PROPERTIES OF SINTERED T15 AND T42 HIGH-SPEED STEELS

This investigation examines the liquid phase sintering of T15 and T42 grades of high speed steels (HSS) using water atomised prealloyed powd ers. Sintering temperature and atmosphere were selected as the variabl es. Results showed that the optimum sintering temperature for achievin g high density (greater-than-or-equal-to 98%) for vacuum sintered T15 was higher (1270-degrees-C), in comparison to that for the T42 grade ( 1230-degrees-C). For either grade of HSS, hydrogen sintering permitted a lower sintering temperature than vacuum sintering. The sintered T15 HSS showed higher hardness and lower transverse rupture strength comp ared to the T42 grade. Analysis of the phases observed in the heat tre ated HSS established the presence of MC and M6C type carbides. T42 gra de HSS exhibited a relatively longer tool life for continuous cutting of CK-45 steel, compared to the T15 grade.