| 引用本文: | 徐党委,黄重,张可,魏宏宇,夏志升,杜海明,张明亚.热输入对Q550qENH钢焊接热模拟CGHAZ组织和力学性能的影响[J].材料科学与工艺,2026,(2):78-85.DOI:10.11951/j.issn.1005-0299.20240163. |
| XU Dangwei,HUANG Zhong,ZHANG Ke,WEI Hongyu,XIA Zhisheng,DU Haiming,ZHANG Mingya.Effect of heat input on microstructure and mechanical properties of CGHAZ in welding thermal simulation of Q550qENH steel[J].Materials Science and Technology,2026,(2):78-85.DOI:10.11951/j.issn.1005-0299.20240163. |
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| 热输入对Q550qENH钢焊接热模拟CGHAZ组织和力学性能的影响 |
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徐党委1, 黄重1, 张可1,2,3, 魏宏宇2, 夏志升1, 杜海明1, 张明亚4
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(1.安阳钢铁集团有限责任公司,河南 安阳 455004; 2.安徽工业大学 冶金工程学院,安徽 马鞍山 243032;3.钢铁研究总院有限公司,北京 100081; 4.安徽工业大学 材料科学与工程学院,安徽 马鞍山 243032)
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| 摘要: |
| 采用Gleeble-3800热模拟试验机研究了Q550qENH钢粗晶热影响区(CGHAZ)在不同热输入下的热循环过程,结合OM、SEM、EBSD、Vickers硬度计和低温冲击试验等手段探讨了热输入对Q550qENH钢焊接热模拟CGHAZ组织和力学性能的影响。结果表明:Q550qENH钢CGHAZ组织主要为板条马氏体(LM)、板条贝氏体(LB)和粒状贝氏体(GB)。随着焊接热模拟的热输入增大,LM含量不断减少,LB和GB含量不断增多,组织逐渐粗化,由10 kJ/cm时的LM+LB+少量GB转变为80 kJ/cm时粗大的GB组织；CGHAZ的显微硬度随之不断降低,由10 kJ/cm时的338HV降低至80 kJ/cm时的236HV；CGHAZ的-40 ℃冲击功则在焊接热模拟的热输入为10~40 kJ/cm时保持在250~300 J,随后急剧降低至80 kJ/cm时的13 J,-40 ℃冲击断口处出现明显的河流状花样,呈脆性断裂形式。由焊接热模拟实验可知,Q550qENH桥梁钢的最佳焊接热输入区间在30 kJ/cm以下,此时CGHAZ在兼具高硬度的同时仍具有良好的低温韧性。 |
| 关键词: 焊接热输入 粗晶热影响区 显微组织 力学性能 冲击断口 |
| DOI：10.11951/j.issn.1005-0299.20240163 |
| 分类号:TG44 |
| 文献标识码:A |
| 基金项目:河南省博士后科研启动项目(202103098)；横向合作课题(RH2300004022)；安徽省高等学校科学研究项目(2023AH051090). |
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| Effect of heat input on microstructure and mechanical properties of CGHAZ in welding thermal simulation of Q550qENH steel |
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XU Dangwei1,HUANG Zhong1,ZHANG Ke1,2,3,WEI Hongyu2,XIA Zhisheng1,DU Haiming1,ZHANG Mingya4
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(1. Anyang Iron & Steel Group Co., Ltd., Anyang 455004,China; 2. School of Metallurgical Engineering, Anhui University of Technology, Ma’anshan 243032,China; 3. Department of Structural Steel, Central Iron and Steel Institute Co., Ltd., Beijing 100081, China; 4. School of Materials Science and Engineering, Anhui University of Technology, Ma’anshan 243032,China)
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| Abstract: |
| The thermal cycle of coarse-grain heat affected zone (CGHAZ) of Q550qENH steel under different heat inputs was studied by a Gleeble-3800 thermal simulation tester. The effects of heat input on the microstructure and mechanical properties of CGHAZ of Q550qENH steel were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), a Vickers hardness tester and low temperature impact test. The results show that the CGHAZ of Q550qENH steel primarily consists of lath martensite (LM), lath bainite (LB) and granular bainite (GB). As the heat input increases, the LM content decreases, while LB and GB contents increases, leading to a coarser microstructure. At a heat input of 10 kJ/cm, the CGHAZ consists of LM, LB, and a small amount of GB, whereas at 80 kJ/cm, the structure transforms into coarse GB. The microhardness of CGHAZ decreases from 338HV at 10 kJ/cm to 236HV at 80 kJ/cm. The impact energy of CGHAZ at -40 ℃ remains at 250-300 J for heat inputs between 10 and 40 kJ/cm but drops sharply to 13 J at 80 kJ/cm. The impact fracture at -40 ℃ shows an obvious river-like pattern, indicative of brittle fracture. According to the welding thermal simulation experiments, the optimal welding heat input range of Q550qENH bridge steel is below 30 kJ/cm, ensuring both good low temperature toughness and high hardness in the CGHAZ. |
| Key words: welding heat input coarse-grain heat affected zone microstructure mechanical properties impact fracture |
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