| 摘要 |
PURPOSE:To make a joining strength sufficient with preventing the formation of embrittled layer at a joining part by making a base metal and zirconium group clad material in a laminated body with overlapping by providing a gap between them so as not to come into contact directly and by subjecting to hot rolling after reducing the pressure of the gap to be vacuum eta1torr. CONSTITUTION:The clad material 2 having smaller size than that of base metal 1 is placed on it by pinching supporting rod 3, then side face frame material 4 is placed along the edge part of the four sides of the base metal 1 and the clad material 2 is surrounded by placing upper face frame piece 5 thereon further. The base metal 1, side face frame material 4 and upper face frame material 5 are then tack-welded and hermetically sealed by electron beam welding inside the vacuum chamber reduced to <=1torr. This tack-welded assembly material is taken out of the vacuum chamber to subject the tack-welded part to main welding and this assembly material is inputted into heating furnace as it is and after heating to the prescribed temp. the whole assembly material with frame materials is subjected to hot rolling by the specified rolling schedule and after removing the frame material after rolling the part to pinch the supporting rod 3 of both ends is cut. |
