Archives of Foundry Engineering

Abstract

The paper deals with the possibility of the renovation of permanent steel molds for casting using electric arc welding technology. When casting liquid metal into permanent steel molds, there is chemical-thermo-mechanical wear of the surface of the mold cavity and the inlet system, which causes a deterioration of the surface quality and dimensional accuracy of the casting. For this reason, it is necessary to renovate the steel mold after a certain casting interval -mold life. In this case, the technology of manual electric arc welding with a coated electrode was used for the renovation. The welding renovation aims to increase the service life of the mold using carbide hardfacing welds, which after welding achieve high mechanical properties of the renovated mold parts. Two types of hardfacing coated electrodes were used for welding, namely the OK Weartrode 55HD electrode and the OK Weartrode 50T electrode. Macroscopic analysis, tribological tests as well as the measurement of the hardness of the welded layers were performed to evaluate the quality and the friction coefficients of the additional materials used. The properties of hardfacing welds were compared with the properties of the basic material of the high-alloy steel mold. The main advantage is in addition to increasing the durability and longevity of the mold, also reducing the cost of mold renovation compared to other renovation technologies.