摘要
基于某船舶舾装薄壁铝合金筒形构件易焊穿、成形一致性差的问题,采用自动脉冲交流钨极氩弧焊(TIG焊)工艺对直径245 mm、壁厚2.5 mm的5A06铝合金筒形件进行焊接工艺与组织性能研究。采用光学显微镜、显微硬度计、扫描电镜(SEM)等方法对接头组织进行研究,并综合显微硬度分布规律及元素分析,探究了接头各区域显微硬度变化的原因。结果表明:自动TIG焊适合于薄壁铝合金构件的焊接,在合理的参数范围内可以获得高质量的焊缝;焊缝组织为α-Al和β-Al3Mg2及少量的析出强化相,β-Al3Mg2呈点状或链状分布;接头软化现象与Mg元素的烧损有关,且烧损程度随距焊缝表面的距离增大而减小。
Based on the problems of the easy penetration and the poor forming consistency of the thin-walled aluminum alloy cylindrical workpieces in the ship outfitting,the welding technology and microstructure of 5A06 aluminum alloy tubular parts with a diameter of 245 mm and a wall thickness of 2.5 mm were studied by using the automatic pulse exchange tungsten argon arc welding(TIG welding)process.The microstructure of the joint was studied by means of the optical microscope,the microhardness tester and the scanning electron microscope(SEM).Based on the distribution of the microhardness and the element analysis,the reason of the microhardness change in each region of the joint was explored The results show that the automatic TIG welding is suitable for the welding of the thin-walled aluminum alloy workpieces and can obtain high quality welds within the reasonable parameters.The microstructure of the weld wasα-Al andβ-Al3Mg2 and a small amount of the precipitated strengthening phase,and the distribution ofβ-Al3Mg2 was dot or chain.The phenomenon of the joint softening is related to the burning loss of Mg element,which decreases with the increase of the distance from the weld surface.
作者
强伟
温斌和
马欢
李欢
QIANG Wei;WEN Binhe;MA Huan;LI Huan(College of Material Science and Engineering,Xi’an Shiyou University,Xi’an 710065,China;Xiamen King Long United Automotive industry Co.,Ltd.,Xiamen 361023,Fujian,China;Jinlong United Automobile Industry(Suzhou)Co.,Ltd.,Suzhou 215028,Jiangsu,China)
出处
《焊管》
2020年第3期14-18,共5页
Welded Pipe and Tube
基金
陕西省教育厅专项科研计划项目“微区电化学测试装置的研制与焊接接头腐蚀模型的研究”(项目编号18JK0615)。
关键词
焊接
铝合金
薄壁筒形件
脉冲TIG焊
微观组织
硬度分布
welding
aluminum alloy
thin-walled cylindrical workpieces
pulse TIG welding
microstructures
hardness distribution
