METHOD OF BONDING STEEL MEMBERS, METHOD OF ENHANCING BONDING STRENGTH OF UNITED OBJECT COMPRISING STEEL MEMBERS, STEEL PRODUCT, AND DIE-CAST PRODUCT

摘要

A method of steel member bonding in which steel members made of a chromium-containing steel material are bonded to each other. The method of steel member bonding comprises in the following order: a united-object formation step (S10) in which two or more steel members are butted and heated to a first temperature while pressing them against each other under given pressure conditions to thereby form a united object; and a bonding strength enhancement step (S30) in which the united object is heated to a second temperature not lower than the critical temperature (A1) of the steel material and then gradually cooled to a third temperature not higher than 600°C under such conditions that the cooling from the critical temperature (A1) to 600°C takes 10 hours or longer. By the method of steel member bonding, even when steel members made of a chromium-containing steel material are bonded to each other to produce a united object, sufficiently high bonding strength can be obtained.