保温时间对20G/316L异种金属TLP焊接接头组织及性能的影响  

Influence of holding time on microstructure and mechanical properties of 20G/316L dissimilar metal TLP welded joints

作　　者：唐景黎 李光文[1] 刘鑫慧 黄本生[1] Tang Jingli;Li Guangwen;Liu Xinhui;Huang Bensheng(Southwest Petroleum University, Chengdu 610500, China)

机构地区：[1]西南石油大学

出　　处：《焊接》2019年第7期26-30,I0023,共6页Welding & Joining

基　　金：国家级大学生创新创业训练计划(201810615045);校级大学生课外开放实验项目(KSZ17133)

摘　　要：以非晶态Ni箔为中间层材料,采用高频感应加热系统,对20G/316L进行了瞬间液相扩散(TLP)连接试验,研究了保温时间对接头界面组织、元素扩散迁移情况以及力学性能的影响。结果表明,在焊接温度为1 120 ℃,保温时间为30~60 min时,20G碳钢与316L不锈钢之间能实现较好的连接;在焊接过程中,不锈钢侧基体中有碳化物析出,且随着保温时间的延长,类奥氏体组织逐渐形成;在较短的保温时间里,中间层Ni元素优先向不锈钢侧扩散,形成一定宽度的扩散层;随着保温时间的增加,碳钢侧界面出现弯曲,界面元素互扩散通量增大;当保温时间增加至50 min时,界面元素扩散充分,细小的奥氏体组织重新生成,接头抗剪强度达到峰值(351 MPa)。The amorphous Ni foil was used as the intermediate layer material. The transient liquid phase diffusion (TLP) connection experiment was carried out on 20G/316L stainless steel by high frequency induction heating system. The microstructure, element diffusion and migration of the joint’s interface and the mechanical properties were studied. The results show that when the welding temperature is 1 120 ℃ and the holding time is 30~60 min, good metallurgical bonding can be achieved between 20G carbon steel and 316L stainless steel. During the welding process, carbides precipitated in the stainless steel side matrix. With the extension of holding time, the austenite-like structure is gradually formed. In a short holding time, the Ni element in the middle layer preferentially diffuses toward the stainless steel side to form a diffusion-dissolving layer of a certain width. As the holding time increases, carbon steel side interface appears bending and the interdiffusion flux of the interface element increases. When the holding time increases to 50 min, the interface element diffuses sufficiently, the fine austenite microstructure regenerates, and shear strength of the joint reaches a peak (351 MPa).

关 键 词：20G/316L 瞬间液相扩散 微观结构 元素扩散 

分 类 号：TG406[金属学及工艺—焊接]