| 摘要 |
A heating process makes a temperature of joining surfaces Wa and Ta of a pair of metal parts W and T at the start of a first joining process equal to 20% or greater, preferably, 40% or greater of a melting point of material of the metal parts W and T. The heating process makes a heating depth h of the pair of metal parts W and T at the start of the first joining process equal to 1.0 mm or greater. |
