中碳钢温变形的力学特性

Mechanical Characteristics of Warm Deformation of Medium Carbon Steel

利用Gleeble-3500热模拟实验机对中碳钢铁素体+珠光体组织进行温变形压缩试验,研究其在不同变形温度(500～700℃)和应变率(0.001～10s-1)条件下的流变行为及其主导机制.研究结果表明:温变形过程先从铁素体变形开始,而后珠光体开始变形,渗碳体片层结构被破坏;铁素体晶粒细化至1～2μm;珠光体片层被破坏使流变应力形成峰值;温变形流变应力曲线特征具有显著差异性,对工件塑性成形、工模具载荷分布及变形产生重要影响.

To study the warm deformation process of medium carbon steel, the compression experiment was conducted using Gleeble-3500 thermal/mechanical simulator system under the conditions of temperature from 500 to 700 ℃ and the strain rate from 0. 001 to 10 s^-1. The experimental results indicate that the deformation process begins from ferrite first, and then the pearlite part, which makes the brokenness of lamellar cementite. Ferrite grain could be refined till 1-2μm. Slice layer destruction give rise to the peak value of flow stress. Results also show that the flow stress curve of warm deformation is significantly different from that of hot deformation. This research could give some meaningful references to analyze warm plastic forming process and improve the manufacturing technology.