GB620386A - Improvements in or relating to a method of and apparatus for heat treating cylindrical metal articles - Google Patents

Abstract

620,386. Hardening metals. BUDD INDUCTION HEATING, Inc. Sept. 29, 1942, No. 13675. Convention, date, Nov. 21, 1941. [Class 72] In the hardening of the surface of cylindrical metal articles, the surface is heated to the hardening temperature and quenching is effected by projecting a solid peripheral stream of quenching fluid uniformly at an angle of less than 45 degrees on to the heated surface and then confining the quenching fluid to axial flow in contact with the surface. As shown, applied to hardening the internal surface of a cylinder, a heating head H and a quenching head Q, in axial alignment, move, at the rate of one inch per second, relatively to the surface C,to be treated, the quenching fluid being led from a chamber 13 in a mandrel to a chamber 37 formed between the upper part 11 and lower part 12 of the quenching head and then ejected, at an angle of 25-45 degrees to the axis of the work, on to the heated surface. The fluid then flows away through an annular passage, which may be one inch in width, between the surface being treated and the surface 34 of the lower part 12. The fluid may be supplied to and maintained in the chamber 13 at a pressure of 60 lbs. per square inch. A dry inert gas may be supplied from the front of the heating head to prevent quench fluid from flowing towards the heating head. Specifications 580,976 and 620,389 are referred to.