Cr-W-Mo-V中合金钢的淬火硬度计算及其回火硬度特性

Quenching Hardness Calculation and Tempering Hardness Characteristic of Cr-W-Mo-V Medium-alloy Steel

研究了4种不同成分的Cr-W-Mo-V中合金钢的淬火硬度、回火硬度变化和组织结构转变。在淬火基体成分计算的基础上提出了该钢淬火硬度与某一淬火温度下奥氏体基体化学成分关系的近似计算公式。此类钢均具有较高的抗回火性,随着Cr、W、Mo、V含量的增加,不同类型碳化物的沉淀强化可使回火硬度出现低温二次硬化区或平台区,甚至高温二次硬化区。讨论表明,上述淬火硬度计算公式隐含着洛氏硬度测定和马氏体强化机理的对应关系,对其它钢种也适用。

The changes of quenching and tempering hardness and the microstructure transformation of four kinds of Cr-W-Mo-V medium-alloy steels were investigated. On the basis of matrix composition calculation,the formula of the quenching hardness of the steels have been put forward according to austenite compositions at some austenitizing temperature. The good temper-resistance of the steels was obtained at tempering, With the increase of Cr, W, Mo and V content, secondary hardening or platform at low tempering temperature, even secondary hardening at high temperature appear with different types of carbides precipitated. Above quenching hardness formula implies the corresponding relation between rockwell hardness measurement and the mechanism of martensite strengthening. The formula is suitable for other steels.