焊后热处理对309L不锈钢焊缝金属性能的影响

摘要

研究焊后热处理(PWHT)对309L焊缝金属的力学性能及显微组织的影响.结果表明,焊后热处理的保温时间对309L焊缝金属的力学性能影响很大,特别是韧性和延性;随着焊后热处理的保温时间的增加,其显微组织中的σ相含量逐渐增加,铁素体的含量逐渐减少;本试验条件下,焊后热处理保温时间在24 h之内时,对309L熔敷金属的断后伸长率没有明显的影响.%The effects of post-weld heat treatment(PWHT) on the mechanical properties and microstructure in 309L weld metals were studied.The results show that:The heat preservation time of PWHT has great influence on the mechanical properties of 309L weld metals,especially for toughness and ductility;The content of σ phase in the microstructure increases with the increasing of the heat preservation time after heat treatment;Under this experiment condition,PWHT within 24 hours has no obvious effect on the elongation of the tensile test in 309L weld metals.