模拟焊后热处理循环次数对A516Gr70钢板组织性能的影响

研究了秦皇岛首秦金属材料有限公司中低温压力容器用A516Gr70钢板经不同循环次数模拟焊后热处理后的组织、性能变化情况。结果表明：A516Gr70钢板随着模拟焊后热处理循环次数的增加，屈服强度、抗拉强度呈下降趋势；韧脆转变温度（VTE）往高温方向移动。模拟焊后热处理后钢板组织仍为铁素体+珠光体带状组织，但随着模拟焊后热处理循环次数的增加，铁素体晶粒尺寸增加，珠光体层片粗化，导致钢板屈服强度及抗拉强度呈下降趋势。

Effect of simulated PWHT cycle times on microstructure and properties of A516Gr70 plate

The changes of microstructure and properties of A516Gr70 plate were studied,which used for low and moderate temperature pressure vessel after simulated post weld heat treatment（PWHT） at different cycle times．The research indicate that the yield strength and tensile strength are decreasing with increasing simulated PWHT cycle times，ductile- brittle transition temperature (VTE) shift to high temperature.After simulated PWHT,the microstructure of plate is still ferrite pearlite banded structure.However,with the increasing of the cycle times of simulated PWHT,the grain size of ferrite increases,and the pearlite layer is thicker,which leads to the redution of yield strength and tensile strength of plate.