Improved fracture toughness, load carrying capacity and wear properties of hot work tool steel through optimized heat treatment

摘要

Tools and dies used in hot metal forming are exposed to very demanding contact conditions, which lead to different types of tool damage. However, for forming of new light-weight high-strength materials the most critical ones are wear and fatigue fracture, requiring use of surface engineering techniques and proper balance between hardness and fracture toughness. This is greatly escalated when thinking about coated forming tools. The aim of this work was to investigate the effect of austenitizing and tempering temperature on properties of AISI H11 hot work tool steel, including fracture toughness, wear resistance and load-carrying capacity. Results show that optimal vacuum heat treatment mainly depends on the properties required. In terms of load-carrying capacity and coating support high core hardness is of primary importance followed by sufficient fracture toughness level. However, for tool steel wear resistance good fracture toughness prevails over the ultimate core hardness.