 等. 回火温度对5.5Ni低温钢组织和力学性能的影响[J]. 材料研究学报, 2015, 29(11): 860-866.
Li Yuanmei, Sun Xinjun, Yong Qilong, et al. Effect of tempering temperature on microstructure and mechanical properties of 5.5Ni cryogenic steel[J]. Chinese Journal of Materials Research, 2015, 29(11): 860-866.
[10]Wang J, Li W, Zhu X D, et al. Effect of martensite morphology and volume fraction on the low-temperature impact toughness of dual-phase steels[J]. Materials Science and Engineering A, 2022, 832: 142424.
[11]田景云, 洪波, 沈俊昶. 回火温度对 9NiCrMo 钢性能和组织的影响[J]. 钢铁钒钛, 2013, 34(6): 101-105.
Tian Jingyun, Hong Bo, Shen Junxu. Effect of tempering temperature on microstructure and properties of 9NiCrMo steel[J]. Iron Steel Vanadium Titanium, 2013, 34(6): 101-105.
[12]Sk M B, Alam I, Chakrabarti D. The role of fibrous morphology on the charpy impact properties of low carbon ferrite-bainite dual phase steel[J]. Materials Science and Engineering A, 2018, 716: 208-219.
[13]程久珊, 刘静, 镇凡, 等. 含Cu的Mn-Nb-B系超低碳贝氏体钢的强韧化机理[J]. 有色金属(冶炼部分), 2011(7): 39-42.
Cheng Jiushan, Liu Jing, Zhen Fan, et al. High strength and toughness mechanism of ultra-low carbon bainitic steel containing Cu in Mn-Nb-B micro-alloy[J]. Nonferrous Metals (Extractive Metallurgy), 2011(7): 39-42.
[14]Zhang Y W, Zhang C, Yuan X M, et al. Microstructure evolution and orientation relationship of reverted austenite in 13Cr supermartensitic stainless steel during the tempering process[J]. Materials (Basel), 2019, 12(4): 589.
[15]徐海峰, 李海, 李凤敏, 等. 合金元素及热处理对新型槽帮钢组织与性能的影响[J]. 金属热处理, 2023, 48(4): 148-154.
Xu Haifeng, Li Hai, Li Fengmin, et al. Effects of alloy element and heat treatment on microstructure and properties of new-type slot edge steel[J]. Heat Treatment of Metals, 2023, 48(4): 148-154.
[16]Escobar J D, Poplawsky J D, Faria G A, et al. Compositional analysis on the reverted austenite and tempered martensite in a Ti-stabilized supermartensitic stainless steel: Segregation, partitioning and carbide precipitation[J]. Materials and Design, 2018, 140: 95-105.
[17]黄曦, 上官昌平, 王泽民, 等. QLT 工艺对新型车轴钢显微组织与性能的影响[J]. 现代交通与冶金材料, 2022, 2(5): 40-45.
Huang Xi, Shangguan Changping, Wang Zemin, et al. Effect of QLT process on microstructure and properties of new axle steel[J]. Modern Transportation and Metallurgical Materials, 2022, 2(5): 40-45.
[18]Tavares S S, Bastos I N, Pardal J M, et al. Slow strain rate tensile test results of new multiphase 17% Cr stainless steel under hydrogen cathodic charging[J]. International Journal of Hydrogen Energy, 2015, 40(47): 16992-16999.
[19]Escobar J D, Faria G A, Wu L, et al. Austenite reversion kinetics and stability during tempering of a Ti-stabilizedsupermartensitic stainless steel: Correlative in situ synchrotron X-ray diffraction and dilatometry[J]. Acta Materialia, 2017, 138: 92-99.
[20]Nakada N, Tsuchiyama T, Takaki S, et al. Temperature dependence of austenite nucleation behavior from lath martensite[J]. ISIJ International, 2011, 51(2): 299-304.
[21]杨跃辉, 武会宾, 蔡庆伍, 等. 9Ni 钢中回转奥氏体的形成规律及其稳定性[J]. 材料热处理学报, 2010, 31(3): 73-77.
Yang Yuehui, Wu Huibin, Cai Qingwu, et al. Formation of reversed austenite and its stability in 9Ni steel during tempering[J]. Transactions of Materials and Heat Treatment, 2010, 31(3): 73-77.
[22]赵帅, 李青春, 安昊瀛, 等. Cr13Ni4Mo 钢逆转变奥氏体的形成及其对性能的影响[J]. 金属热处理, 2023, 48(1): 95-100.
Zhao Shuai, Li Qingchun, An Haoying, et al. Formation of reversed austenite and its effect on properties of Cr13Ni4Mo steel[J]. Heat Treatment of Metals, 2023, 48(1): 95-100.
