Continuous cooling transformation behavior of high strength bridge steel Q690q

doi:10.13251/j.issn.0254-6051.2022.09.035

Abstract

Abstract: Continuous cooling transformation behaviors of high strength bridge steel Q690q were studied under three different primary austenite states of fine-grained austenite (grain size of grade 10), coarse-grained austenite (grain size of grade 6.5) and fine-grained deformed austenite (grain size of grade 10.5 and 30% compression deformation) by means of MMS-200 thermo simulator, Imager M2m optical microscope, JSM-6490LV scanning electron microscope and FV-ARS9000 automatic Vickers hardness tester. The results show that when the cooling rate is the same, fine-grained austenite increases phase transformation starting temperature, transformation rate peak temperature and phase transformation finishing temperature, while coarse-grained austenite contributes to the formation of medium and low temperature structures, such as lath bainite and lath martensite, and the lath becomes more elongated, but the prior austenite grain boundary becomes clearer, and its hardness obviously improves. Meanwhile, after the fine grain austenite deformation, the phase transformation starting temperature and transformation rate peak temperature are higher, so that the ferrite becomes bulky, but that can reduce the pearlite transformation and promote the formation of carbon-free bainite, and the hardness is greater than the condition of fine-grained austenite at lower cooling rate, and there is no difference when the cooling rate is higher.

Key words: bridge steel Q690q, controlled cooling, microstructure, phase transformation

CLC Number:

TG142.1

Zhou Wenhao. Continuous cooling transformation behavior of high strength bridge steel Q690q[J]. Heat Treatment of Metals, 2022, 47(9): 202-207.

References

[1]Qin Shunquan, Gao Zongyu. Developments and prospects of long-span high-speed railway bridge technologies in China[J]. Engineering, 2017, 3(6): 23-38.
[2]郑凯锋, 张宇, 衡俊霖, 等. 高强度耐候钢及其在桥梁中的应用与前景[J]. 哈尔滨工业大学学报, 2020, 52(3): 1-10.
Zheng Kaifeng, Zhang Yu, Heng Junlin, et al. High strength weathering steel and its application and prospect in bridge engineering[J]. Journal of Harbin Institute of Technology, 2020, 52(3): 1-10.
[3]彭宁琦, 何航, 罗登, 等. 高强韧耐候桥梁钢Q500qENH的生产工艺[J]. 金属热处理, 2021, 46(8): 139-144.
Peng Ningqi, He Hang, Luo Deng, et al. Production process of high strength and toughness weather-resistant bridge steel Q500qENH[J]. Heat Treatment of Metals, 2021, 46(8): 139-144.
[4]易伦雄, 袁毅, 彭最. 690 MPa级高性能桥梁钢工程应用[J]. 桥梁建设, 2021, 51(5): 14-19.
Yi Lunxiong, Yuan Yi, Peng Zui. Engineering application of 690 MPa high-performance bridge steel[J]. Bridge Construction, 2021, 51(5): 14-19.
[5]ASTM A709/A709M—18, Standard specification for structural steel for bridges[S].
[6]熊文娟. Q690桥梁钢实验室TMCP轧制工艺及轧后热处理的研究[D]. 武汉: 武汉科技大学, 2012.
[7]陈康, 左秀荣, 李源, 等. 调质处理对低碳微合金钢组织与力学性能的影响[J]. 金属热处理, 2014, 39(9): 5-9.
Chen Kang, Zuo Xiurong, Li Yuan, et al. Effects of quenching and tempering on microstructure and mechanical properties of low-carbon microalloyed steel[J]. Heat Treatment of Metals, 2014, 39(9): 5-9.
[8]张跃飞, 王坤, 张学峰, 等. 薄规格12MnNiVR储罐钢低屈强比控制策略[J]. 金属热处理, 2022, 47(6): 173-177.
Zhang Yuefei, Wang Kun, Zhang Xuefeng, et al. Low yield ratio control strategy for thin 12MnNiVR storage tank steel plate[J]. Heat Treatment of Metals, 2022, 47(6): 173-177.
[9]中铁大桥勘测设计院集团有限公司. 武汉江汉七桥工程施工图设计[Z]. 武汉, 2018.
China Railway Major Bridge Reconnaissance and Design Institute Co., Ltd. Construction drawings ofwuhan hanjiang 7th bridge[Z]. Wuhan, 2018.
[10]镇凡, 张宽, 李玉藏, 等. 控轧控冷工艺对低焊接裂纹敏感性高强钢Q800CFE屈强比的影响[J]. 金属热处理, 2015, 40(2): 118-124.
Zhen Fan, Zhang Kuan, Li Yucang, et al. Effect of controlled rolling and controlled cooling process on the yield ratio of high strength steel Q800CFE with low welding crack sensibility[J]. Heat Treatment of Metals, 2015, 40(2): 118-124.
[11]Zhao H, Wynne B P, Palmiere E J. Effect of austenite grain size on the bainitic ferrite morphology and grain refinement of a pipeline steel after continuous cooling[J]. Materials Characterization, 2017, 123: 128-136.
[12]宋韶杰. 扩散型固态相变动力学与热力学研究[D]. 西安: 西北工业大学, 2015.
[13]余永宁. 金属学原理[M]. 北京: 冶金工业出版社, 2000.
[14]Jiao Benqi, Zhao Qinyang, Zhao Yongqing, et al. The relationship between slip behavior and dislocation arrangement for large-size Mo-3Nb single crystal at room temperature[J]. Journal of Materials Science and Technology, 2021, 92(33): 208-213.
[15]Long Xiaoyan, Zhang Ruijie, Zhang Fucheng, et al. Study on quasi-in-situ tensile deformation behavior in medium-carbon carbide-free bainitic steel[J]. Materials Science and Engineering A, 2019, 760: 158-164.
[16]霍建生, 阎冬. 700 MPa级高强度耐候钢过冷奥氏体连续冷却相变行为[J]. 金属热处理, 2021, 46(7): 94-98.
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): 94-98.
[17]周松波, 胡锋, 尹朝朝, 等. 块状组织细化对贝氏体钢断裂行为的影响[J]. 钢铁, 2020, 55(11): 103-111.
Zhou Songbo, Hu Feng, Yin Chaochao, et al. Effect of refinement of bulk structure on fracture behavior of bainitic steel[J]. Iron and Steel, 2020, 55(11): 103-111.
[18]王群, 唐荻, 宋勇, 等. DP590钢线膨胀测量中相转变体积分数的分析[J]. 金属热处理, 2013, 38(1): 108-112.
Wang Qun, Tang Di, Song Yong, et al. Analysis of volume fraction during phase transformation process in linear thermal expansion measurement of dual-phase 590 steel[J]. Heat Treatment of Metals, 2013, 38(1): 108-112.