稀土对38CrMoAl钢软氮化层抗冲蚀磨损性能的影响

Effect of Rare Earth Elements on Erosion Resistance of Nitrocarburizing Layers of 38CrMoAl Steel

研究了稀土元素对38CrMoAl钢软氮化层抗冲蚀磨损性能的影响。结果表明:与软氮化相比,稀土软氮化提高了38CrMoAl钢的抗冲蚀磨损性能,同时提高了软氮化层的硬度以及钢的冲击韧度。由于软氮化时稀土的渗入,改善了渗层组织,从而提高了38CrMoAl钢的抗冲蚀磨损性能和机械性能。扫描电子显微镜对冲蚀磨损试样表面形貌的观察发现,普通软氮化层的磨损特征为塑性变形形成的犁沟剥落,并伴随着萌生横向裂纹,有大块磨屑剥落;而稀土软氮化层则为塑性变形形成的犁沟剥落。

An investigation of the effect of rare earth elements (RE) on erosion resistance of nitrocarburized 38CrMoAl steel was carried out by using an erosion test rig in an aqueous slurry of quartz particles. Results indicate that a significant improvement occurs in erosion resistance of nitrocarburized 38CrMoAl steel by introducing RE in nitrocarburizing processes comparing conventional nitrocarburizing processes. Measurement of mechanical properties exhibits that both hardness and impact toughness of nitrocarburized 38CrMoAl steel increase by using RE in nitrocarburizing processes comparing with the conventional processes. RE provide an improvement in erosion resistance. Scanning electron microscopy reveales that the furrow-like peeling from plastic deformation of material is predominant erosion mechanism of RE nitrocarburizied 38CrMoAl steel, while the furrow-like peeling with initial cross crack and large grinding peelings takes place predominantly in tests of conventionally- nitrocarburized ones, which results in a significant difference in erosion resistance.