Multiflow Pressure Quenching in Vacuum Furnaces

Abstract

Abstract Vacuum heat treatment is an increasingly popular thermal processing technique which is now widely established practice in the aerospace, automotive and machine tool industries. This paper is concerned with the development of a pressure quenching system for vacuum furnaces which provides both the optimum metallurgical properties and minimal distortion of components during hardening. First introduced by Consarc in the mid-1980s the Multiflow system utilises multiple gas flow patterns to achieve uniform quenching conditions and hence minimise the distortion of component during hardening. This is in contrast to vacuum furnaces employing a conventional, single gas flow pattern which results in a less uniform quench. Since 1989 the ongoing development programme at Consarc Engineering Ltd, has resulted in further improvements to the Multiflow system. The latest generation of furnaces incorporates an improved design of heat exchanger which has significantly increased the cooling rate of the furnace. The improved heat exchanger is the by-product of extensive in-house testing and state-of-the-art computer aided design techniques. The latest multiflow furnaces therefore offer the capability to harden awider range of materials while maintaining the uniformity of the quench and the dimensional stability of components.