Effect of austenitizing temperature on isothermal transformation and mechanical properties of bainite steel

doi:10.13251/j.issn.0254-6051.2022.04.013

Abstract

Abstract: Effect of austenitizing temperature on isothermal phase transformation kinetics, microstructure and mechanical properties of a medium carbon bainitic steel was studied by isothermal transformation test at 300 ℃ after austenitizing at 880-1050 ℃ with thermal dilatometer and thermal simulation testing machine. The results show that the increase of austenitizing temperature leads to the increase of grain size, the decrease of Ms point and the prolonging of the incubation period of bainite isothermal phase transformation. Decreasing the austenitizing temperature can significantly shorten the time of peak bainite transformation rate, indicating that lower austenitizing temperature is conducive to accelerating the bainite transformation. In the temperature range of this experiment, the specimens treated by austenitizing at 880 ℃ have excellent comprehensive mechanical properties, with the tensile strength of 1671 MPa and elongation of 13.3%.

Key words: bainite steel, austenitizing temperature, phase transformation kinetics, microstructure, mechanical properties

CLC Number:

TG142.1

Wang Yunlong, Yu Wei, Zhang Yi, Shi Jiaxin, Li Minghui. Effect of austenitizing temperature on isothermal transformation and mechanical properties of bainite steel[J]. Heat Treatment of Metals, 2022, 47(4): 80-85.

References

[1]Rees G I, Perdrix J, Maurickx T, et al. The effect of niobium in solid solution on the transformation kinetics of bainite[J]. Materials Science and Engineering A, 1995, 194(2): 179-186.
[2]Quidort D, Bréchet Y. The role of carbon on the kinetics of bainite transformation in steels[J]. Scripta Materialia, 2002, 47(3): 151-156.
[3]张超, 郭辉, 王家星, 等. 等温淬火温度对超细贝氏体钢组织及耐磨性的影响[J]. 工程科学学报, 2018, 40(12): 1502-1509.
Zhang Chao, Guo Hui, Wang Jiaxing, et al. Effect of austempering temperature on the microstructure and wear resistance of ultrafine bainitic steel[J]. Chinese Journal of Engineering, 2018, 40(12): 1502-1509.
[4]孙林, 洪振军, 胡坤, 等. 回火温度对不同淬火处理0.6C超级贝氏体钢组织及性能的影响[J]. 金属热处理, 2020, 45(10): 54-59.
Sun Lin, Hong Zhenjun, Hu Kun, et al. Effect of tempering temperature on microstructure and properties of 0.6C super bainitic steel quenched by different methods[J]. Heat Treatment of Metals, 2020, 45(10): 54-59.
[5]冯彦朋, 张弦, 吴开明, 等. 热处理工艺对超细贝氏体钢显微组织及耐腐蚀性能的影响[J]. 中国腐蚀与防护学报, 2021, 41(5): 602-608.
Feng Yanpeng, Zhang Xian, Wu Kaiming, et al. Influence of heat treatment process on microstructure and corrosion resistance of ultrafine bainite steel[J]. Journal of Chinese Society for Corrosion and Protection, 2021, 41(5): 602-608.
[6]高石, 潘学福. Nb对中低碳超级贝氏体钢组织与性能的影响[J]. 金属热处理, 2021, 46(12): 124-129.
Gao Shi, Pan Xuefu. Effect of Nb on microstructure and properties of medium low carbon super bainitic steel[J]. Heat Treatment of Metals, 2021, 46(12): 124-129.
[7]Liu W, Jiang Y H, Guo H, et al. Mechanical properties and wear resistance of ultrafine bainitic steel under low austempering temperature[J]. International Journal of Minerals, Metallurgy and Materials, 2020, 27(4): 483-493.
[8]Quidort D, Brechet Y. Isothermal growth kinetics of bainite in 0.5%C steels[J]. Acta Materialia, 2001, 49(20): 4161-4170.
[9]Oi K, Lux C, Purdy G R. A study of the influence of Mn and Ni on the kinetics of the proeutectoid ferrite reaction in steels[J]. Acta Materialia, 2000, 48(9): 2147-2155.
[10]Girault E, Jacques P, Ratchev P, et al. Study of the temperature dependence of the bainitic transformation rate in a multiphase TRIP-assisted steel[J]. Materials Science and Engineering A, 1999, 273-275: 471-474.
[11]张伟, 吴晓春, 闵永安. 奥氏体化温度对10Ni3MnCuAl钢贝氏体转变动力学的影响[J]. 材料热处理学报, 2008, 29(6): 78-81.
Zhang Wei, Wu Xiaochun, Min Yong'an. Effect of austenitizing temperature on bainite transformation kinetics in 10Ni3MnCuAl steel[J]. Transactions of Materials and Heat Treatment, 2008, 29(6): 78-81.
[12]Hase K, Garcia-Mateo C, Bhadeshia H K D H. Bainite formation influenced by large stress[J]. Materials Science and Technology, 2004, 20(12): 1499-1505.
[13]Shipway P H, Bhadeshia H K D H. The effect of small stresses on the kinetics of the bainite transformation[J]. Materials Science and Engineering A, 1995, 201(1/2): 143-149.
[14]Lan L Y, Qiu C L, Zhao D W, et al. Effect of austenite grain size on isothermal bainite transformation in low carbon microalloyed steel[J]. Materials Science and Technology, 2012, 27(11): 1657-1663.
[15]Lee S J, Park J S, Lee Y K. Effect of austenite grain size on the transformation kinetics of upper and lowerbainite in a low-alloy steel[J]. Scripta Materialia, 2008, 59(1): 87-90.
[16]Babu N K, Suresh M R, Sinha P P, et al. Effect of austenitizing temperature and cooling rate on the structure and properties of a ultrahigh strength low alloy steel[J]. Journal of Materials Science, 2006, 41(10): 2971-2980.
[17]何建国, 赵爱民, 黄耀, 等. 温轧工艺对纳米贝氏体相变速率、组织和力学性能的影响[J]. 材料研究学报, 2015, 29(3): 207-212.
He Jianguo, Zhao Aimin, Huang Yao, et al. Effect of warm rolling process on phase transformation, microstructure and mechanical properties of nano-bainite steel[J]. Chinese Journal of Materials Research, 2015, 29(3): 207-212.
[18]刘向东, 张国军, 车广东, 等. 奥氏体化温度对ZG30MnCrSi等温淬火组织与性能的影响[J]. 铸造技术, 2007, 28(6): 804-807.
Liu Xiangdong, Zhang Guojun, Che Guangdong, et al. Effects of austenitizing temperature on properties and microstructures of ZG30MnCrSi isothermal quenched[J]. Foundry Technology, 2007, 28(6): 804-807.
[19]Zhu K, Chen H, Masse J P, et al. The effect of prior ferrite formation onbainite and martensite transformation kinetics in advanced high-strength steels[J]. Acta Materialia, 2013, 61(16): 6025-6036.
[20]康沫狂, 朱明. 淬火合金钢中的奥氏体稳定化[J]. 金属学报, 2005, 41(7): 673-679.
Kang Mokuang, Zhu Ming. Stabilization of austenite in quenched alloy steels[J]. Acta Metallrugica Sinica, 2005, 41(7): 673-679.