Improvement of technology for repair of ore-bucket unloader metal structure working under cyclic loading

Abstract

ABSTRACT The basis of all machines and mechanisms of cranes is a metal structure, more often welded; therefore, the further operation of the machine is influenced by reliability and safety of operation of a metal structure. With the operation of such unique equipment as ore-grab loaders, the problem of ensuring trouble-free operation is becoming more acute and relevant every year. There are methods that increase the current density of the arc by compressing it during plasma welding, cutting, as well as injected into the coating of the electrodes of substances with high affinity for the electron. However, at repair welding, manual welding by an artificial electrode is most often applied. The research work was conducted on modernisation of the power supply to increase the depth of penetration during welding. The studies of changes in penetration depth on the same technological modes for a typical and upgraded power supply were performed. It was found that the penetration depth increases by more than 30% as a result of the final welding stresses, deformations, the risk of fatigue cracks decreases. After repairs with an upgraded power supply, there are no stress concentrators, reduced thermal impact zone and, as a result, reduced final welding stresses.