摘要
TIG焊接焊缝质量高但其熔深小,生产率低。若在被焊工件表面涂敷一层特殊的活性剂,再进行TIG焊接,能够起到增大熔深的效果,即A-TIG焊。研究了三种不同活性剂对φ54 mm×8 mm厚的20#钢厚壁管TIG焊接的影响,研究发现:添加3号活性剂的接头外观质量最好,添加2号活性剂的次之,添加1号活性剂的最差;三种活性剂熔深均大于8 mm,熔深增加量均达到3.211 mm以上,而不添加活性剂的厚壁管则不能焊透。使用2号活性剂增加焊接熔深的效果最明显。20#钢管母材显微组织是铁素体和珠光体,接头热影响区组织相较于母材更粗大,焊缝区的晶粒进一步长大,在原奥氏体晶界处产生针状粗大的先共析铁素体,主要组织仍为珠光体和铁素体混合物。添加三种活性剂的焊缝组织无明显变化,获得的焊接接头拉伸试样均断裂在母材,焊缝强度均高于母材。
TIG welding common welding consumables produces high quality welds and beautiful weld shapes.However,when welding thicker plates and pipes,the welding penetration is small and the welding productivity is low.Coating a layer of special active agent on the surface of the workpiece to be welded for TIG welding can increase the penetration depth and reduce the penetration width,which is the so-called A-TIG welding.This paper studies the influence of three different active agents on the TIG welding of a 20#steel thick-walled pipe with a thickness of 54 mm×8 mm.The results showed that the appearance quality of the joint with No.3 active agent was the best,followed by No.2 active agent,and the worst with No.1 active agent.The penetration depths of the three active agents are all greater than 8 mm,and the penetration depth increases are all above 3.211 mm.Thick-walled pipes without active agent cannot be welded through.For the samples welded with No.2 active flux,the average width of the front side of the weld is 8.639 mm and the average width of the back side is 7.621 mm.The effect of increasing the penetration depth is the most obvious.The microstructure of 20#steel pipe base metal is ferrite and pearlite.The structure of the heat-affected zone of the joint is larger than that of the base metal,and the grains in the weld zone are further grown.At the austenite grain boundary,acicular coarse proeutectoid ferrite is produced,and the main structure is still a mixture of pearlite and ferrite,and a small amount of upper bainite and lath martensite.The tensile specimens with three active agents all fractured on the base material,and the weld strength was higher than that of the base material.
作者
李佳伟
陈炫如
黄泽
李佳萍
郝妮娜
许海峰
李笑
戴军
LI Jiawei;CHEN Xuanru;HUANG Ze;LI Jiaping;HAO Nina;XU Haifeng;LI Xiao;DAI Jun(School of Automotive Engineering,Changshu Institute of Technology,Changshu 215500,China;Jiangyin hydraulic oil pipe Co.,Ltd.,Jiangyin 214400,China)
出处
《电焊机》
2024年第1期107-113,共7页
Electric Welding Machine
基金
江苏省产学研合作项目(BY2021279)。
关键词
活性剂
TIG焊
熔深
显微组织
力学性能
active agent
TIG welding
penetration
microstructure
mechanical properties
