摘要
分析了B在中碳铝镇静钢中的存在形式及对其动态连续冷却转变行为的影响。利用Gleeble1500模拟试验机,结合金相观察及硬度检测结果,测定并绘制了不同B含量中碳铝镇静钢的CCT曲线。使用Thermal-Calc热力学软件计算了B对钢中析出相析出的影响,同时使用透射电镜(TEM)观察了钢中析出相的形貌。结果表明,随着冷速的提高,3种试验钢的组织均由铁素体-珠光体组织向贝氏体-马氏体组织转变。试验钢中B的加入能够抑制AlN的析出,降低细小AlN对晶界的钉扎作用,使晶粒粗化,硬度降低。钢中起到提高淬透性作用的B为固溶B,BN没有提高淬透性作用。进一步提高B含量,钢中固溶B含量增加,钢材的淬透性提高,试验钢在较低冷速下即能获得贝氏体-马氏体型组织。
The existing form of boron in medium-carbon Al-killed steel and the effect of boron on dynamic continuous cooling transformation behavior of medium-carbon Al-killed steel with different boron contents were analyzed.The continuous cooling transformation curves of medium carbon Al-killed steel with different contents of boron were determined by using Gleeble1500 simulation test machine combined with the result of microstructure observation and Vickers hardness.The Thermal-Calc thermal software(data base TCFE10.0)was employed for calculating the precipitation of experimental steels,and the precipitates were observed using transmission electron microscope.The results show that the microstructure of experimental steels change from ferrite-pearlite to bainite-martensite with the increase of cooling rate.The precipitation of AlN is inhibited by the addition of boron.It leads to coarse grains and decrease of Vickers hardness due to the decrease of tiny AlN particles which could pin the grain boundary.Boron in solid solution can play a role of improving hardenability.BN is useless for improving hardenability.With further increasing the content of boron,the hardenability of experimental steels improves due to the increase of boron in solid solution.Therefore,the microstructure of bainite-martensite type can be obtained easier at a lower cooling rate.
作者
臧若愚
李晶
刘伟建
黄飞
ZANG Ruoyu;LI Jing;LIU Weijian;HUANG Fei(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China)
出处
《钢铁研究学报》
CAS
CSCD
北大核心
2023年第12期1560-1568,共9页
Journal of Iron and Steel Research
关键词
CCT曲线
淬透性
铝镇静钢
连续冷却转变
B含量
CCT curve
hardenability
Al-killed steel
continuous cooling transformation
boron content
