摘要
采用低碳和添加铌、钒、钛、铬等微合金元素的成分设计,利用洁净钢冶炼、奥氏体再结晶区粗轧、奥氏体未再结晶区精轧等工艺生产90 mm厚Q460钢板,热轧后采用大流量低辊速控制策略的1次水冷工艺和小流量间断开水控制策略的3次往复式水冷工艺进行水冷,研究不同水冷工艺对钢板组织和力学性能的影响,以获得合适的水冷工艺。结果表明:1次水冷工艺生产的试验钢板的显微组织主要为针状铁素体+少量珠光体,3次往复式水冷工艺生产的试验钢板的显微组织主要为多边形铁素体+珠光体+少量粒状贝氏体;与3次往复式水冷工艺相比,1次水冷工艺生产的试验钢板厚度方向的组织更加均匀、细小,且形成了针状铁素体。2种水冷工艺生产的试验钢板的拉伸性能和冲击韧性均满足标准要求,但是1次水冷工艺生产的试验钢板的−40℃冲击韧性明显优于3次往复式水冷工艺生产的试验钢板,且厚度方向的冲击韧性更均匀。90 mm厚Q460钢板热轧后的合适水冷工艺为1次水冷工艺,所得钢板的屈服强度为495~512 MPa,抗拉强度为604~616 MPa,断后伸长率23%~24%,−40℃冲击吸收功为200 J以上。
The 90 mm thick Q460 steel plates were produced by clean steel smelting,rough rolling in austenite recrystallization zone and fine rolling in austenite non-recrystallization zone with the composition design of low carbon and adding micro-alloying elements such as niobium,vanadium,titanium and chromium.The steel plates were watercooled by one-time water-cooling process with large flow and low roll speed control strategy and three-time reciprocating water-cooling process with small flow and intermittent water control strategy after hot-rolling.The effects of different water-cooling processes on the microstructure and mechanical properties of steel plates were studied in order to obtain suitable water-cooling process.The results show that the microstructure of the test steel plate produced by one-time water-cooling process was mainly acicular ferrite+a small amount of pearlite,while that of the test steel plate produced by three-time reciprocating water-cooling process was mainly polygonal ferrite+pearlite+a small amount of granular bainite.Compared with that by three-time reciprocating water-cooling process,the microstructure in thickness direction of the test steel plate produced by one-time water-cooling process was more uniform and finer,and acicular ferrite was formed.The tensile properties and impact toughness of the test steel plates produced by the two kinds of water-cooling processes met the standard requirements,but the impact toughness of the test steel plate produced by one-time watercooling process was significantly better than that produced by three-time reciprocating water-cooling process at−40℃,and the impact toughness in the thickness direction was more uniform.The suitable water-cooling process for Q460 steel plate with a thickness of 90 mm after hot-rolling was one-time water-cooling process,and the steel plate had the yield strength of 495–512 MPa,tensile strength of 604–616 MPa,percentage elongation after fracture of 23%–24%,and impact absorption energy of more than 200 J at−40℃.
作者
付龙虎
周文平
朱小超
FU Longhu;ZHOU Wenping;ZHU Xiaochao(School of Mechanical Engineering,Sichuan Vocational and Technical College of Chemical Engineering,Luzhou 646000,China;School of Physics and Electrical Engineering,Liupanshui Normal University,Liupanshui 553004,China;School of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310018,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第7期30-33,共4页
Materials For Mechanical Engineering
基金
浙江省重点研发计划项目(2020A01027)。
关键词
厚规格Q460钢板
热轧后的水冷工艺
拉伸性能
低温冲击韧性
thick specification Q460 steel
water cooling process after hot-rolling
tensile property
low temperature impact toughness
