T250马氏体时效钢激光焊接-时效处理接头的强韧性

发布时间：2019-06-21 01:04

【摘要】：对T250马氏体时效钢进行光纤激光焊接和时效处理,研究了焊前时效和焊后时效条件下接头的强韧性并分析了原因.结果表明,焊前时效处理接头的强韧性较差,抗拉强度为时效态母材的62%,静力韧度为28%;焊后时效处理的接头的强韧性较好,抗拉强度达到了时效态母材的98%,静力韧度达到了71%.焊缝区是影响焊接-时效处理接头强韧性的关键区域,焊缝中弥散析出的Ni3(Ti,Mo)颗粒相是焊后时效处理的接头强韧性优于焊前时效处理的接头的根本原因.Ni3(Ti,Mo)析出相对接头的抗拉强度和弹性变形阶段的静力韧度有利,对接头塑性变形阶段的静力韧度有双重影响.晶界逆转变奥氏体对接头的抗拉强度和弹性变形阶段的静力韧度影响不大,但对接头塑性变形阶段的静力韧度不利.
[Abstract]:The optical fiber laser welding and aging treatment of T250 maraging steel were carried out. the strength and toughness of the joint under the condition of pre-welding aging and post-welding aging were studied and the causes were analyzed. The results show that the strength and toughness of the joints treated by aging before welding are poor, the tensile strength is 62% of that of the aging base metal and the static toughness is 28%, and the strength and toughness of the joints treated by aging after welding are 98% and 71% of that of the aging base metal. The weld zone is the key area that affects the strength and toughness of the welding-aging joint. The Ni3 (Ti,Mo) particle phase dispersed in the weld is the fundamental reason why the strength and toughness of the joint treated by post-welding aging is better than that of the joint treated by aging before welding. The precipitation of Ni3 (Ti,Mo) is beneficial to the tensile strength of the joint and the static toughness of the elastic deformation stage, which has a double effect on the static toughness of the joint in the plastic deformation stage. The inverse transformation of Austenite at grain boundary has little effect on the tensile strength and static toughness of joints in elastic deformation stage, but it is disadvantageous to the static toughness of joints in plastic deformation stage.
【作者单位】：清华大学机械工程系激光加工研究中心;清华大学先进成形制造教育部重点实验室;钢铁研究总院特殊钢研究所;
【分类号】：TG407

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