| 摘要 |
PROBLEM TO BE SOLVED: To provide a spot laser composite weld joint which is excellent in joint rigidity even if the weld joint is formed of lapped steel plates, including a high-rigidity steel plate, which are applied with spot laser composite welding.SOLUTION: A spot laser composite weld joint is a lapped weld joint which is formed of two pieces of steel plates 1, 2 whose plate thicknesses are t, t. At least one of the two pieces is a high-rigidity steel plate whose tensile strength is not lower than 590 MPa. In the spot laser composite weld joint, two or more spot weld parts 3, ..., 3 are arranged, a weld area not smaller than 2 mmin total is arranged between the adjacent two spot weld parts 3, 3, one or two or more laser weld parts 4 having weld-in depths hnot smaller than 80% of the total plate thickness (t+t) of the two pieces of the steel plates are arranged, nugget diameters dof the two or more spot weld parts 3, ..., 3 are not smaller than 4√[(t+t)/2] (units of the nugget diameters, t, and tare mm), and a clearance 5 between the two pieces of the steel plates 1, 2 at the outside of a corona bonded part 32 of the two or more spot weld parts 3, ..., 3 is not larger than 0.2 mm. |
