A Study on Austempering a Hıgh Carbon Powder Metal Steel
Abstract
In this study, 1.5% by weight of natural
graphite powders were added to NC 100.24 pure iron powders to obtain plain high
carbon steel powder metallurgy specimens. After respectively uniaxial pressing
at room temperature, 100 °C and 200 °C and under 700 MPa pressing pressure, the
specimens were sintered in an atmospheric controlled furnace at 1150 ° C. The
spec,mens were then austenitized at 950 ° C for half an hour in a salt bath at
300 ° C for austempering heat treatment. The structure transformations after
the heat treatment were examined using optic microscope. Through pressing
processes at different temperatures, the effects of densification rate on the
hardness and bainitic transformation were investigated. It was seen that by
increasing the densitity of high carbon powder metal materials, the bainitic
structure transformation was improved and thus hardness value was effectively
increased.
Keywords
References
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