| 摘要 |
PURPOSE:To manufacture the friction welded valve having the high temperature strength at least equal to or higher than base metal without generating rupture on a joining part and having high reliability in the joining part of the large diameter valve for a marine vessel. CONSTITUTION:The head part 12 of a Ni-base super-heat resistant alloy (Nimonic 80A, for instance) and a shaft part 14 of heat resistant steel are rotated relatively while being pressurized by the first pressurizing force P1>=4kgf/mm<2>, the joining part 16 is heated till an approaching allowance is made to >=5mm by frictional heat at that time, the rotation is stopped, then, the head part and the shaft part are pressurized by the second pressurizing force P2>=14kgf/ mm<2> (ratio Pa/P1 of the pressurizing force >=1.25) and these are fixed till the approaching allowance is made to >=2mm. |
