镀层薄板的MIG钎焊

镀锌是钢铁防腐的重要方法，但锌的熔点为420℃，挥发温度为906℃，不利于焊接，当电弧刚一接触到镀锌板就挥发了，锌挥发和氧化会导致气孔、未熔合及裂纹。因此，焊接镀锌板一定要减少热输入量，采用特殊的钎焊材料和性能优良的MIG焊机进行焊接，重点分析了适合该种工艺的焊接设备的各部分特点及性能要求。

The MIG soldering of coated steel sheet

The galvanization is one of the most important m ethod for steel anti-corrosion. But the melting point of zinc is about 420 ℃ a nd it's vaporating point is 906 ℃. Both of these are not good for welding bec ause zine galvanizing layer vaporates when the steel is struck by arc. Furthermo re, the zinc vaporating and oxydizing cause air bubble, incomplete fusion and cr ack. So the heat input should be kept low to weld galvanization steel sheet. In this paper the MIG welding machine is adopted with special soldering material, a nd the emphasis is put on the analysising of welding equipment for this technolo gy.