摘要
采用超声表面滚压(Ultrasonic surface rolling extrusion,USRE)加工方法对调质态40Cr轴进行处理。通过对处理表层进行微观结构观察发现:该加工方法既可以使表层纳米晶粒细化至3～7nm,还可以使表面粗糙度水平降至0.05μm;USRE样品表面附近区域形成了厚度约为200μm的流变组织,且晶粒尺寸沿厚度方向呈现梯度分布。力学性能测试证明:USRE试件表面显微硬度提高了63%,表面残余应力最高为-846MPa,压缩应力层深度可达1mm以上。摩擦磨损对比试验表明:USRE方法能够降低金属表面摩擦因数,提高其抗磨损性能。
Ultrasonic surface rolling extrusion （USRE） processing is applied on quenched and tempered 40Cr. Microstructure observations of USRE specimen surfaces indicate that the processing can both get nano-structured layers, with grain size of 3-7 nm, and reduce the surface roughness to 0.05 μm; plastic flow is formed from top surface to about 200 μm deep with graded distribution of grain size. Tests of mechanical properties show that microhardness of USRE specimen surface is increased by 63%; residual stress at the top surface can reach to -846 MPa and depth of residual stress layer is more than 1 mm. It has been determined by contrast wear test that USRE can reduce friction coefficient and improve the wear-resistant property.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第5期177-183,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金(50875184)
教育部新世纪优秀人才计划资助项目
关键词
超声表面滚压加工
40Cr
微观结构
纳米晶粒
力学性能
Ultrasonic surface rolling extrusion processing 40Cr Microstructure Nano-crystal Line Mechanical properties
