抄録
In order to develop a series of austenitic manganese nonmagnetic steels, a systematic investigation has been made on the effects of chemical compositions including impurities and also heat treatments on the magnetic permeabilities, mechanical properties, machinabilities, and weldabilities.
The magnetic permeability depends on the austenite stability, that of strained specimen was expressed as linear function of Md temperature and the increase due to isothermal austenite decomposition was found to be suppressed by vanadium addition. A linear regression equation relating 0.2% proof stress to chemical composition indicated a great strengthening effect of vanadium comparable to that of carbon. Isothermal decomposition of austenite also lowers the Charpy impact toughness. It was found that the 0.7C-15Mn-1Ni steel was the optimum base composition. A modified grade of the base steel to possess both improved machinabilities and weldabilities was developed by lowering the phosphorus level and also adding free-machining elements as calcium and sulfur.
