16MnD5钢板焊接件热影响区开裂原因分析

Cause Analysis on Heat Affected Zone Cracking of Weldments of 16MnD5 Steel

采用化学成分分析、低倍检验、金相检验、显微硬度测试等方法对16MnD5低合金高强度钢板焊接件热影响区开裂的原因进行了分析。结果表明:裂纹起始于热影响区粗晶区,裂纹以沿晶和穿晶混合方式扩展,为以残余应力和母材淬硬倾向为主因的冷裂纹。

Cause analysis was conducted on the heat affected zone（HAZ） cracking of a high strength low alloy 16MnD5 steel plate weldment by the methods of chemical compositions analysis,macroscopic examination,metallographic examination and microhardness test.The results show that the crack began from the coarse grain zone of the HAZ,and extended in the mixed manner of intergranular and transgranular.The crack was cold crack which was mainly caused by residual stress and the base metal＇s tendentiousness of harden quenching.