模拟焊接HAZ高温塑性功与再热裂纹敏感性

采用模拟焊接ＨＡＺ再热温度下缓慢恒速拉伸试验，测试研究了有再热裂纹倾向的１５ＣｒＭｏＶ和１８ＭｎＭｏＮｉＮｂ两种钢的焊后再热处理时力学性能的变化，发现存在一个塑性和塑性功低落的温度区间。而且随着再热温度下保温时间的延长，塑性和塑性功有所上升，塑性和塑性功低落的温度区间更趋明显。提出了采用再热温度下拉伸塑性功来评定再热裂纹敏感性的新概念。

Tensile plastic work done at high temperature and sensitivity to reheat cracking of simulated wela HAZ

The mechanical properties of simulated coarse grain heat affected zone(HAZ)in both steel 15ClMoV and Steel 18MnMoNiNb were investigated with slow tensile test at reheat temperature. There existed a temperature range in which the plasticity and the plastic work were the lowest. It was also found that if the specimen was kept at reheat temperature longer the plasticity and the plastic work would increase, and the temperature range became more apparent.A new conception of using tensile plastic work at reheat temperature for estimating the sensitivity to reheat cracking was put forward.