控冷工艺对ML20MnTiB冷镦性能的影响  

Influence of controlled cooling on ML20MnTiB cold heading property

作　　者：张全刚[1] 翟林甫[1] 李印长[1] 龙广超[1] 

机构地区：[1]安阳钢铁股份有限公司,河南安阳455004

出　　处：《金属制品》2011年第1期76-78,83,共4页Metal Products

摘　　要：用ML20MnTiB替代ML40Cr作为冷镦钢盘条,以减少冷镦前退火处理工序。介绍ML20MnTiB盘条化学成分及轧制工艺流程,斯太尔摩线长度104m,盘条在斯太尔摩线上的运行时间由290s提高到373s,在保温罩内的运行时间由179 s增加到271s,在保温罩内的平均冷却速度由0.44℃/s降到0.38℃/s。工艺调整后,盘条屈服强度和抗拉强度均降低约30～40 MPa,组织全部为铁素体加珠光体,心部不存在粒状贝氏体,心部晶粒度由8.5级增大到7.5级,1/3冷镦合格率由原来的75%提高到100%。Annealing treatment process before cold heading is reduced while ML40Cr is replaced by ML20MnTiB to act as cold heading steel wire rod. ML20MnTiB wire rod rolling process flow and chemical composition are introduced. Stelmor line length is 104 m, running time of wire rod on Stelmor line is increased from 290 s to 373 s, running time in heat holding cover is increased from 179 s to 271 s. The average cooling speed in heat holding cover is decreased from 0.44℃/s to 0.38℃/s. The yield strength and tensile strength of wire rod are decreased about 30 -40 MPa after process adjusting. Structure are ferrite and pearlite, there is no granular bainite in center. Central grain size is larged from grade 8.5 to grade 7.5. 1/3 cold heading pass percent is increased from 75% to 100%.

关 键 词：ML20MnTiB 控冷工艺 冷镦钢 斯太尔摩线 

分 类 号：TG335.63[金属学及工艺—金属压力加工]