Abstract
The carburized case properties of some practical case hardening steels were studied under gas carburizing and direct quenching conditions. The results obtained are as follows: The case properties such as case hardness, micro structures, toughness and retained austenite contents could be improved by lowering carburizing temperature and controlling surface carbon content within nearly the eutectoid range. Although case hardenability varied over a wide range depending on the type of steel and carbon content, it rose to maximum at about 0.6% carbon in all alloy steels examined.
