工具材料的高温硬度

An Investigation on High Temperature Hardness of Tool Materials

6种工业用合金工具钢及7种WC-Co烧结合金维氏硬度(H)与温度(T)关系的研究表明,经淬火—回火二次硬化处理的工具钢,在回火温度以下,可逆软化与温度呈线性关系,且各高速钢可逆软化系数很接近;提出了计算高速钢500℃以下硬度的简易公式。高于回火温度时,工具钢H—T关系复杂化,但直到700℃,影响高温硬度的主要因素仍然是热处理(二次硬化)达到的室温硬度。WC-Co烧结合金的硬度在800℃以下和温度呈线性关系,当Co≤20％时,与钴含量也呈显著的线性关系;提出了由室温硬度或钴含量(3％—20％)计算800℃以下硬度的简易公式。

The relationships between Yickers hardness (H) and Temperature (T) for six industry alloying tool steels and seven WC-Co sintered alloys have been investigated. When T is lower than tempered, the reversible softening value for tool steels undergone quenchingtempering secondary hardening treatment is a linear function of T. The diferences among reversible softening factors for various high speed steels (HSS) are very small. Hence, a simple relation to estimate the hardness of HSS at T below 500℃ is presented. When T is higher than tempered, the H-T relation of tool steels is complicated, but H is still mai- nly determined by the room temperature hardness after heat treatment. For WC-Co sintered alloys, the H-T relation is linear up to 800℃, and the relation between H and cobalt content (Co%) is also linear when Co<20%. The relation tor estimating hardness of WC-Co alloys from T (800℃) and Co (3%-20%) is presented.