超快冷工艺下780MPa级工程机械用钢的组织与性能  

Microstructures and Properties of 780 MPa Engineering Machinery Steel Under Ultra Fast Cooling Process

作　　者：衣海龙[1] 徐洋[1] 肖爱达 刘振宇[1] 

机构地区：[1]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 [2]华菱涟钢技术中心,湖南娄底417000

出　　处：《东北大学学报（自然科学版）》2012年第11期1578-1581,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51104046);中央高校基本科研业务费专项资金资助项目(N090307001)

摘　　要：对780MPa级工程机械用钢进行了现场批量生产试制,对其组织与性能进行了研究.通过合理的成分设计,采用控制轧制和超快冷+层流冷却的两阶段冷却路径控制,获得了良好的组织与性能.结果表明:终轧后采用超快冷+层流冷却工艺,超快冷的出口温度在650℃,卷取温度在570℃,试验钢的屈服强度大于685 MPa,抗拉强度大于785 MPa,并具有良好的冲击性能、成形性能及焊接性能.试验钢的组织为铁素体+少量珠光体,同时,在铁素体的基体上,存在大量10nm左右的弥散析出或相间析出(Nb,Ti)(C,N),有效提高了试验钢的强度.A mass trial was carried out for a 780 MPa engineering machinery steel and the microstructures and properties of steel were investigated. The controlled rolling, ultra-fast cooling and laminar cooling process were used based on the optimized compositions of steel, and good microstructures and mechanical properties were obtained. The results showed that ultra fast cooling plus laminar cooling process is used after the finish rolling, and the outlet temperature of ultra fast cooling and coiling temperature are controlled at 650℃ and 570℃ , respectively. The yield and tensile strengths of steels are higher than 685 MPa and 785 MPa, respectively, and good impact resistance, formability and weldability are obtained. The microstructures of steels are composed with ferrite and a litlle of pearlite. A large number of （Nb,Ti） （C,N） precipitates are observed with size less than 10 nm dispersed in the ferrite matrix, and these fine precipitates increase the strength of steel effectively.

关 键 词：工程机械用钢 超快冷 铁素体 析出物 

分 类 号：TG142.1[一般工业技术—材料科学与工程]