Combined ausextrusion and dynamic strain aging of a hot-work die steel

Abstract

An AISI H13 hot-work die steel was subjected to combined thermal and mechanical treatments, namely ausextrusion followed by dynamic strain aging. Process variables investigated include ausextrusion temperature, austenitizing temperature, amount of prestrain, straining temperature, and strain rate. The effect of variables on mechanical properties and microstructure was determined. After optimization of the process variables the steel had a 0·2% proof stress value of over 2700 MN/m², an increase of some 80% over that of conventionally heat-treated material. Mechanical instability was observed above the 0·2% proof stress level.