激光熔敷Cr_3Si/Cr_2Ni_3Si金属硅化物涂层耐磨性与耐蚀性研究

Study on Wear and Corrosion Resistance of Laser Clad Cr_3Si/Cr_2Ni_3Si Composite Coatings on Austenitic Stainless Steel

以 Cr- Si- Ni预合金化粉末为原料 ,采用激光熔敷技术在 1Cr18Ni9Ti不锈钢表面制备出以金属硅化物 Cr3Si为增强相、以复杂多元金属硅化物 Cr2 Ni3Si为基体的快速凝固金属硅化物冶金涂层 ,在滑动磨损条件下评价了其耐磨性能 ,并采用阳极极化方法分别评价了该涂层在 0 .5 mol/L 的 H2 SO4 及 3.5 % Na Cl溶液中的电化学耐蚀性能 .结果表明 ,在滑动磨损条件下 ,所研制的涂层具有优异的耐磨性能 ,在 0 .5 mol/L的 H2 SO4 及 3.5 % Na Cl水溶液中具有优良的电化学耐蚀性能 ,这归因于其组成相 Cr3Si及 Cr2 Ni3Si的优异耐磨耐蚀性 ,以及非平衡快速凝固过程导致的组织细化、致密化和均匀化 .

Rapidly solidified wear and corrosion resistant Cr 3Si/Cr 2Ni 3Si metal silicide coatings were fabricated on an austenitic stainless steel 1Cr18Ni9Ti substrate by laser cladding, using Cr Si Ni elemental powder blends as the raw materials. The tribological behavior and corrosion resistance of the coatings were investigated by friction and wear test under ambient dry sliding and anodic polarization curves of the coatings in H 2SO 4 and NaCl solutions. The volume fraction of primary Cr 3Si dendrites has a remarkable influence on the hardness, wear and corrosion resistance of the coating. It is the rapidly solidified microstructural characteristics and the presence of a large amount of hard, wear and corrosion resistant Cr 3Si and Cr 2Ni 3Si that make the coating have excellent wear resistance under ambient dry sliding wear and excellent electrochemical corrosion resistance in 0.5 N H 2SO 4 and 3.5% NaCl aqueous solutions.