Transient Calculation of Flame Flow Characteristics and Parameters Analysis of Substrate Performance in High-Velocity Oxygen-Fuel Thermal Spraying

301 stainless steel is austenitic stainless steel with excellent service characteristics. To fully reveal the influence of the spraying process on its surface characteristics, a 3D HVOF thermal spraying model was established in this study. The transient evolution for flame flow was simulated during the spraying WC-12Co powder on the surface of 301 stainless-steel substrate, and the particle distribution at different locations in the calculation domain was captured. The effects of substrate shape, spraying angle and spraying distance on the substrate temperature, strain rate and shear stress were analyzed. The results show that the temperature distribution affects the strain rate and shear stress on the substrate surface. The more uniform the temperature distribution, the lower the strain rate and shear stress. For the cylinder substrate, the strain rate and shear stress of 60 degrees spraying angle are lower and concentrated on one side (upper part) of the substrate. The spraying direction should be selected from top to bottom, which can uniformly reduce the substrate surface stress and facilitate the high-quality coating formation.