| 摘要 |
PURPOSE:To improve fatigue strength of a spot welding joint, by specifying the relation between a welding current and time, and between a temper current and time, in a method for executing temper electrification after spot welding electrification to high tension steel. CONSTITUTION:A high tension steel plate which contains 0.06-0.40pts.wt. C, and has 0.06-0.06% Ceq (carbon equivalent) shown by the expressionI, and >=35kg/mm.<2> tensile strength is subjected to spot welding electrification, and after that, spot welding is executed by temper electrification. In this case, a value (index) of the expression II by a temper electrification current It, a welding electrification current Io, a temper electrification time Tt and a welding electrification time To is set to 0.25-0.82. This value has a physical meaning showing a ratio of calorie by electrification, and fatigue strength can be improved beyond the limits of the condition for improving the conventional static strength. |
