Effect of carbon content, sintering temperature, density, and cooling rateupon properties of prealloyed Fe-1 center dot 5Mo powder

Mixtures of prealloyed Fe-1.5Mo (Astaloy Mo) with and without additions of 0.5-1.2 wt-%C were prepared and their sintering, as well as their mechanica l, properties investigated under different process conditions. It was found that carbon content, sintering temperature, and cooling rate had marked ef fect on physical and mechanical properties. Sintered density decreased with increase in carbon content and sintering temperature. On the other hand, U TS, TRS, and hardness values improved with up to 0.8 wt-%C addition, sinter ing temperature, and cooling rate. Percentage elongation decreased with inc rease in carbon content and cooling rate, but was higher for specimens sint ered at higher temperatures. The as sintered microstructures consisted of e ither fine or coarse pearlite, upper or lower bainite, and their mixture de pending on the carbon content and cooling rate. The heat treated mechanical properties showed some improvement for the specimens containing 0.5 and 0. 8 wt-%C. It became evident that a variety of ternary low alloy steels consi sting of Fe + 1.5Mo + 0.5-0.8 wt-%C can be produced and used in the as sint ered or heat treated conditions for PM structural parts having good physica l and mechanical properties as well as high dimensional accuracy with accep table microstructures. PM/0890. (C) 2000 IoM Communications Ltd.