Verfahren zum Herstellen eines reibungsverschweissten Ventils

摘要

A head portion of a nickel-based alloy, containing 0.20% or less of carbon, 18 to 30% of chromium, 0.5 to 2.5% of aluminum, and 1.0 to 3.0% of titanium, all by weight, as essential components, and a stem portion (solid body or pipe with wall-thickness-to-outside-diameter ratio of 0.1 to 0.3) of a heat-resisting steel, containing 0.5% or less of carbon and 10 to 30% of chromium, both by weight, as essential components and having an outside diameter of 40 mm or more, are relatively rotated under a first pressure P1 of 4 kgf/mm<2> or more, a joint portion is heated by means of frictional heat generated by the rotation so that the margin for plastic conversion becomes 5 mm or more for the case of the solid stem portion or 3 mm or more for the case of the pipe-shaped stem portion, the relative rotation is stopped, and the head portion and the stem portion are upset by means of a second pressure P2 of 14 kgf/mm<2> or more and with the ratio P2/P1 of 1.25 or more for the case of the solid stem portion or by means of a second pressure P2 of 10 kgf/mm<2> or more and with the ratio P2/P1 of 1.10 or more for the case of the pipe-shaped stem portion.