Cr12Mo1V1冷作模具钢CCT曲线及球化组织退火工艺
CCT CURVE OF Cr12Mo1V1 COLD WORK DIE STEEL AND SPHEROIDIZED MICROSTRUCTURE ANNEALING PROCESS
邱桂娟 1王然 1何宁 1尤晓东 2米永旺 3张占普 1芦彦 1康杰4
作者信息
- 1. 河冶科技股份有限公司,河北石家庄 052165;河北省高速工具钢技术创新中心,河北石家庄 052165
- 2. 河冶科技股份有限公司,河北石家庄 052165;河北省高品质工模具材料重点实验室,河北石家庄 052165
- 3. 河冶科技股份有限公司,河北石家庄 052165
- 4. 河北省高品质工模具材料重点实验室,河北石家庄 052165
- 折叠
摘要
Cr12Mo1V1冷作模具钢合金含量高、导热性较差,对其轧制坯设定合理的退火工艺尤为重要.利用Gleeble热模拟试验机测定了 Cr12Mo1V1冷作模具钢的相变膨胀曲线,结合金相组织和硬度检测获得了该钢的CCT曲线,同时研究了不同退火工艺对组织的影响规律.结果表明,Cr12Mo1V1冷作模具钢中珠光体组织的转变相区在600～827℃,贝氏体组织的转变相区在300～500℃,马氏体组织转变的临界冷速为0.5℃/s;随着冷速的增加,硬度逐渐增大,在冷速0.5 ℃/s时达到最大值并趋于稳定;当退火工艺中奥氏体化温度为890～920℃时,碳化物球化效果不佳,且部分碳化物沿晶界析出;当退火工艺中奥氏体化温度为850～860℃时,组织由细小粒状珠光体和少量未转变的残余奥氏体构成;随球化保温时间延长,碳化物的球化效果越好.结合CCT曲线可确定,退火工艺中的奥氏体化温度宜接近Ac1相变点,但不能超过该温度.
Abstract
Cr12Mo1V1 cold work die steel has high alloy content and poor thermal conductivity,so it is particularly important to set a reasonable annealing process for its rolling billet.The phase transformation expansion curve of Cr12Mo1V1 cold work die steel was determined by Gleeble thermal simulation testing machine,and the CCT curve of the steel was obtained by combining metallographic microstructure and hardness testing,and the influence of different annealing processes on the microstructure was studied.The results show that the transition phase zone of the pearlite structure is 600～827 ℃,the transition phase region of the bainite structure is 300～500℃,and the critical cooling rate of the martensite structure is 0.5℃/s with the increase of the cooling rate,and the hardness gradually increases with the increase of the cooling rate,reaching the maximum value and become stable at the cooling rate of 0.5 ℃/s,and the austenitization temperature is 890～920 ℃,the spheroidization effect of carbide is not good,and some carbides are precipitated along the grain boundary;when the austenitization temperature in the annealing process is 850～860 ℃,the structure is composed of fine granular pearlite and a small amount of untransformed residual austenite.Combined with the CCT curve,it can be determined that the austenitization temperature in the annealing process should be close to,but not exceeded,the Ac phase transition point.
关键词
Cr12Mo1V1/冷作模具钢/CCT/碳化物/硬度/球化退火Key words
Cr12Mo1V1/cold work die steel/CCT/carbide/hardness/spheroidization annealing引用本文复制引用
出版年
2023
NETL
NSTL
维普
万方数据