基于热加工图的喷射成形含铌高速钢的热变形  

Hot Deformation of Spray-Formed Nb-Containing High Speed Steel——A Study Using Processing Map

作　　者：卢林[1] 侯陇刚[1] 王和斌[1] 张金祥[1] 崔华[1] 黄进峰[1] 张永安[2] 张济山[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083 [2]北京有色金属研究总院有色金属材料制备加工国家重点实验室,北京100088

出　　处：《材料研究学报》2015年第7期496-504,共9页Chinese Journal of Materials Research

基　　金：国家重点基础研究发展计划2011CB606303资助项目~~

摘　　要：结合以铌代替部分钒的合金化思路和用喷射成形快速凝固技术制备出新型M3:2高速钢,研究了合金在950-1150℃和0.001-10 s-1条件下的热变形。根据实验得到的真应力-真应变曲线,基于动态材料模型(DDM)建立合金热加工图并结合动力学分析和组织观察,将加工图分为塑性失稳区(>1 s-1)、低应变速率区(0.001 s-1)、低变形温度区(<1000℃)和加工安全区,重点讨论了低应变速率区和低变形温度区内裂纹产生的机制,并由此确定了合金可进行热加工的区间为1050-1150℃,0.01-0.1 s-1。为了得到晶粒细小、碳化物呈颗粒状且分布均匀的组织,优化后的热变形加工参数为1150℃,0.1 s-1。喷射成形含铌M3:2高速钢经锻造和热处理后,其硬度和弯曲强度等性能优于同等成分的粉末冶金高速钢。The hot deformation behavior of as spray-formed Nb-containing AISI M3： 2 high speed steel has been investigated by compression tests at a temperature range of 950-1150℃ and a strain range of 0.001-10 s^-1with 50% reduction. Processing maps were developed according to the principles of Dynamic Material Model. It was found that the flow curves assumed the classic shape of dynamic recrystallization（DRX）-rising to a peak, following a softening to a steady state. The hot working process of the steel can be carried out safely in the domain of（Td： 1050-1150℃, ε： 0.01-0.1 s^-1）. To obtain microstructures of the steel with fine grains and uniform distribution of fine granular carbides, the hot working process should be carried out at 1150℃ and strain rate of 0.1 s^-1. The flow instability took place when strain rates exceed 1 s^-1. After a proper hot working and heat treatment, the hardness and bending strength of the spray-formed Nb-containing M3：2 high speed steel is 67 HRC and 3467 MPa, respectively.

关 键 词：金属材料喷射成形 高速钢 热变形 热加工图 铌 

分 类 号：TG142[一般工业技术—材料科学与工程]