摘要
针对高品质特殊钢(如CTHQ25、1Cr11Ni2W2MoV、30CrNi4Mo等)现有轧/锻棒料工艺退火后硬度(HB)超标(>270)、同炉硬度不均匀(270~290),退火周期长(不同直径棒料退火40~60 h不等)等难题,开展短周期退火软化工艺及设备工装设计应用研究。以轧/锻态CTHQ25钎具钢为例,基于热力学计算和试验研究,揭示了退火软化机理,设计出一步退火工艺、两步退火工艺,阐明了原始组织、退火温度、退火时间对退火组织和硬度的影响规律。结果表明,采用"低温-高温"两步退火工艺后硬度(HB)由原工艺的276降至240。同时,基于温度场-流场耦合模拟计算,设计工装垫块,将原堆垛式布料优化为平铺式布料,提高了炉温均匀性,保证了同炉产品硬度的均一性(241±4),退火工艺周期缩短20%以上。
The technical issues such as machinability,hardness uniformity and longer annealing time present for a wrought and hot-rolled special steels(e.g.CTHQ25,1Cr11Ni2W2MoV,30CrNi4Mo)manufactured by Pangang Jiangyou Changcheng Special Steel Co.,Ltd.In order to address those issues,a a hot-rolled CTHQ25 drill steel had been used,a single-step heat-treating route was designed to soften the steel to less than HB 260 based on thermodynamic calculations of phase stability and experimental study on kinetics of phase evolution.To accelerate the annealing process,a double-step annealing,where the first step annealed at a lower temperature to promote the decomposition of retained austenite and the second step annealed at a higher temperature to accelerate microstructure coarsening,was designed and carried out to achieve a hardness of HB 240.In the meantime,special consideration was given to workpiece layout in the furnace to ensure hardness uniformity.With the coupled numerical simulation of temperature-fluid field of the furnace,the workpiece layout in the furnace was optimized with fixture topologically re-designed to achieve the maximum fuel efficiency and temperature uniformity in contrast to originally random stacks of workpieces.
作者
闫扶摇
朱磊
陈宏涛
杨莹
李昱炀
轩欢欢
张军
蔡佑刚
段丕荣
李国
周茂华
罗定祥
张雁祥
闫牧夫
Yan Fuyao;Zhu Lei;Chen Hongtao;Yang Ying;Li Yuyang;Xuan Huanhuan;Zhang Jun;Cai Yougang;Duan Pirong;Li Guo;Zhou Maohua;Luo Dingxiang;Zhang Yanxiang;Yan Mufu(School of Material Science and Engineering,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China;School of Material Science and Engineering,Harbin University of Science and Technology,Harbin 150040,Heilongjiang,China;Changcheng Special Steel Company,Pangang Group,Jiangyou 621701,Sichuan,China)
出处
《钢铁钒钛》
CAS
北大核心
2021年第2期152-160,共9页
Iron Steel Vanadium Titanium
关键词
高品质特殊钢
退火
软化机理
退火周期
平铺布料
high quality special steel
annealing
mechanism of softening
annealing time
flat configuration of steel
