1.25C-3.0Si超高碳钢的变形与组织分析

Deformation and Microstructure Analysis of an Ultrahigh Carbon Steel (1.25C-3.0Si) in Physical Simulation Tests

对喷射态超高碳钢UHCS-3.0Si进行了等温压缩物理模拟试验,测定了真应力-真应变曲线.试验表明,较低温度区(850～950°C)的变形激活能为395kJ/mol,变形主要受位错脱钉机制控制,较高温度区(1000～1100°C)的变形激活能为258kJ/mol,变形受位错攀移机制控制.对组织的观察表明,UHCS-3.0Si等温压缩过程中发生了动态再结晶,应变速率对组织影响不大,变形温度是决定组织的首要热力学条件.

Ultrahigh carbon steel (UHCS-3.0Si) was tested by isothermal compression physical simulation tests as spray-formed state, and true stress vs. true strain curves were obtained. The deformation activation energy is 395 kJ/mol and dislocation from being pinning is the deformation mechanism in lower temperature (850~950(°C)), where the deformation activation energy is 258kJ/mol and dislocation climb is the deformation mechanism in higher temperature (1 000~1 100(°C)). The dynamic recrystallizatin occurred during the isothermal compression. The strain rate has little effect on the microstructure and the deformation temperature is the key thermodynamics factor influencing the microstructures.