焊后热处理对沉淀硬化不锈钢15-7Mo焊接接头组织性能的影响

研究了4种不同的焊后热处理工艺对半奥氏体沉淀硬化不锈钢15-7Mo焊接接头组织性能的影响.结果表明:焊接接头不进行热处理或时效热处理的焊接系数低于0.7,焊接接头进行调整+时效热处理后的焊接系数可达0.9,而对焊接接头进行固溶+调整+时效热处理后焊接系数接近1.接头不进行热处理或者是仅时效热处理时,薄弱区为熔合线靠近母材的区域,组织为奥氏体和少量的铁素体.进行调整+时效热处理或固溶+调整+时效热处理时,熔合线靠近母材侧的组织为板条马氏体、少量的铁素体和沉淀析出相,焊缝的组织为板条马氏体和沉淀析出相,薄弱区消失,焊接系数大幅度提高.

Effect of postweld heat treatment on microstructure and mechanical properties of PH 15-7Mo stainless steel weld joint

The effect of postweld heat treatment on microstructure and mechanical properties of PH 15-7Mo stainless steel weld joint was investigated. The results show that the weld factor varies with postweld heat treatment. The weld factor is less than 0??7 without postweld heat treatment or with aging treatment. The weld factor is up to 0??9 after transformation and aging treatment. The weld factor is close to 1 after solution, transformation and aging treatment. Without postweld heat treatment or with aging treatment, the minimum hardness area exists in the fusion line. The microstructure is composed of austenite and a small amount of ferrite on the former condition. After solution, transformation and aging treatment, the microstructure is composed of martensite, a small amount of ferrite and precipitation hardening phase. The minimum hardness area does not exist. Therefore, the weld factor is improved.