Abstract: In order to study the distribution of residual stress of multi-track overlapping plasma cladding of Co-based alloy under different process parameters to control the residual stress, orthogonal experiment was designed and nine groups of single-layer multi-track Co-based plasma cladding samples with different process parameters were prepared by plasma cladding. Blind-hole method was used to measure the residual stress at the starting location, intermediate location and finish location of each sample, and the influence of working current, scanning speed and powder feeding rate on the residual stress was analyzed. The residual tensile stress was distributed in the surface of the samples. The residual stress of start location was lower than the finish location, the residual stress parallel to the overlapping path was lower than that parallel to the scanning path. The working current was the most significant influence factor on the residual stress. The greater the working current is, the greater the residual stress is. With the increase of the scanning speed, the residual stress becomes smaller. With the increase of the powder feeding rate, the residual stress increase and then decrease.

Key words: plasma cladding, residual stress, co-based alloy, multi-track overlapping, blind-hole method