THE INFLUENCE OF Ni AND Cr-CONTENT ON MECHANICAL PROPERTIES OF HADFIELD'S STEEL

In the year 1882 Robert Hadfield discovered Manganese steel which was hardened by quenching it in water from a temperature of a thousand degree centigrade. The hard steel was to be used in the manufacture of tram wheels. The first World War provided new markets for manganese steel, spur armour plate and shells, tank treads and soldier's helmets. By 1919 Hadfields were Sheffield's biggest employers and was probably the largest specialist alloy steel manufacturer in the country. The original austenitic manganese steel, containing about 1,2% C and 12% Mn. Hadfield's steel is unique in that it combines high toughness and ductility with high work-hardening capacity and, usually, good resistance to wear. Consequently, it rapidly gained acceptance as a very useful engineering material. Hadfield's austenitic manganese steel is still used extensively with minor modifications in composition and heat treatment, primarily in the fields of earthmoving, mining, quarrying, oil well drilling, steelmaking, railroading, dredging, lumbering, and in the manufacture of cement and clay products. Austenitic manganese steel is in equipment for handling and processing earthen materials. Other applications include fragmentizer hammers and grates for automobile recycling and military applications such as tank track pads. The goal of this paper is an evaluation of influence of chemical composition on quality of Hadfield's steel, that was used by production of casting "points". In this case under term quality we can understand first of all the steel toughness which was evaluated by impact test and to a certain degree by tension test.