Contribution to the quality improvement of manganese steel Z120 MC12

Abstract

Manganese steel, known by the name of its inventor, steel Hedfield is deemed by its high mechanical shock resistance, it is used in the field of crushing and grinding. This type of steel is obtained by adding manganese (Mn) between (12 & 18%) to get a metallographic structure austenitic. For a very good quality of the manufactured parts, and to prevent crack initiation intergranular generated by the presence of pre-cipitates or clusters of carbides in the areas near the grain boundary, it is necessary to conduct a treatment hyper thermal quenching at 1050°C to dissolve these clusters. On all treated samples, we find the presence of an austenitic structure with a homogeneous distribution of grains having a size to be correct [1]. However, it appears as a network, the presence of a network of black dots (as precipitates) we find abnormal, and which we know neither the nature nor its impact on the metallurgical quality of the material. To solve this problem, we con-ducted a specific analysis by scanning electron microscopy (SEM) to explain the nature of these blackheads and subsequently, tried to judge when its influence on the structure of austenitic manganese steel.