JOINTING METHOD FOR CAST IRON PART AND MILD STEEL PART

摘要

PURPOSE:To joint the titled parts without generating the weld defect, by laterally inserting the copper-alloy wire against the plasma arc, so as to generate the wire are across the wire and the electrode of the plasma torch, and by carrying out the spot welding on the joint portion with the molten metal. CONSTITUTION:The wire 5 is laterally inserted into the plasma arc 4 generating across the plasma torch 1, the cast iron part 2, and the mild steel part 3, for generating the wire arc across the wire 5 and the W electrode 7 connected to the welding DC power source 6; hereby, the spot welding is carried out at the overlapped portion of the cast iron part 2 and the mild steel part 3. For the wire 5 is employed the copper-alloy mainly constituted of copper. At the welding work, at first the plasma arc is transferred, and after that, the wire 5, whose power supply is previously synchronized, is fed for generating the wire arc, and then, the plasma arc is stopped. On the purpose to prevent such weld defects as the blowhole, cracking, etc, the molten metal of the wire 5 is overlaid while the cast iron part 2 and the mild steel part 3 are prevented to the utmost from melting.