| 摘要 |
PURPOSE:To prevent high temp. cracking that arises during welding in the stage of welding steel materials contg. <=0.06% C by using welding materials of such contents of C of which the entire content of C satisfies specific equations. CONSTITUTION:In the stage of welding steel materials contg. 0.005-0.06% C, welding materials contg. C in such a range wherein the entire content of C to be added from the welding materials satisfies the equationI[W: concn. of C in a welding wire (%), C: concn. of C in a filler metal (%), Y: addition ratio of filler metal to weld metal] are used. Here, the target steel is steels of >=0.005% C that can assure necessary strength at <=0.06% C, and stainless steels contg. gamma former elements such as Ni are excluded. The Y of the equationIis determined by the melting speeds (Ws, Bs) of wires and base materials, and the addition speed ys of filler metal and is expressed by the equation II. In a range of ordinary welding conditions, the ratio of the wire occupying in Ws+Bs is around 0.6 and the fluctuations thereof are small. Therefore if the Ws is known, Ws+Bs is determined, and if the Y is set suitably, the required y2 is known. |
