High Temperature Treatment of Castings from Steel Grade 150KhNM

Abstract

Abstract High-temperature processing of steel cast is an effective way to obtain a high range of properties of finish product. The main purpose of the study was to determine the critical temperatures and modes of processing of molten steel 150KhNM. The thermal calculation was carried out according to the additivity rule. The holding time of the melt was determined experimentally. Laboratory melts were performed with varying temperatures of maximum heating of the melt above and below tcr. The optimal modes of high-temperature processing of the melt were determined by analyzing the structure of solid samples. The influence of high-temperature treatment on the structure and properties of castings from steel grade 150KhNM has been studied. The main processing parameters of this alloy have been determined. The dependences of the metal overheating influence on the castings mechanical properties improvement are obtained. Examples of improving the quality of products with using optimal modes of high-temperature processing are given. The investigated modes have showed that holding at a critical temperature leads to change in the type of casting-box (raw sand, dry sand, chill mold) and uniformity of distribution. This fact leads to a change in properties and a more homogeneous structure is formed.