摘要
对一种低合金高碳钢(O．81C,0．65Cr,0．89W,0．54Mo,0．23V)热处理组织及硬度研究表明,该钢退火具有多类型碳化物(M3c,M4C3,M23C6,M6C和MC),在800-840℃区间退火,处于γ相低温区原碳化物部分溶解和新碳化物重新形核生长过程,使碳化物颗粒超细化,平均尺寸0．33-0．34μm．淬火时,因M3C、M23C6溶解于奥氏体的速度较快,在840-860℃淬火时,硬度可达HRC63-65；未溶碳化物M6C和MC(VC)有利于马氏体细化,但因其数量较少,淬火最高温度不易超过880℃．该钢在低温和中温回火有较好的抗回火性能,并能有效地促进残余奥氏体转变。该钢热处理过程组织结构特征能较好地以相平衡热力学计算结果进行解释．
The structure and hardness of a low - alloy high carbon steel （0. 81C,0.65Cr,0.89W,0.54Mo, 0.23V） during heat treatment are studied in this paper. The results show that there are multiple types of carbides M3C, MTC3, M23C6, M6C and MC in the steel after annealing. Nucleation and growing of new carbides, dissolution of previous partial carbides during annealing process in g phase region, all these result in ultra - fine distfibution. Average size of annealed carbide in the steel is 0.33 ～ 0.34 mm at 800 ～ 840 ℃. Because M3 C and M23C6 dissolve easily in austenite, the higher hardness HRC63 ～ 65 can be obtained at 840 ～ 860 ℃. Undissolved carbide in the steel is propitious to martensite thinning during quenching process and it＇s quantity is little, so quenching optimal temperature is lower than 880℃. The good temper -resistance for the steel is obtained and the retained austenite is dispelled effectively at low and middle temperature. The structure of the steel during heat treatment can be described accurately by calculating based on phase equilibrium thermodynamic.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2006年第1期60-62,108,共4页
Materials Science and Technology
关键词
低合金钢
超细碳化物
热处理
组织结构
low - alloy steel
ultra - fine carbide
heat treatment
structure
