Performance Enhancement in Borocarburized Low-Carbon Steel by Double Glow Plasma Surface Alloying

In this paper, the performance of low-carbon steel is enhanced after introducing a borocarburized diffusion layer via double glow plasma surface alloying technology. Due to the boron-carbon gradient structure of low-carbon steel, the protective coating exhibits an excellent wear and corrosion resistance. Interestingly, the borocarburized layer consists of a 64 mu m carburized layer and a 27 mu m boride layer, which plays an effective role in enhancing the microhardness of borocarburized low-carbon steel, exhibiting a 1440 Vickers hardness increase in the surface microhardness of low-carbon steel. The potentiodynamic polarization measurement and impedance measurement results indicate that the boride protective film can effectively prevent aggressive chloride ions from invading the substrate, which indicates an excellent property of corrosion resistance. This systematic study paves a promising way for the future application of hard coatings in severe environments.