双程切入磨削表面硬化层的研究

采用缓进给磨削方式和不同的磨削行程对40Cr钢进行了磨削淬硬，对单程和双程磨削表面硬化层的组织与性能进行了比较。结果表明，尽管单程和双程磨削时的原始组织不同，但两者的表面硬化层组织及其变化趋势完全相同。双程磨削淬硬可使表面硬化层深度及其均匀性、显微硬度及耐磨性得到进一步提高；但其最大残余压应力值及应力影响深度有所降低。双程磨削硬化层组织的形成机制同样适用于多程磨削淬硬或淬硬钢的磨削淬硬等场合。

Research on surface hardened layer by two-passes plunge grinding

The grind-hardening of 40Cr steel was performed with creep feed grinding mode and different grinding pass. The microstructure and properties of the hardened layer were compared. The results show that there are similar martensitic structures and similar microstructure changing trend in the surface hardened layer, though initial structures are different during one-pass grinding and two-passes grinding. The depths and its uniformity of the surface hardened layer,its microhardness and wear resistance are further improved under two-passes grinding. But its maximum compressive residual stress and influencing depth reduces. Although the present study limits to two-passes grinding, the forming mechanism of the hardened layer is applicable to grind-hardening of multi-passes or quenched steel.