| 摘要 |
PROBLEM TO BE SOLVED: To provide a welded joint with which a base metal fracture can be observed by resistance welding of high tensile steel plates having base metal strength above 350 MPa. SOLUTION: Weld metal zones are so formed to have a chemical composition that the value Q calculated by equation 1 satisfies (TS×√t)min . The chemical composition of the weld metal zones preferably contain 0.001 to 0.3% C, 0.01 to 3% Mn and a proper amount of >=1 kind of the group consisting of Si, Ni, Cr, Mo, V, Ti, Nb, Cu, Al and B. Welding is performed by regulating the chemical composition of the base metals or interposing a metallic piece having an alloy content higher than an alloy content of the base materials between the base metals. Equation 1 Where, TS: the tensile strength of the base metals (MPa), t: the sheet-metal gage (mm), (TS×√t)min : the minimum value among TS×√t of the base metals. |
