【作者】 蒋勇；

【导师】 王克鸿； 张德库；

【作者基本信息】 南京理工大学 ， 材料加工工程， 2012， 硕士

【摘要】 本文以Q235钢螺柱和6061铝合金板材为研究对象,分别采用高频感应熔钎焊和CMT熔钎焊的焊接方法进行了铝钢异种金属连接的探索性试验,得到了合理的焊接规范和良好性能的焊接接头,讨论了焊接工艺参数对焊缝成形、力学性能等的关系。结合对铝钢焊接性的讨论与分析,研究钢螺柱铝板钎焊焊接机理。高频感应熔钎焊时,采用Al-Si钎料。当感应焊接时间150s,感应电流为900A时,焊缝成形美观,能够得到良好的焊接接头,具有一定的力学性能；CMT熔钎焊时,采用热镀锌作为中间层。当焊接电流为210A,弧长修正率为10%时,能够得到良好的焊接接头。力学性能测试表明：通过高频感应熔钎焊技术、CMT熔钎焊技术对钢螺柱和铝板进行焊接。高频感应钎焊时得到的焊接接头的剪切强度达到65.32MPa；采用CMT钎焊技术得到的焊接接头的剪切强度最高达到76.34MPa。利用金相显微镜、SEM、EDAX手段对焊接接头显微组织进行观察和分析。结果表明,感应钎焊时,接头组织由金属间化合物Fe2Al5和FeAl3、Al-Si共晶相、α-A1固溶体三个区域组成。金属间化合物厚度为10μm左右,其厚度主要与Fe原子的扩散有关。随着焊接时间的增加或感应电流的加大,Fe的扩散就会越严重,形成的金属间化合物就会越厚；CMT钎焊时,在无镀锌钢螺柱与铝板焊接时,在铝钢结合处生成了厚度为20μm的金属间化合物,金属间化合物的主要成分为Fe2Al5和FeAl3;镀锌钢螺柱与铝板焊接时,由于Fe原子和Al原子的扩散作用,在镀锌层中间生成了少量的金属间化合物,对接头性能有一定的影响。更多还原

【Abstract】 In this paper, weldability of dissimilar metal between Q235 steel stud and 6061 aluminum alloy was researched through high-frequency induction welding-brazing and CMT welding-brazing. The right welding norms and good performance of weld joints were got respectively. Welding process parameters were discussed for welding performance and mechanical properties. Combined with the discussion and analysis of aluminum and steel welding, welding-brazing mechanism of steel stud and aluminum sheet were researched.When high-frequency induction welding-brazing, Al-Si solder was used. When the induction welding time 150s, the induced current 900A, weld appearance was good. A good welding joint, which has a certain mechanical properties, could be got; When CMT welding-brazing, hot-dip galvanizing is used as a middle-tier. When the welding current to 210A and the arc-length correction rate at 10%, a good welding joint could be got.The mechanical performance testing showed that:By means of high frequency induction welding-brazing technology and CMT welding-brazing technology for steel stud and aluminum welding, the shear strength of high-frequency induction welding-brazing joints reached 65.32MPa; The shear strength of CMT welding-brazing welded joints was up to 76.34MPa.Means of metallographic microscope, SEM, ED AX were used to observe and analysis the microstructure of weld joints. The results show that, through induction welding-brazing, the joint organization is composed by three regions, such as the intermetallic compounds of Fe2Al5 and FeA3, Al-Si eutectic phase,α-Al solid solution. The thickness of Intermetallic compounds is about 10μm, which is primarily associated with the spread of Fe atom. With the increase of welding time or the induced current, the diffusion of Fe will be more serious, the formation of intermetallic compounds will be thicker. When the steel stud and aluminum are welded by CMT welding-brazing, intermetallic compounds which has the thickness of 20μm is generated between the aluminum and steel. The intermetallic compound mainly composed of Fe2Al5 and FeAl3; when galvanized steel stud and aluminum are welded, due to the diffusion of Fe atoms and Al atoms, small amount of intermetallic compounds generate in the middle of galvanized layer. The intermetallic compounds have a certain impact on the performance of the joints.更多还原