摘要
通过Formaster-F热膨胀仪和Gleeble-1500热/力模拟试验机分别模拟了奥氏体化温度为910℃和960℃时不同直径的无碳化物贝氏体/马氏体(CFB/M)复相钢圆棒在空气中的冷却速率,采用光学显微镜和扫描电镜分析了奥氏体化温度和冷却速率对CFB/M复相钢显微组织的影响,测定了CFB/M复相钢的硬度和冲击韧度值。结果表明,在空冷条件下,随圆棒直径增大,CFB/M复相钢的组织由无碳化物贝氏体+马氏体转变成铁素体+无碳化物贝氏体,硬度随之降低,但冲击功却显著增加。提高奥氏体化温度,可抑制铁素体析出,使CFB/M复相钢在更大的冷速范围内获得强韧性好的CFB/M复相组织。
The process of air cooling about CFB/M steel bar with different diameter after austenizing at 910℃ and 960 ℃ was simulated by Formaster-F thermal dilatometer and Gleeble-1500 thermal/mechanical simulation machine respectively. The microstructure of the experimental steel was observed by optical microscope and scanning electron microscope. The hardness and impact toughness of the experimental steel was tested. The results show that in the air cooling condition, with the diameter of the steel bar increasing, the microstructure changed from CFB ＋ M mixed microstructure to Ferrite ＋ CFB microstructure. The hardness decreases but the impact toughness increases with the diameter of the experimental steel bar increasing. The proeutectiod ferrite is restrained and the CFB/M mixed microstructure is obtained in a wider range of cooling rate with increasing austenizing temperature.
出处
《金属热处理》
EI
CAS
CSCD
北大核心
2007年第12期61-63,共3页
Heat Treatment of Metals
基金
国家973计划基金(2004CB619105)
华北电力大学电力科学基金
