Continuous cooling transformation of Cr-Ni-Cu bridge weathering steel and its microstructure and hardness

doi:10.13251/j.issn.0254-6051.2023.02.003

Abstract

Abstract: In order to understand the changes of microstructure and hardness of Cr-Ni-Cu bridge weathering steel during continuous cooling transformation (CCT) and the causes, the CCT curves and time-temperature-transformation(TTT) curves were simulated and calculated by the JMatPro software. Microstructure and hardness of the Cr-Ni-Cu bridge weathering steel during CCT process were investigated by means of Gleeble-3800 hot-simulated test machine, optical microscope (OM), scanning electron microscope (SEM) and hardness tester, and the influencing mechanisms of cooling rate on microstructure, hardness and phase transformation behavior were discussed. The results show that after 1050 ℃ and 860 ℃ two-stage high temperature deformation, as the cooling rate increases from 0.1 ℃/s to 30 ℃/s, the microstructures of Cr-Ni-Cu bridge weathering steel are successively evolving from polygonal ferrite+pearlite→polygonal ferrite+bainite→granular bainite→granular bainite+martensite, and the hardness increases gradually from 155 HV0.2 to 373 HV0.2. When the cooling rate increases from 0.1 ℃/s to 3 ℃/s, the increase of hardness is mainly due to the refinement of polygonal ferrite grains. While the cooling rate increases from 5 ℃/s to 30 ℃/s, the increase of hardness is attributed to the continuous refinement of bainite microstructure and the consistent increase of martensite content.

Key words: bridge weathering steel, continuous cooling transformation, cooling rate, hardness, bainite

CLC Number:

TG142.1

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.

