稀土提高40Cr钢氮化层抗冲蚀磨损性能的研究

本文研究了在气体氮化渗剂中加入微量稀土元素对40Cr钢氮化层组织、韧性及抗冲蚀磨损性能的影响。试验结果表明稀土在氮化时被渗入到钢的表层起微合金化作用，改善了渗层组织。稀土氮化层的韧性和抗冲蚀磨损性能，较普通氮化层有明显提高。扫描电子显微镜对冲蚀磨损试样表面形貌观察发现，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；而稀土氮化层则为塑性变形形成的犁沟剥落。

Effect of Rare Earth Elements on the Erosion Resistance of Nitriding Layers of 40Cr Steel

Effect of micro-addition of rare earth elements in the nitriding gas on the microstructure,toughness and erosion resistance of nitriding layers for 40Cr steel has been investigated.The experimental results show that the rare earth elements,permeated into the nitriding layers during nirtriding process,can improve the microstructure of nitriding layers due to the microalloying effect.As a result,the toughness and erosion resistance of RE-nitriding layers are increased significantly,compared with that of conventional nitriding layers.Observation of the erosion specimen surface with scanning electron microsope reveals that the eroded feature of conventional nitriding layers is furrow-like peeling formed through plastic deformation,accompanied with initial cross crack and large grinding peelings.However,the eroded feature of RE-nitriding layers is only furrow-like peelings formed through plastical deformation.