摘要
在Gleeble-1500热模拟机上采用热膨胀法,测定了一种Mn-Si-V系贝氏体辙叉钢的连续冷却转变曲线。利用DMI 5000M型光学显微镜、Hitachi H-800透射电镜和显微维氏硬度计对不同冷速下试验钢的显微组织和硬度进行分析,并就合金元素对贝氏体相变和显微组织的作用进行讨论。结果表明,试验贝氏体钢的相变点为：Ac1=730℃、Ac3=873℃、Ms=320℃。以0.05℃/s的冷速冷却时,试验贝氏体钢获得以上贝氏体为主的组织;在0.05~1.0℃/s的冷速范围内,试验贝氏体钢可以获得以无碳化物贝氏体为主的组织;当冷速大于1.0℃/s,试验贝氏体钢得到无碳化物贝氏体/马氏体复相组织,并且随冷速增加马氏体含量增大;当冷速达到8.0℃/s,试验贝氏体钢获得以低碳马氏体为主的组织。
The continuous cooling transformation curve of a Mn-Si-V bainitic steel for frog was measured by dilatometry on a Gleeble-1500 simulator. The microstructure and hardness of the tested steel with different cooling rates were analyzed by DMI 5000 M optical microscope,Hitachi H-800 transmission electronic microscope（ TEM） and micro-vickers hardness tester,and the impact of alloying elements on bainitic transformation and microstructure was discussed. The results indicate that the transformation temperature of the tested bainitic steel are Ac1=730 ℃,Ac3= 873 ℃,Ms = 320 ℃. The tested bainitic steel is composed mainly of upper bainite under the cooling rate of 0. 05 ℃/s,and carbide-free bainite under the cooling rate 0. 05-1. 0 ℃/s. If the cooling rate is greater than 1. 0 ℃/s,the microstructure of the tested bainitic steel is carbide-free bainite/martensite. When the cooling rate is greater than 8. 0 ℃/s,the microstructure of the tested bainitic steel is mainly martensite.
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第1期17-21,共5页
Heat Treatment of Metals
基金
国家重点研发计划(2017YFB0304500)
关键词
贝氏体钢
辙叉
连续冷却转变曲线
热膨胀法
bainitic steel
frog
continuous cooling transformation curve
dilatometry
