CORRELATION OF MICROSTRUCTURE WITH HARDNESS, WEAR RESISTANCE, AND CORROSION RESISTANCE OF POWDER-INJECTION-MOLDED SPECIMENS OF FE-ALLOY POWDERS

Abstract

In this study, the powder injection molding (PIM) process was applied to Fe-alloy powders. Microstructure, hardness, wear resistance, and corrosion resistance of the PIM specimens were analyzed and compared with those of a conventional stainless steel, SS316L. When Fe-alloy powders were injection molded and then sintered at 1200 A degrees C or 1250 A degrees C, completely densified specimens with almost no pores were obtained. They contained 63 to 80 vol pct of hard (Cr,Fe)(2)B dispersed in the austenite or martensite matrix. Since these (Cr,Fe)(2)B borides were very hard, thermally stable, and corrosion resistant, hardness, high-temperature hardness, wear resistance, and corrosion resistance of the PIM specimens of Fe-alloy powders were 2 to 5 times as high as those of the stainless steel. Such property improvement suggested new applicability of the PIM products of Fe-alloy powders to structures and parts requiring excellent mechanical properties.