含硼低碳贝氏体钢的TMCP工艺模拟  

Simulation of TMCP process on a low-carbon bainitic steel contained boron

作　　者：张慧云[1] 李艳梅[2] 

机构地区：[1]山西工程职业技术学院,山西太原030009 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《金属热处理》2013年第7期99-103,共5页Heat Treatment of Metals

摘　　要：研究了一种Mn-Nb-B系低碳贝氏体钢,在MMS-300多功能热力模拟试验机上模拟不同的TMCP工艺制度,分析试验钢的显微组织及硬度,从而确定该试验钢最佳TMCP参数组合。变形量为15%、30%和50%时,试验钢相变组织均为单相粒状贝氏体。变形量为50%时,其显微组织均匀细小,硬度较高;变形温度为880、850、820、780℃时,试验钢相变组织都是以粒状贝氏体为主,变形温度较高时,组织较粗大。变形温度较低时,组织中铁素体较多,中间变形温度为850℃时,组织为均匀细小的粒状贝氏体,硬度较高;终冷温度为600、550、500、400℃时,相变组织都是铁素体和粒状贝氏体。终冷温度越低,组织越细小,但在400℃出现板条贝氏体,在终冷温度为500℃时,组织为均匀细小的粒状贝氏体,硬度也较高。最终确定该试验钢最佳的TMCP工艺参数为:变形量50%、变形温度850℃、终冷温度500℃。A low-carbon bainitic steel of Mn-Nb-B system was studied. Different TMCP processes was simulated by MMS-300 multifunction thermal simulation testing machine, and microstructure and microhardness of the tested steel were analyzed, so the optimal combination of TMCP parameters was obtained. The resuhs show that, the microstructure of the specimens with deformation of 15%, 30% and 50% is granular bainite, and the specimen with deformation of 50% has a relative finer mierostructure and higher hardness. The microstruetures of the specimens with deformation temperature of 880, 850, 820 and 780 ℃ are mainly granular balnite. The higher deformation temperature leads to a coarser microstructure, but the amount of ferrite is more in specimen with lower deformation temperature, so the specimen with moderate deformation temperature of 850 ℃consists of uniform fine granular bainite with a higher hardness. The microstructure of the specimens with final cooling temperature of 600,550,500 and 400 ℃ consists of ferrite and bainite. The mierostructure of the specimen with a lower final cooling temperature is finer, but there is lath-bainite in the specimen with final cooling temperature of 400 ℃, while the microstructure is uniform fine granular bainite with relatively higher hardness, when the final cooling temperature is 500 ℃. So the optimal deformation, deformation temperature and final cooling temperature for the TMCP process are 50%, 850 ℃ and 500 ℃, respectively.

关 键 词：低碳贝氏体钢 TMCP 显微硬度 显微组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程]