双相钢冷拔钢丝非铅浴淬火工艺的研究

Investigations of Non-patenting Process for Cold Drawing Dual Phase Steel Wires

本文研究了热轧态铁素体+马氏体型双相钢线材冷拔—回复—冷拔过程(简称LHL工艺)的力学性能及显微组织的变化。试验结果表明:(1)双相钢线材的冷拔形变强化可分两个阶段,第一阶段为减速强化阶段,在σ—ε曲线上的斜率(dσ/dε)随ε的增加而减小。第二阶段为恒速强化阶段,σ—ε关系符合珠光体型冷拔强化的Embury-Fisher关系。第一阶段与第二阶段分界的ε值约为1.20—1.50;(2)双相钢的冷拔强化虽然可以获得2300MPa以上的强度水平,但塑性、韧性严重恶化,难以实际应用。冷拔钢丝的回复及回复后的冷拔,是双相钢冷拔形变强化及韧化的有效途径。本文用SEM、TEM电镜观察了显微组织,对LHL工艺的强化与韧化机理进行了分析。

The mechanical properties and microstructures of dual phase steel wires drawn by a process named 'LHL' (cold drawn-recorvy-cold drawn)have been investigated. The results show that, (1)The drawn strengthening can be divided into two segments. The first segment is characterised by constant rate strengthening, and accord with an experience formula suggested by Embury and Fisher. (2)Recovery and followed by a small amount of drawing are important for toughening and strengthening. Microstructures of wire have been observed by means of SEM. Mechanism of toughening and strengthening has been discussed.