| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of joining for a liquid-phase diffusion joining joint, by which the toughness and the proof strength of a joint including the heat-affected zone of a metallic material are improved. SOLUTION: In the method of the liquid-phase diffusion joining for the joint having the high proof strength and the high toughness one or more insert metals for the liquid-phase diffusion joining substantially 50% of which is amorphous is inserted between butts groove parts of materials to be joined, heated up to a temperature of the melting point of the inserted metal or higher, the materials to be joined are joined together by the liquid-phase diffusion joining by an isothermal solidification phenomenon based on a diffusion rate controlling of atoms, and the liquid-phase diffusion joining joint is formed. The subsequent cooling after the isothermal solidification of the liquid-phase diffusion joining joint is performed in a way that the cooling is so controlled that the cooling speed is equal to or higher than the value calculated by the following equation (1) expressed by major chemical components of the material to be joined, V( deg.C/S)=3/(9×%C+1.5×%Si+0.3×%Mn+2×%Cr+0.5×%Mo+4×%N) (1), until the temperature of the liquid-phase diffusion joining joint becomes 200 deg.C or lower. |
