engleski

Effect of Heat Treatment on Tribological Properties of PM S390MC High-Speed Steel

ABSTRACT: Tools for chip-forming machining are affected by various wear mechanisms. Since high-speed steel is among the materials used for the manufacture of these tools, this research was aimed at investigating the effect of heat treatment on tribological properties of high speed steel. The PM S390 MC steel produced by powder metal forming was used for testing. Test samples made of this steel were heat treated by a common procedure and also by deep cryogenic treatment. The latter process included the parameters which had been determined in the previous research. In order to investigate the effect of nitriding, some test samples were nitrided. The microstructure and hardness of the samples were tested. The load scanning test was used to determine the resistance to adhesive wear (galling), the “ball-on-flat” method was used to determine the resistance to erosion (angle of incidence 30º – erodent Ottawa 50/70) and dry sliding wear resistance, and the Tafel extrapolation method to determine corrosion resistance. Results of testing by the “ball-on-flat” method showed an increased wear resistance of deep cryogenically treated samples in the conditions of dry abrasive wear. The testing of resistance to adhesive wear (galling) by means of the load scanning test showed that nitriding significantly improved wear resistance, while deep cryogenically treated samples exhibited slightly lower wear resistance.

deep cryogenic treatment; nitriding; high speed steel; galling; wear resistance

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