保护气对304N不锈钢K-TIG焊接头组织性能的影响  

Influence of shielding gas on microstructure and properties of K-TIG welded 304N stainless steel

作　　者：柳阳 王秋平 

机构地区：[1]太钢先进不锈钢材料国家重点实验室,太原030003

出　　处：《焊接》2017年第9期32-35,共4页Welding & Joining

摘　　要：使用小孔钨极氩弧焊(K-TIG,keyhole TIG)焊接设备对13.5 mm厚度304N不锈钢板材进行了焊接,不开坡口一道焊透成型。利用SEM,XRD,共聚焦显微镜,铁素体仪,显微硬度计分析了不同保护气体组成对焊缝化学成分、焊接接头各区域微观组织以及性能的影响。结果表明,相对于母材,当采用纯Ar作为保护气体时,焊缝N含量下降了18%,铁素体含量增加了20倍,焊缝中心的显微硬度下降了15%;当采用Ar+3%N2作为保护气体时,焊缝N含量增加了90%,铁素体含量下降了84%,甚至某些区域的铁素体含量为零,焊缝的显微硬度提高了14%以上。304 N stainless steel plate with 13. 5 mm in thickness was butt welded by K-TIG without groove. The chemical components,microstructures and properties of butt welded joint were studied by SEM,XRD,3 D measuring laser microscope,hardness tester. The experimental results indicate that the N-content in the weld metal reduces by 18%,the ferrite content of weld metal increases by 20 times,and the hardness of weld decreases by 15%,compared with that of base material when pure Ar gas is used as the shielding gas. The N-content in weld metal increases by 90%,the ferrite content of weld metal reduces by 84%,and the hardness of weld increases by 14% at least when the shielding gas is the mixture of Ar + 3% N_2.

关 键 词：含氮不锈钢 小孔钨极氩弧焊 铁素体含量 

分 类 号：TG444.74[金属学及工艺—焊接]