Y2O3添加量对17-4PH钢表面Stellite 6+Y2O3激光熔覆层组织与性能的影响

The Effect ofY2O3 Content on the Microstructure and Properties of Stellite 6 +Y2O3 Laser Cladding Layers on the Surface of 17-4PH Steel

摘要:

本文通过改变Y2O3元素的量(0、0.3、0.6和0.9 wt%)制备了耐磨、耐腐蚀钴基Stellite 6合金。研究Y2O3添加量对熔覆Stellite 6试样的微观组织、显微硬度、耐磨损与耐腐蚀性能的影响规律。结果表明：Y2O3的添加使晶粒结构由粗壮的柱状晶转变成细小均匀的等轴晶,添加0.6 wt%Y2O3的试样平均晶粒尺寸为160.8 μm,与未添加Y2O3的试样相比,最大晶粒尺寸细化了66.3 %。此外Y2O3颗粒集中分散在Stellite 6合金试样的枝晶间区域,在枝晶颗粒前形成一层粒子层,并抑制颗粒的运动和溶质原子的扩散。0.6 wt% Y2O3添加的试样具有最高的显微硬度值,平均显微硬度为532 HV0.2,并且由于Y2O3颗粒之间的晶粒尺寸和距离最小,因此表现出最佳的耐磨损和耐腐蚀能力,与未添加Y2O3的式样相比,显微硬度最大增加22.6 %,磨损率最大降低72.2 %,腐蚀电位最大提高了25.6%,腐蚀电流最大降低了39.8%。

Abstract:

In this study, wear-resistant and corrosion-resistant cobalt-based Stellite 6 alloys were prepared by varying the Y2O3 content (0, 0.3, 0.6, and 0.9 wt%). The effects of Y2O3 addition on the microstructure, microhardness, wear resistance, and corrosion resistance of the laser-cladded Stellite 6 samples were investigated. The results indicate that the addition of Y2O3changes the grain structure from coarse columnar grains to fine, uniform equiaxed grains. The sample with 0.6 wt%of Y2O3exhibits an average grain size of 160.8 μm, representing a maximum grain refinement of 66.3% compared to the sample without of Y2O3 addition.Furthermore,of Y2O3particles are mainly dispersed in the interdendritic regions of the Stellite 6 alloy samples, forming a particle layer in front of the dendrite grains, which inhibits grain movement and solute atom diffusion.The sample with 0.6 wt% of Y2O3addition shows the highest microhardness, with an average value of 532 HV0.2. Due to the smallest grain size and spacing between of Y2O3 particles, it also demonstrates the best wear and corrosion resistance performance. Compared to the sample without of Y2O3addition, the maximum microhardness increases by 22.6%, the wear rate decreases by up to 72.2%, the corrosion potential increases by up to 25.6%, and the corrosion current density decreases by up to 39.8%.