液压支架用Q960钢板焊接性  

Weldability of Q960 steel plate for hydraulic support

作　　者：姜英龙 陈戈 段青辰 郭枭[1] 魏超 徐玉君[1] Jiang Yinglong;Chen Ge;Duan Qingchen;Guo Xiao;Wei Chao;Xu Yujun(Harbin Welding Institute Limited Company,Harbin 150028,China;Zhengzhou Coal Mining Machinery Group Co.,Ltd.,Zhengzhou 450016,China)

机构地区：[1]中国机械总院集团哈尔滨焊接研究所有限公司,哈尔滨150028 [2]郑州煤矿机械集团股份有限公司,郑州450016

出　　处：《焊接》2024年第8期31-37,共7页Welding & Joining

摘　　要：【目的】该研究旨在通过理论和试验的手段综合分析液压支架用Q960钢板的焊接性,以确定其满足使用条件的预热温度。【方法】采用Gleeble 3800-GTC热模拟试验机对Q960钢板进行了焊接热模拟试验,分析了不同冷却速率下焊接热影响区组织转变,并绘制Q960钢的焊接SH-CCT曲线,通过理论计算、热影响区最高硬度试验和铁研试验,系统研究了Q960钢焊接性。【结果】Q960钢板的平衡临界温度A_(c1)为702℃,A_(c3)温度为895℃;在8~80℃/s范围内,冷却速率对硬度无显著影响,焊接热影响区的组织以马氏体为主,硬度稳定在400~410 HV之间;Q960钢碳当量C_(E)为0.621%,C_(EV)为0.584%,P_(cm)为0.305%;焊接热输入为10.7 kJ/cm时,预热温度在150℃以下对热影响区最高硬度无显著影响;预热温度在80℃以上时,铁研试验未产生裂纹。【结论】Q960高强钢具有明显的冷裂纹倾向,焊前预热至80℃以上时可有效避免焊接冷裂纹的产生。[Objective]The purpose of this study was to comprehensively analyze weldability of Q960 steel plate used for hydraulic support through theoretical and experimental means to determine preheating temperature that met service conditions.[Methods]Welding thermal simulation test of Q960 steel was carried out by Gleeble 3800-GTC thermal simulation tester,microstructure transformation of welding heat affected zone was analyzed under different cooling rates,and welding SH-CCT curve of Q960 steel was drawn.Through theoretical calculation,maximum hardness test of heat affected zone and Tekken test,weldability of Q960 steel was systematically studied.[Results]Equilibrium critical temperature A_(c1) of Q960 steel plate was 702℃,and A_(c3) temperature was 895℃.In the range of 8~80℃/s,cooling rate had no significant effect on hardness.Microstructure of welding heat affected zone was mainly martensite,and hardness was stable between 400~410 HV.Carbon equivalent C_(E) of Q960 steel was 0.621%,C_(EV) was 0.584%,and P_(cm) was 0.305%.When welding heat input was 10.7 kJ/cm,preheating temperature below 150℃had no significant effect on maximum hardness of heat affected zone.When preheating temperature was above 80℃,no crack was produced in Tekken test.[Conclusion]Q960 high strength steel had obvious tendency of cold cracking sensitivity.When it was preheated to more than 80℃before welding,cold cracking could be effectively avoided.

关 键 词：焊接性 冷裂纹 预热温度 高强钢 

分 类 号：TG442[金属学及工艺—焊接]