控冷冷速对高性能桥梁钢组织和力学性能的影响  

Effect of Controlled Cooling Rate on Microstructure and Mechanical Properties of a High Perfomance Steel for Bridge

作　　者：吴年春 崔强 范益 李恒坤 李翔 

机构地区：[1]南京钢铁股份有限公司研究院,江苏南京210035

出　　处：《钢铁》2014年第8期94-99,共6页Iron and Steel

摘　　要：为了使控轧控冷工艺生产的高性能Q500qE桥梁钢具有较低的屈强比和良好的韧性,采用Gleeble-3800试验机模拟了试验钢不同冷速控冷工艺,研究了冷速对组织和力学性能的影响。结果表明：5~25℃/s冷却速率下形成针状铁素体、粒状贝氏体铁素体和少量弥散M-A岛构成的多相组织。随冷速增加,铁素体晶粒细化,M-A岛尺寸减小;强度和屈强比提高,冲击功先升高后降低。试验钢满足力学性能要求的控冷冷却速率范围是15~20℃/s。In order to get a lower yield ratio and higher toughness of the high performance bridge steel Q500qE, relationship between microstructure and mechanical properties of the test steel varied with cooling rate was investigated with the Gleeble-3800 simulator. The results indicated that the microstructure of the test steel is primarily acicular ferrite （AF） and granular bainite ferrite （GBF） in all cooling rate, dispersed with M-A constituent under 5-25 ℃/s. Grain size of ferrite and maximum chord of M-A constituents decreased with the increasing of cooling rate, while the strength and yield ratio increased. The proper range of cooling rate for 500 MPa graded high performance bridge steel has been confirmed as 15- 20 ℃/s.

关 键 词：高性能桥梁钢 中温转变铁素体 M-A岛 力学性能 

分 类 号：TG335[金属学及工艺—金属压力加工] TG142.1[一般工业技术—材料科学与工程]