Abstract
For the purpose of lowering the thermal expansion coefficient of high manganese austenitic steel, the effects of carbon and manganese content on the thermal expansion coefficient from O to 100°C were investigated. The permeability after cold working and electrical resistivity were measured in these steels. These physical properties were also investigated after addition of various alloying element such as Si, Cu, Ni, Cr, Mo, Co, and Al in 0.25%C-25%Mn (or 21%Mn) based steel. The decrease of carbon content and the increase of manganese content markedly reduced the thermal expansion coefficient. The addition of ferrite forming elements did not result in increase of permeability, but electrical resistivity was markedly increased with addition of Si or Mo in 0.25%C-25%Mn steel. Particularly, the mechanism controlling the thermal expansion coefficient of high manganese austenitic steel is discussed by making reference to existing theories.
Hot ductility and strengthening due to controlled rolling in high manganese austenitic steel were studied to establish the optimum processing condition.
