| 摘要 |
PURPOSE:To subject base metals such as special steels to MIG welding without causing lack of penetration by welding the base metals by MIG welding with an argon gas as inert gas by the use of a throttling nozzle while heating the base metals. CONSTITUTION:The weld zones of the groove 2 formed to base metals 1 of special steels such as 9% Ni steel are heated by using a TIG-welding nozzle 3 disposed as a preceding nozzle. On the other hand, with an argon gas as inert gas, the weld zone heated by the nozzle 3 is welded by using an MIG-welding nozzle 4 which is disposed as a succeeding nozzle by leaving a space from said nozzle 3 and is throttled at the end. With this method, sufficient penetration is obtained and good welding is performed even if the special steels are MIG-welded by using the high-purity argon gas. |
