Chrome-plated Steel And Plasma Arc Interface Strengthening Process

Plasma nontransfered arc is proposed as a new method to treat Chrome-coated PCrNi3MoA sample to increase the life of the material. The metallurgy microstructure and the composition distribution were respectively analyzed by the optical microscope, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The microhardness distribution along the direction perpendicular to the interface and the adhesion force of the Cr coating was measured. Wear resistance and the heat stability were also investigated. The conclusion could be drawn that the treatment of non-transferred plasma arc increased the inter-diffusion of chromium atom and iron atom across the interface, alloy interfusion layer between the coating and the matrix formed especially when the energy density of the plasma arc was higher. The heat affected zone formed in the matrix close to the interface and the phase transformed to martensite to form a rigidification layer. The heat stability of the treated samples was superior to the untreated sample. Especially with proper patameter, the micro-hardness distribution and the wear resistance were notably improved. With the synthesis of the effect of the plasma arc treatment on Chrome-coated PCrNi3MoA sample, the optimum property of the material could obtained with the optimum paramerters.