热输入对960MPa级高强钢粗晶区组织及性能的影响  

Influence of heat input on microstructures and mechanical properties of 960 MPa high strength steel coarse-grained zone

作　　者：刘政[1] 魏金山[1] 崔冰[1] 安同邦[1] 田志凌[1] 

机构地区：[1]钢铁研究总院焊接研究所,北京100081

出　　处：《钢铁》2016年第2期72-77,共6页Iron and Steel

基　　金：国家国际科技合作专项资助项目(2015DFA51460)

摘　　要：采用Gleebe-1500D试验机对960 MPa级高强钢热影响区粗晶区(CGHAZ)组织进行模拟,研究了该高强钢在不同冷却时间下的组织变化与冲击性能的关系。结果表明:该钢热模拟粗晶区在冷速较高时主要生成板条马氏体。冲击吸收功随θ_(8/5)的增大先增加后减小,当θ_(8/5)为20 s时,冲击韧性最佳达到149 J,组织主要为大角度交错的板条马氏体。随着冷速降低转变为贝氏体组织、M-A组元后,冲击性能严重降低,粗晶区发生明显软化。该钢适合小热输入焊接,以保证焊接热影响区粗晶区的性能。The microstructure of the coarse-grained heat-affected zone（CGHAZ） of 960 MPa high strength steel was simulated by Gleeb- 1500 D. The relationship between the variation of microstructure and the impact energy was discussed.The results show that lath martensite was mainly generated in the CGHAZ with high cooling rate during the thermal simulation. The impact absorbing energy along with the increase of θ_（8/5）firstly increased and then decreased. When θ_（8/5）was 20 s,the impact absorbing energy was 149 J with the best,and the main structure was crossed lath martensite with large angle.With the increased cooling rate,the structure transformed to bainite and M-A which had a highly reduced impact property and a obvious softening CGHAZ. The steel is suitable for low heat input to ensure the property of CGHAZ.

关 键 词：焊接热循环 冷却速率 粗晶区 力学性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]