一种微合金高强钢焊接冷裂纹敏感性  

Cold cracking sensitivity of welding for a kind of low carbon micro-alloyed high strength steel

作　　者：蒋庆梅[1] 陈礼清[1] 许云波[1] 孙卫华[2] 胡淑娥[2] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,沈阳110819 [2]济南钢铁股份有限公司技术中心,济南250101

出　　处：《中国科技论文在线》2011年第2期103-108,130,共7页

基　　金：国家科技支撑计划资助项目(2007BAE51B07)

摘　　要：通过理论计算、焊接热影响区最高硬度试验以及斜Y形坡口焊接裂纹试验,研究了一种1 000 MPa级低碳微合金高强钢的焊接冷裂纹敏感性。结果表明:对于1 000 MPa级的低碳微合金高强钢,利用碳当量法和新的冷裂纹敏感指数Pcm计算公式仅能初步判定其冷裂敏感性;结合不同焊接线能量和预热温度的焊接热影响区(HAZ)最高硬度试验可以间接判断该类被焊钢材的淬硬倾向和冷裂敏感性;利用不同预热温度下的斜Y形坡口焊接裂纹试验可以评定该钢的冷裂纹倾向。基于斜Y形坡口焊接裂纹试验结果,通过理论计算还获得了不同焊接线能量与临界预热温度间的关系曲线,为制定合理的焊接工艺提供了快速、有效手段。The cold cracking sensitivity of welding for a kind of 1 000 MPa grade low carbon micro-alloyed high strength steel was studied by theoretical calculations, maximum hardness tests of the heat affected zone （HAZ） and oblique Y-groove cracking tests. The results indicate that the carbon equivalent method and the new formula of cold cracking sensitivity index Pcm can only preliminary identify the cold cracking sensitivity of the steel. Maximum hardness tests for HAZ at different welding heat inputs and preheating temperatures can be used to indirectly determine the hardening tendency and cold cracking sensitivity of the steel. Oblique Y-groove cracking tests at different preheating temperatures can be adopted to evaluate the cold cracking tendency. Based on the results of oblique Y-groove cracking tests, a curve of critical preheating temperature versus heat input is obtained by theoretic calculations and it provides a rapid and effective means to make an appropriate welding process.

关 键 词：焊接 高强钢 开裂 敏感性 预热 

分 类 号：TG457.11[金属学及工艺—焊接]