12CrNi5MoV锻钢焊接热影响区组织与性能研究

Microstructure and Properties of Coarse Grain in Heat Affected Zone of 12CrNi5MoV Forged Steel

采用热模拟技术研究了12CrNi5MoV锻钢焊接热影响区粗晶区的组织与性能。结果表明,经历一次焊接热循环后,材料粗晶区的抗拉强度与原始态试样相比显著升高,而冲击韧性明显降低;冷却过程中冷却速度加快引起材料组织中孪晶马氏体与残余奥氏体含量的增加是其粗晶区力学性能变化的主要原因。

The microstructure and properties of coarse grain in heat affected zone ( CGHAZ) of 12CrNi5MoV forged steel were studied by using welding thermal simulation technology. The result show that after one welding thermal cycle, the tensile strength of CGHAZ significantly increased compared with that of the original sample, and the impact toughness significantly decreased. The mechanical change of CGHAZ was attributed to the increasing of twin martensite and retained austenite contents in the CGHAZ which resulted from the increasing of cooling rate.