Tribological and microstructural investigations of the influence of deep cryogenic treatment on the properties of PM S390 MC high speed steel

摘要

Advantages of applying deep cryogenic treatment (DCT) after the quenching of high speed steels are well documented in references. But still there are no fully established methods for testing wear resistance that would clearly distinguish the impact of DCT from the impact of other stages in the heat treatment process on the steel tribological properties. In search of solutions to this problem, the own abrasive and erosive wear tests were carried out on the samples made from PM S390 MC high speed steel quenched with three different austenitizing temperatures, with and without DCT prior to tempering. Erosive wear testing was conducted with jets directed to the tested surface at angles of entry of 90 or 30 degrees, which generated cases of impact erosion or abrasion erosion. Test results have shown an increased resistance to impact erosion on deep cryogenically treated samples, as opposed to the conventionally heat treated samples which have showed an increased resistance to abrasion erosion and pure abrasion, with a significant influence of austenitizing temperature.