Influences of the Precooling Treatment in the Heat Affected Zone of the Welding in a Used Hadfield-Type Steel

Abstract

The effects of precooling on the structural conditions of the heat affected zone (HAZ) of high manganese and high carbon content steel were studied. The steel samples were welded, homogenized at 1100°C for 45 minutes, and quenched in water. These samples were precooled to temperatures of 0°, − 30°, and − 60°C. Carbides, microfissures, cracks, or fractures in grain boundary were not found after the welding process. In the case of the homogenized samples with and without any precooling treatment, voids and microvoids were found at the grain boundary. No variations were observed in form and size of voids and microvoids in all samples. A significant increase in the hardness of the grain and grain boundaries located next to the fusion line of the heat affected zone of the precooled steel samples was found in relation to the homogenized samples. X-ray diffraction was used to study the evolution of the crystalline quality of the homogenized and precooled samples. It was found that the lattice parameter decreased and the crystalline quality increased as a result of the precooled conditions and welding process.