Vacuum heat treatment optimization for improved load carrying capacity and wear properties of surface engineered hot work tool steel

摘要

Tools and dies used in hot metal forming are exposed to very demanding contact conditions, including elevated temperatures, high contact pressures and abrasive flow of work material, which lead to different types of tool damage. However, the most critical ones are wear and fatigue fracture. As the focus shifts toward the use of new lightweight high-strength materials, also requirements on tool properties are becoming more demanding. This requires use of surface engineering techniques like nitriding and PACVD coating and proper balance between hardness and fracture toughness. Vacuum heat treatment allows the optimization of the tool steel microstructure, which may result in increased fracture toughness while maintaining or even increasing hardness, which enhances possibilities of using coated forming tools.