Cr12钢的稀土诱导离子渗氮工艺

对Cr12钢进行了稀土诱导离子溅射渗氮试验,利用显微硬度计测量了试样表面渗氮层的硬度与层深,结合XRD衍射仪分析了复合渗氮层的相组成,最后用摩擦试验机检测试样表面的摩擦磨损特性。结果表明,稀土能够影响Cr12钢离子溅射渗氮效果,且其效果随两者距离的增加而急剧下降。当稀土与Cr12钢试样距离小于25 mm时,试样表面硬度相对普通离子渗氮工艺明显减小,表面摩擦因数及磨损率略差,但其渗氮层深度却明显增加;当两者距离超过25 mm时,稀土诱导效果明显减弱,试样表面的硬度及摩擦因数与普通离子渗氮工艺基本相同,但磨损率明显增大。分析表明,稀土元素能增大试样表面氮离子的吸附能力且为其渗入提供路径优势,当两者距离过大时稀土离子吸附性减弱,诱导效果消失,同时也使试样表面产生晶格缺陷,降低了其表面抗磨损的能力。

Rare earth induced ion nitriding process of Cr12 steel

Rare earth induced ion nitriding test was carried out on Cr12 steel. The hardness and depth of the nitrided layer on the specimen surface were measured by microhardness tester, and the phases of the nitrided layer were analyzed by means of XRD. Finally, the friction and wear characteristics of the specimen surface were quantified by friction testing machine. The results indicate that rare earth can affect the effect of ion sputtering nitriding on the Cr12 steel, and the effect decreases sharply with the increase of the distance between them. When the distance is less than 25 mm, the surface hardness of the specimen is obviously lower than that of the ordinary ion nitriding, and the surface friction coefficient and wear rate are also slightly worse, but the thickness of nitriding layer is significantly increased. When the distance exceeds 25 mm, the induction effect of rare earth declines significantly, but the hardness and frictional coefficient of the specimen surface are basically the same as those of ordinary ion nitriding. Meanwhile, the wear rate is obviously increased. The analysis shows that rare earth elements can increase the adsorption capacity of nitrogen ions on the specimen surface and provide path advantages for their infiltration. When the distance between them is too large, rare earth ions are not easy to be adsorbed on the specimen surface, and the rare earth induction effect is disappeared. Meantime, it also causes lattice defects on the surface of the specimen, which reduces the wear resistance of the surface.