The Effects of Mn on Mechanical and Metallurgical Properties of Welded Metal in Thermite Welding Process of St49 Rails

Thermite welding is a chemically reaction welding process. The weld joint is produced by pouring of superheated molten metal around the joint to be welded، applying with or without of pressure. the importance of mechanical properties and microstructure of thermite welded components، this paper studies the effects of Mn (it is one of the available choices to improve mechanical properties of steels microstructure) on mechanicaland metallurgical properties (hardness، impact resistance، tensile strength، elongation and wear resistance) of St49 steel in thermite welding process. The results show that with the increases of Mn in welded metal، tensile strength and impact resistance are increased but when the Mn content exceeds a certain level (% 2. 5)، the characteristic values ​​of the welded metal is reduced. Also، results show that with the increases of Mn wear resistance and the hardness of the welded metal were increased and the highest hardness in the railhead is 700 (Bhn) and in of rail web is 600 (Bhn).