Continuous cooling transformation law of V-Nb microalloyed Q420B large size angle steel

doi:10.13251/j.issn.0254-6051.2024.07.018

Abstract

Abstract: Continuous cooling transformation behavior of V-Nb microalloyed Q420B large angle steel was tested under undeformed (static) and deformed (dynamic) conditions by using thermal dilatometer and Gleeble-3500 thermal simulation machine. Microstructure of the tested steel after continuous cooling was observed by using optical microscope, and the static and dynamic CCT curves of the tested steel were plotted. The results show that the dynamic CCT curve of the tested steel moves to the upper left compared to the static CCT curve, indicating that the deformation accelerates the phase transformation of the tested steel and increases the starting and ending temperatures of the phase transformation. In addition, the deformation expands the pearlite transformation zone of the tested steel and reduces the bainite transformation zone. During the process of static and dynamic continuous cooling transformation, as the cooling rate increases, the microstructure of the tested steel gradually transforms from ferrite and pearlite to bainite and martensite formed under faster cooling rate conditions, and the hardness value of the tested steel gradually increases. Microstructure obtained after deformation of the tested steel in the austenitic unrecrystallized zone is uniformly finer than that obtained without deformation. An increase in the cooling rate results in a lower phase transformation temperature Ar₃ and finer ferrite grains, while at the same time the bainite microstructure is finer.

Key words: V-Nb microalloying, Q420B large size angle steel, continuous cooling transformation, static CCT curve, dynamic CCT curve

CLC Number:

TG142.1

Huang Jiantao, Zhang Minghe, Feng Yunli, Yin Shaojiang, Chen Chunsheng, Wang Houxin. Continuous cooling transformation law of V-Nb microalloyed Q420B large size angle steel[J]. Heat Treatment of Metals, 2024, 49(7): 121-127.

References

[1]常建伟, 徐德录, 张磊, 等. 输电铁塔用钢及其焊接技术[J]. 热加工工艺, 2011, 40(15): 148-151.
Chang Jianwei, Xu Delu, Zhang Lei, et al. Characteristics and welding technology of steel used for transmission line tower[J]. Hot Working Technology, 2011, 40(15): 148-151.
[2]黄璜, 李清华, 孟宪乔, 等. Q420大规格角钢在±800 kV特高压杆塔中的应用[J]. 电力建设, 2010, 31(6): 65-69.
Huang Huang, Li Qinghua, Meng Xianqiao, et al. Application on Q420 large width angle steel in ±800 kV UHV transmission tower[J]. Electric Power Construction, 2010, 31(6): 65-69.
[3]冯运莉, 刘战英, 陈春生, 等. VN合金在大规格角钢生产中的应用研究[J]. 钢铁钒钛, 2004, 25(2): 40-43.
Feng Yunli, Liu Zhanying, Chen Chunsheng, et al. Application of VN alloy in production of large size angle steel[J]. Iron Steel Vanadium Titanium, 2004, 25(2): 40-43.
[4]冯运莉, 段宝美, 胡小明, 等. V-N微合金化Q420B大规格角钢连铸坯高温热塑性的研究[J]. 热加工工艺, 2014, 43(16): 57-61.
Feng Yunli, Duan Baomei, Hu Xiaoming, et al. Study on high-temperature thermal plasticity of V-N microalloying Q420B large width angle steel continuous cast slab[J]. Hot Working Technology, 2014, 43(16): 57-61.
[5]马壮, 侯振伟, 陈雪慧, 等. Nb对V-N微合金化钢高温热塑性的影响[J]. 钢铁研究学报, 2022, 34(10): 1177-1186.
Ma Zhuang, Hou Zhenwei, Chen Xuehui, et al. Effect of Nb on hot ductility of V-N microalloyed steel[J]. Journal of Iron and Steel Research, 2022, 34(10): 1177-1186.
[6]蒲春雷, 姜嫄, 闫洞旭, 等. Nb/V/Ti微合金化对20MnSi钢组织和力学性能影响[J]. 材料热处理学报, 2023, 44(7): 99-106.
Pu Chunlei, Jiang Yuan, Yan Dongxu, et al. Effect of Nb/V/Ti microalloying on microstructure and mechanical properties of 20MnSi steel[J]. Transactions of Materials and Heat Treatment, 2023, 44(7): 99-106.
[7]徐海峰, 李海, 李凤敏, 等. 新型槽帮钢的连续冷却转变曲线及微观组织[J]. 金属热处理, 2023, 48(6): 191-196.
Xu Haifeng, Li Hai, Li Fengmin, et al. Continuous cooling transformation curves and microstructure of new-type slot edge steel[J]. Heat Treatment of Metals, 2023, 48(6): 191-196.
[8]赵倩, 乔志霞, 董纪, 等. WB36CN1钢连续冷却转变产物分析[J]. 金属热处理, 2023, 48(7): 22-25.
Zhao Qian, Qiao Zhixia, Dong Ji, et al. Analysis of continuous cooling transformation products of WB36CN1 steel[J]. Heat Treatment of Metals, 2023, 48(7): 22-25.
[9]马启林, 刘刚, 郑健, 等. Nb-V复合微合金化高钢级管线钢的奥氏体连续冷却转变[J]. 金属热处理, 2022, 47(1): 13-18.
Ma Qilin, Liu Gang, Zheng Jian, et al. Continuous cooling transformation of austenite in Nb-V microalloyed high-grade pipeline steel[J]. Heat Treatment of Metals, 2022, 47(1): 13-18.
[10]阎勇, 李萌蘖, 卜恒勇, 等. S34MnV钢的连续冷却转变行为及相变动力学研究[J]. 材料导报, 2021, 35(20): 20129-20136.
Yan Yong, Li Mengnie, Bu Hengyong, et al. Continuous cooling transformation behavior and transformation kinetics of S34MnV steel[J]. Materials Reports, 2021, 35(20): 20129-20136.