References

[1]程鹏, 黄先球, 庞涛, 等. 耐候桥梁钢的研究现状与发展趋势[J]. 材料保护, 2020, 53(7): 142-146.
Cheng Peng, Huang Xianqiu, Pang Tao, et al. Research status and development trend of weather resistant bridge steel[J]. Materials Protection, 2020, 53(7): 142-146.
[2]田志强, 孙力, 刘建磊, 等. 国内外耐候桥梁钢的发展现状[J]. 河北冶金, 2019(2): 11-13, 25.
Tian Zhiqiang, Sun Li, Liu Jianlei, et al. Development status of weather-resistant bridge steel at home and abroad[J]. Hebei Metallurgy, 2019(2): 11-13, 25.
[3]吴智深, 刘加平, 邹德辉, 等. 海洋桥梁工程轻质、高强、耐久性结构材料现状及发展趋势研究[J]. 中国工程科学, 2019, 21(3): 31-40.
Wu Zhishen, Liu Jiaping, Zou Dehui, et al. Research on current situation and development trend of light weight, high strength and durability structural materials for ocean bridge engineering[J]. Engineering Sciences, 2019, 21(3): 31-40.
[4]范益. Q500EHPS桥梁钢力学性能和耐蚀性能的调控研究[D]. 秦皇岛: 燕山大学, 2017.
Fan Yi. Study on controlling of mechanical and corrosion-resistance properties of Q500EHPS steel for bridge[D]. Qinhuangdao: Yanshan University, 2017.
[5]邱福祥, 艾爱国, 罗松云, 等. 高强度桥梁钢Q500qE板材焊接性能研究[J]. 金属材料与冶金工程, 2017, 45(3): 10-14, 18.
Qiu Fuxiang, Ai Aiguo, Luo Songyun, et al. Study on welding performance of Q500qE plate of high strength bridge steel[J]. Metal Materials and Metallurgy Engineering, 2017, 45(3): 10-14, 18.
[6]赵丽洋, 刘东博, 谯明亮, 等. Q500qENH耐候桥梁钢形变奥氏体连续冷却转变行为研究[J]. 上海金属, 2022, 44(1): 35-39.
Zhao Liyang, Liu Dongbo, Qiao Mingliang, et al. Study on continuous cooling transformation behavior of deformed austenite in Q500qENH weather-resistant bridge steel[J]. Shanghai Metals, 2022, 44(1): 35-39.
[7]Chen J, Tang S, Liu Z Y, et al. Influence of molybdenum content on transformation behavior of high performance bridge steel during continuous cooling[J]. Materials and Design, 2013, 49: 465-470.
[8]Cheng P, Liu J, Huang X Q, et al. Effect of silicon on the corrosion behaviour of 690 MPa weathering bridge steel in simulated industrial atmosphere[J]. Construction and Building Materials, 2022, 328: 127030.
[9]Guo J, Shang C J, Yang S W, et al. Effect of carbon content on mechanical properties and weather resistance of high performance bridge steels[J]. Journal of Iron and Steel Research, International, 2009, 16(6): 63-69.
[10]Cao R, Han C, Guo X L, et al. Effects of boron on the microstructure and impact toughness of weathering steel weld metals and existing form of boron[J]. Materials Science & Engineering A, 2022, 833: 142560.
[11]熊文娟. Q690q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.
Xiong Wenjuan. Study on TMCP schedule and heat treatment for Q690q bridge steel[D]. Wuhan: Wuhan University of Science and Technology, 2012.
[12]姬凤芹, 利成宁, 唐帅, 等. 低成本减量化Q690qENH高强桥梁钢的开发[J]. 中国冶金, 2015, 25(4): 1-6, 32.
Ji Fengqin, Li Chengning, Tang Shuai, et al. Development of low cost reduced Q690qENH high strength bridge steel[J]. China Metallurgy, 2015, 25(4): 1-6, 32.
[13]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.
[14]白星, 钱亚军, 刘吉文, 等. 低屈强比桥梁用钢Q420qE的研究与开发[J]. 金属热处理, 2019, 44(8): 106-109.
Bai Xing, Qian Yajun, Liu Jiwen, et al. Research and development of bridge steel Q420qE with low yield ratio[J]. Heat Treatment of Metals, 2019, 44(8): 106-109.
[15]周文浩. 高强度桥梁钢Q690q的连续冷却转变行为[J]. 金属热处理, 2022, 47(9): 202-208.
Zhou Wenhao. Continuous cooling transformation behavior of high strength bridge steel Q690q[J]. Heat Treatment of Metals, 2022, 47(9): 202-208.
[16]张可, 叶晓瑜, 李昭东, 等. 铁素体基Ti-Mo高强钢连续冷却相变及组织性能[J]. 钢铁研究学报, 2019, 31(8): 733-740.
Zhang Ke, Ye Xiaoyu, Li Zhaodong, et al. Continuous cooling transformation and microstructure and properties of ferritic Ti-Mo high strength steel[J]. Journal of Iron and Steel Research, 2019, 31(8): 733-740.
[17]Chen C Y, Yang J R, Chen C C, et al. Microstructural characterization and strengthening behavior of nanometer sized carbides in Ti-Mo microalloyed steels during continuous cooling process[J]. Materials Characterization, 2016, 114: 18-29.
[18]张可, 李昭东, 隋凤利, 等. 冷却速率对Ti-V-Mo复合微合金钢组织转变及力学性能的影响[J]. 金属学报, 2018, 54(1): 31-38.
Zhang Ke, Li Zhaodong, Sui Fengli, et al. Effect of cooling rate on microstructure transformation and mechanical properties of Ti-V-Mo composite microalloyed steel[J]. Acta Metallurgica Sinica, 2018, 54(1): 31-38.
[19]Karmakar A, Sahu P, Neogy S, et al. Effect of cooling rate and chemical composition on microstructure and properties of naturally cooled vanadium-microalloyed steels[J]. Metallurgical and Materials Transactions, A-Physical Metallurgy and Materials Science, 2017, 48(4): 1581-1595.
[20]Tong M M, Li D Z, Li Y Y. Modeling the austenite-ferrite diffusive transformation during continuous cooling on a mesoscale using Monte Carlo method[J]. Acta Materialia, 2004, 52(5): 1155-1162.
[21]高新亮, 肖瑶, 韩毅, 等. Cr元素对桥梁耐候钢相变行为的影响[J]. 燕山大学学报, 2018, 42(2): 119-124.
Gao Xinliang, Xiao Yao, Han Yi, et al. Effect of Cr element on phase transformation behavior of bridge weathering steel[J]. Journal of Yanshan University, 2018, 42(2): 119-124.