Improvement of wear resistance of some cold working tool steels

Abstract There are two basic options for improvement of surfaces of heat treated tool steels for cold working: mechanical treatment such as burnishing, or else chemical modification such as nitriding. The latter is affected not only by the nature of the chemical agent but also by diffusivity of that agent through the steel. We focus first on the number and order of operations performed on the steel surfaces: turned+burnished (T+B), turned+nitrided (T+B) and turned+burnished+nitrided (T+B+N). We have investigated two tool steels, Sverker 21 (AISI D2) and Vanadis 6. The former belongs to traditional steels, the latter is classified as advanced powder metallurgy (P/M) alloyed steel. We have performed pin-on-disc tribological experiments to determine abrasive friction and wear. Our evaluation of tribological properties of these two cold working steels enables an improvement of their manufacturing procedures leading to significant wear reduction. The improvement proposed is applicable not only to tool steels but also for instance to titanium alloys.