Research of precise pulse plasma arc powder welding technology of thin walled inner hole parts

The inner hole parts played an oriented or supporting role in engineering machinery and equipment, which are prone to appear surface damages such as wear, strain and corrosion. The precise pulse plasma arc powder welding method is used for surface damage repairing of inner hole parts in this paper. The working principle and process of the technology are illustrated, and the microstructure and property of repairing layer by precise pulse plasma powder welding and CO2 gas shielded welding are tested and observed by microscope, micro hardness tester and X ray residual stress tester etc. Results showed that the substrate deformation of thin walled inner hole parts samples by precise pulse plasma powder welding is relatively small. The repair layer and substrate is metallurgical bonding, the transition zones (including fusion zone and heat affected zone) are relatively narrow and the welding quality is good. It showed that the thin walled inner hole parts can be repaired by this technology and equipment.