焊接热输入对06CuNiCrMoNb钢HAZ组织与性能的影响

研究了热输入对06CuNiCrMoNb钢焊接热影响区不同部位组织和性能的影响,重点分析了粗晶区的韧性与组织之间的关系。结果表明,模拟焊接热影响区没有出现"软化"现象,但是当线能量大于30kJ/cm情况下,粗晶区低温韧性迅速下降。对粗晶区的分析显示,线能量17kJ/cm条件下贝氏体铁素体呈细小板条状,在板条间存在着残余奥氏体薄膜,随线能量的增大,块状的铁素体数量增多,并且出现不规则片状M+A组元。

Influence of Heat-input on HAZ Microstructures and Property of 06CuNiCrMoNb Steel

The influence of the heat-input on microstructures and property in regions of simulated welding heat-affected zone（HAZ） of 06CuNiCrMoNb steel were investigated and the relationship between the toughness of the coarse grain heat-affected zone（CGHAZ） and microstructures were discussed.The results show that the tensile strength of simulated HAZ dose not debase than that of mother metal,but the low-temperature impact toughness of the CGHAZ declines rapidly on condition of heat-input above 30kJ/cm.The TEM observation indicates the shape of bainite-ferrite is thin lathlike and there are residual austenite films between lath,while with the increase of heat-input,the quantity of block ferrite increases and M-A constituent appears in ferrite matrix.