[1]	Chen Zuoning, Shi Zhongran, Hu Qian, Zhan Zhide, Luo Xiaobing. Continuous cooling transformation of austenite in 390 MPa grade anti-collision hull steel [J]. Heat Treatment of Metals, 2024, 49(7): 146-151.
[2]	Tong Yang, Zhang Jing, Xin Wenbin, Luo Guoping, Peng Jun, Hou Dengyun. Effect of Nb content on continuous cooling transformation rule, microstructure and properties of V-Ti-N structural steel [J]. Heat Treatment of Metals, 2024, 49(3): 236-243.
[3]	Wang Zhilin, Gao Xing, Jiang Bo, Wang Leiying, Zhao Haidong, Wu Han. Continuous cooling transformation and microstructure control of a Mn-Cr-V-S bainitic non-quenched and tempered steel [J]. Heat Treatment of Metals, 2023, 48(9): 191-196.
[4]	Zhao Qian, Qiao Zhixia, Dong Ji, Zhang Yaran, He Biao, Qian Kuo. Analysis of continuous cooling transformation products of WB36CN1 steel [J]. Heat Treatment of Metals, 2023, 48(7): 22-25.
[5]	Tan Huijie, Bao Xiaoguang, Wu Zhongwang, Wang Haiyan. Transformation law of super-cooled austenite and phase transformation model of X80 pipeline steel [J]. Heat Treatment of Metals, 2023, 48(7): 61-65.
[6]	Xu Haifeng, Li Hai, Li Fengmin, Fu Shengmin, Ming Keyu, Yu Yan. Continuous cooling transformation curves and microstructure of new-type slot edge steel [J]. Heat Treatment of Metals, 2023, 48(6): 191-196.
[7]	Wang Xinzhi, Zhang Ke, Huang Zhong, Xu Dangwei, Du Haiming, Zhang Xiaofeng, Zhang Xi. Continuous cooling transformation of Cr-Ni-Cu bridge weathering steel and its microstructure and hardness [J]. Heat Treatment of Metals, 2023, 48(2): 17-22.
[8]	Wang Ruimin, Liu Man, Zhou Jianhua, Zhang Qi, Su Xue, Xu Guang. Continuous cooling transformation curve of R350HT rail steel [J]. Heat Treatment of Metals, 2022, 47(9): 153-157.
[9]	Shen Hui, Liu Yunpeng, Si Tingzhi. Microstructure transformation characteristic of 4330M steel during continuous cooling process [J]. Heat Treatment of Metals, 2022, 47(7): 190-196.
[10]	Wu Keyuan, Liu Yunpeng, Li Kongzhai, Xu Liangle. Continuous cooling transformation and phase transformation kinetics of 17-4PH stainless steel [J]. Heat Treatment of Metals, 2022, 47(6): 161-167.
[11]	Pang Qinghai, Lang Qingbin, He Chunjing, Wang Jiuhua, Yuan Yasha. Phase transformation and mechanical properties of 5Cr2NiMoVSi die steel [J]. Heat Treatment of Metals, 2022, 47(3): 186-190.
[12]	Ma Qilin, Liu Gang, Zheng Jian, Yin Shubiao, Li Ba, Liu Qingyou. Continuous cooling transformation of austenite in Nb-V microalloyed high-grade pipeline steel [J]. Heat Treatment of Metals, 2022, 47(1): 13-18.
[13]	Tao Sufen, Wu Hao, Sun Guilin, Chen Long, Chen Bo. Effect of Ni content on continuous cooling transformation curves of EQ70 steel for marine engineering [J]. Heat Treatment of Metals, 2022, 47(1): 100-105.
[14]	Huo Xiwei. Effect of Cr on dynamic CCT curves and properties of 20MnSiV gantry steel [J]. Heat Treatment of Metals, 2021, 46(7): 89-93.
[15]	Huo Jiansheng, Yan Dong. Continuous cooling transformation behavior of undercooled austenite of 700 MPa high strength weathering resistance steel [J]. Heat Treatment of Metals, 2021, 46(7): 94-97.