LAMINATION TYPE DAMPING STEEL PLATE FOR STOP WELDING AND ITS STOP WELDING AND JOINING METHOD

摘要

PURPOSE:To improve the flatness of the steel plate surface corresponding to the visible surface to be used after the spot welding by giving the difference in the yield strength and/or the plate thickness between upper and lower steel plates with thermoplastic resin between. CONSTITUTION:The damping steel plate 1 is formed to the structure where a thermoplastic resin layer 4 is inserted between the visible surface side steel plate 2 and the invisible surface side steel plate 3 with the different plate thickness and/or yield strength in order to give the damping property. In that case, one of the plate thickness and the yield strength at least of the visible surface side steel plate 2 is made larger than that of the invisible surface side steel plate 3. Accordingly, the strain resistance of the visible surface side steel plate 2 with respect to the pressuring force of an electrode of the spot welding is improved relatively and the invisible surface side steel plate 3 can be strained preferentially. As a result, the visible surface side steel plate 2 can not be strained by straining the invisible surface plate 3 and the flatness of the visible surface side steel plate 2 can be maintained.