Weldability of austenitic manganese steel

Hadfield’s manganese steel, nominally Fe–1.2%C–13%Mn, is an alloy of inherent toughness, work-hardening characteristics and excellent resistance to some types of adhesive and abrasive wear. However, due to its low yield strength, it may be deformed markedly before its work-hardening become effective. In certain applications, such as railroad crossings and rock-crushers, this can be a disadvantage. In practice, when this deformation becomes excessive, welding is employed to restore the casting to its original dimensions. During welding, precautions have to be taken to avoid overheating and the attendant carbide precipitation which may lead to subsequent early failure. Three different electrode compositions were used to overlay-weld austenitic manganese steel cast in the form of rail heads. Two of the electrodes were obtained commercially and the third was of novel chemical composition and was produced in our laboratory. Mechanical tests were then carried out to simulate the battering deformation likely to result from in-service exposure. The procedure highlighted the work-hardening characteristics and resistance to plastic flow of the weld deposit and base material, one of which consisted of the standard Hadfield’s alloy whilst two others had minor transition element additions. The electrode containing molybdenum produced a weld overlay which showed better work-hardening characteristics and deformation resistance than those of the other two commercial electrodes studied.