AlN析出行为对低碳钢深拉拔加工硬化的影响  

AlN precipitation behavior and its effect on work hardening of low carbon steel in deep drawing process

作　　者：罗志俊[1] 王丽萍[1] 孙齐松[1] 李舒笳[1] 马跃[1] 王晓晨[1] 

机构地区：[1]首钢技术研究院,北京100043

出　　处：《材料热处理学报》2016年第3期48-53,共6页Transactions of Materials and Heat Treatment

摘　　要：采用热力学软件Thermo-Calc计算、热模拟及TEM观察的试验方法,分析了低碳钢AlN析出行为以及其对热轧材、拉拔材加工硬化的影响。实验结果表明,未进行工艺调整的试验钢其深拉拔过程中强度增量ΔRm与减面率γ的关系式为ΔRm=33.0＋6.02γ,缓冷工艺时对应的关系式为ΔRm1=24.1＋5.03γ,缓冷钢的加工硬化明显低于原工艺;低温铁素体区AlN的析出是热轧材屈服强度和深拉拔加工硬化率降低的原因。通过控制低温区固溶N的析出,屈服强度由原来的340 MPa降为300 MPa,屈强比由原来的0.655降为0.610。在此成分体系下,AlN在奥氏体区析出温度范围为900-1000℃,950℃为鼻子温度;在铁素体区主要析出温度范围为650-750℃,700℃析出最多,上述实验结果为现场斯太尔摩线冷却工艺控制提供技术依据。AlN precipitation behavior and its effect on work hardening of a hot-rolled low carbon steel under different drawing processes was investigated by means of thermo-calc software,thermal simulation and TEM. Different relationship of the strength increment ΔRmand reduction rate γ was obtained for the steel with different deep drawing processes. The results indicate that the work hardening of the slow cooled steel is significantly lower than that of the steel by the original process due to the decrease in yield strength and work hardening rate caused by AlN precipitation in ferrite region. By controlling precipitation of solute N,the yield strength decreased from 340 MPa to300 MPa and the yield ratio is reduced from 0. 655 to 0. 610. The AlN precipitation in the steel occurs at 900-1000 ℃ with the nose temperature of 950 ℃ in the austenite region. In the ferrite region,the precipitation temperature ranged from 650 ℃ to 750 ℃ with the maximum precipitation at 700 ℃.

关 键 词：低碳钢 深拉拔 AlN析出 加工硬化 

分 类 号：TG142.24[一般工业技术—材料科学与工程]