摘要
利用Formastor-Digital膨胀仪测定了Nb-V复合微合金化中碳非调质钢的连续冷却转变曲线（CCT曲线）,并测定了不同冷速下实验钢硬度的变化。分析了不同Nb、V含量对中碳非调质钢连续冷却转变的影响。结果表明,随着Nb、V含量的增加,相变点温度随之降低,并使得转变过程中珠光体、贝氏体转变区域变宽,组织中相应的体积分数增加。冷速在0.08-1℃/s时,组织主要为铁素体和珠光体;当冷速大于2.5℃/s时,开始发生贝氏体转变,随着冷速的进一步增加,贝氏体含量越来越多,并在5℃/s时出现马氏体组织。Nb-V复合微合金化实验钢受冷速的影响较大,随冷速的增大实验钢的显微硬度也随之提高。冷速分别在10℃/s和30℃/s时,硬度突然增大。
The continuous cooling transformation （CCT） curves of Nb-V alloyed medium carbon non-quenched and tempered steels were measured by using Formastor-digital thermal dilatometer. Hardness of the tested steels under different cooling rates was measured, and the effect of Nb and V contents on continuous cooling transformation of the tested steels was investigated. The experimental results show that the phase transformation temperatures are decreased,the transformation regions of pearlite and bainite broaden and the volume fraction of the corresponding transformed product increase with increasing of Nb and V contents in the steel. Microstructure of ferrite and pearlite can be obtained with a cooling rate from 0.08 ℃/s to 1 ℃/s. When the cooling rate is higher than 2.5 ℃/s, bainite transformation occurs, more bainite microstructure can be obtained with increasing of cooling rate. In addition, martensite is observed in the steel when cooling rate is 5℃/s. Micro-hardness of the tested steels increases with increasing of cooling rate. Micro-hardness of the steel increases apparently for cooling rate at 10℃/s and 30℃/s.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第5期44-49,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(50574010)
教育部博士点基金(20060008015)
