| 摘要 |
PURPOSE:To obtain a weld metal having excellent material quality by specifying the hardenability index of the weld metal and the index relating to the cooling time at the time of welding to specific values. CONSTITUTION:Steel plates which contain, by weight %, <=0.25% C, 0.1 to 0.7% Si, 0.2 to 2.0% Mn, <=0.035% P, and <=0.05% S, consist of the balance Fe and unavoidable impurities, and has the hardenability index Di expressed by equation 1 in ranging <=8 are welded by an electron beams. Alloy elements are added at the time of welding to adjust the hardenability index Di of the weld metal to >=3.0 and the index Ce relating to the cooling time at the time of welding expressed by equation II determined from the width of the weld metal to >=4 and <=55. The relation between Cs and Di of the weld metal exists in the range expressed by equation III, equation IV. In the equations, the respective components are weight % and W is the width cm of the weld metal. |
