A Study Of The Corrosion-wear Resisting Nano-particles Reinforced Ni Matrix Alloying Layer By Double Glow Plasma With Brush Plating Ni Interlayer

As a kind of extensively used Austenitic stainless steel, 316L has been widely used in the fields of petroleum, chemical industry, atomic energy, astronautics and so on. Though it has excellent corrosion resistance, its pitting corrosion and stress corrosion are poor and so is the hardness and wear resistance, which can't meet with the require of composite resistance of wear and corrosion. The resistance of wear and corrosion can be effectively improved by a nickel base alloy layer reinforced by nano particles prepared on the surface of 316L stainless steel.Various methods about surface engineering have been analyzed, and double glow plasma composite alloying technique is chosen to prepare the nickel base alloy reinforced by nano particles. The microstructure and phrases components of three kind of particles, Al2O3, SiO2 and SiC, reinforced nickel base alloy is investigated, then are the electrochemical tests in 3.5%NaCl solution and 5%HCl solution, dipping in 20% HCl solution for 100 hours, the wear test at room temperature to measure the friction coefficient and weight loss. The results about wear and corrosion are analyzed.The results show that: Al2O3 nano particles reinforced nickel base alloy mainly containsγ-Ni and AlNi3, the alloy layer is well connected with the substrate and contains two layer, the deposition layer and the diffusion layer and the elements are distributed in gradient. Al2O3 particles decomposed into AlNi3 at high temperature, the corrosion resistance is improved a little but still lower than the comparing materials, ie, Ni-Cr-Mo-Cu multi-elements alloying layer and high speed nickel composite alloying layer; its wear resistance is improved at certain extent and the hardness after wear test is evidently improved.The phrase of SiO2 nano particles reinforced nickel base alloy isγ-Ni, and there exists some amorphous, the wear and corrosion resistance both are better than the comparing materials, the substrate, the Ni-Cr-Mo-Cu multi-elements alloying layer and high speed nickel composite alloying layer.SiC nano particles reinforced composite alloying layer mainly containsγ-Ni phrase, and the particles decomposed and formed new phrases of Cr6.5Ni2.5Si, Cr3C2 and Cr23C6 at high temperature with the elements around them during the Ni-Cr-Mo-Cu multi-elements alloying process, which highly improved the wear resistance while decreased its corrosion resistance compared with the substrate 316L stainless steel and the Ni-Cr-Mo-Cu multi-elements alloying layer and high speed nickel composite alloying layer.After the compare of wear and corrosion behavior of the three kind of particles reinforced alloying layers, it is shown that SiO2 nano particles reinforced composite alloying layer owning the best integrated performance.