[23]Govindaraj V, Hodgson P, Singh R P, et al. The effect of austenite reversion on the microstructure and mechanical properties of a 12Cr-3Ni-3Mn-3Cu-0.15Nb-0.05C maraging stainless steel[J]. Materials Science and Engineering A, 2021, 828: 142097.
[24]Gruber M, Ploberger S, Ressel G, et al. Effects of the combined heat and cryogenic treatment on the stability of austenite in a high Co-Ni steel[J]. Archives of Metallurgy and Materials, 2015, 60(3): 2131-2137.
[25]Huang X, Wang L B, Wang Z M, et al. Effect of temperature on microstructure and mechanical properties of Fe-9Ni-2Cu Steel during the tempering process[J]. Materials (Basel), 2021, 14(23): 7141.
[26]Rodrigues P, Pereloma E V, Santos D. Mechanical properities of an HSLA bainitic steel subjected to controlled rolling with accelerated cooling[J]. Materials Science and Engineering A, 2000, 283(1): 136-143.
[27]Kim Y M, Kim S K, Lim Y J. Effect of microstructure on the yield ratio and low temperature toughness of linepipe steels[J]. ISIJ International, 2002, 42(12): 1571-1577.
[28]许亚娟, 周清跃, 陈朝阳, 等. 回火工艺对 1200 MPa 级贝氏体钢轨组织性能的影响[J]. 材料热处理学报, 2012, 33(S1): 72-76.
Xu Yajuan, Zhou Qingyue, Chen Zhaoyang, et al. Influence of temper technology on mechanical properties and microstructure of 1200 MPa bainite rail steel[J]. Transactions of Materials and Heat Treatment, 2012, 33(S1): 72-76.
[29]Govindaraj V, Hodgson P, Singh R P, et al. The effect of austenite reversion on the microstructure and mechanical properties of a 12Cr-3Ni-3Mn-3Cu-0.15Nb-0.05C maraging stainless steel[J]. Materials Science and Engineering A, 2021, 828: 142097.
[30]Wang Z M, Dong Y, Li J J, et al. The role of cold rolling reduction on the microstructure and mechanical properties of ultra-low carbon bainitic steel[J]. Materials, 2022, 15(9): 3070.
[31]张坤, 唐荻, 武会宾. 回火保温时间对 9Ni 钢逆转变奥氏体和低温韧性的影响[J]. 金属热处理, 2012, 37(3): 85-88.
Zhang Kun, Tang Di, Wu Huibin. Effect of tempering time on reversed austenite and cryogenic toughness of 9Ni steel[J]. Heat Treatment of Metals, 2012, 37(3): 85-88.
[32]Chen Q Y, Zhang W N, Xie Z L, et al. Influence of intercritical temperature on the microstructure and mechanical properties of 6.5 pct Ni steel processed by ultra-fast cooling, intercritical quenching and tempering[J]. Metallurgical and Materials Transactions A, 2020, 51(6): 3030-3041.
[33]谭昊, 崔熙, 贾潇, 等. 中锰钢残留奥氏体稳定性影响因素分析[J]. 焊管, 2019, 42(4): 54-60.
Tan Hao, Cui Xi, Jia Xiao, et al. Analysis of factors affecting stability of retained austenite in medium manganese steel[J]. Welded Pipe and Tube, 2019, 42(4): 54-60.
[34]Zhang S H, Wang P, Li D Z, et al. Investigation of the evolution of retained austenite in Fe-13%Cr-4%Ni martensitic stainless steel during intercritical tempering[J]. Materials and Design, 2015, 84: 385-394.
[35]Han G, Hu B, Yu Y S, et al. Atomic-scale studyon the mechanism of formation of reverted austenite and the behavior of Mo in a low carbon low alloy system[J]. Materials Characterization, 2020, 163: 110269.
[36]杨跃辉, 苑少强, 梁国俐, 等. 回火温度对超低碳7%Mn 钢组织与性能的影响[J]. 金属热处理, 2022, 46(10): 168-172.
Yang Yuehui, Yuan Shaoqiang, Liang Guoli, et al. Effect of tempering temperature on microstructure and properties of ultra low carbon 7%Mn steel[J]. Heat Treatment of Metals, 2022, 46(10): 168-172.
[37]王六定, 郑建邦, 陈彦, 等. 逆转变奥氏体形成动力学研究[J]. 西北工业大学学报, 1999, 17(2): 226-229.
Wang Liuding, Zheng Jianbang, Chen Yan, et al. Study on formation kinetics of reversed austenite[J]. Journal of Northwestern Polytechnical University, 1999, 17(2): 226-229.
[38]Hou W, Liu Q D, Wen H M, et al. Effect of cyclicintercritical tempering on the microstructure and mechanical properties of a low-carbon Cu-bearing 7Ni steel[J]. Metallurgical and Materials Transactions A, 2020, 51(8): 3981-3995.