Improvement of Microstructure and Mechanical Properties of Manganese Steels by Adding Boron Alloying Element

Improvement of the mechanical properties and microstructures of industrial parts can improve working conditions, working life and reduce rejection rates and consequent, improve environmental effects of industrial developments. In this paper, the effect of Boron content in chemical composition ofManganese steel on improvement of microstructure and mechanical properties of manganese steels has been investigated. This improvement can reduce the consumption and rejection rate of castings and consequent environmental protection. The microstructure was investigated using optical, SEM and FESEM microscopy. In addition, mechanical tests such as tensile test, hardness and impact tests were performed on the samples. Microscopic investigations showed the presence of 0.007% Boron prevents of formation carbides in grain boundaries and also reduces the carbide sizes and cause uniform distribution. In the presence of Boron, annealing solution heat treatment, improve the morphology of carbides and modified it to spherical shape. The results of the research show that by increasing 0.007% Boron, fine and spherical carbides will form in austenitic microstructure of manganese steel which increase the hardness, toughness, tensile strength and modify carbide distribution and morphology in both heat treated and non-heat treated conditions. This results can improve casting operation time and rejection rates of castings in wear conditions as an environmental friendly material.