均匀化工业电解镍高温热变形行为的研究

Study of high-temperature hot deformation behavior of electrolytic nickel in homogenized industy

摘要:

采用Gleeble-3500热模拟试验机对均匀化后的工业电解镍进行了热压缩实验,在变形量60%的条件下,研究了变形温度为900,1000,1100,1200 ℃,应变速率为0.01,0.1,1,10 s_-1^{时的热变形行为。根据压缩数据获得真应力}-真应变曲线,分析了变形温度和应变速率对电解镍力学性能的影响,并得到流变应力本构方程,基于动态材料模型及Prassd失稳准则建立了热加工图。结果表明：电解镍对变形温度和应变速率表现出较强的敏感性,随变形温度的升高和应变速率的降低,流变应力逐渐减小；随应变的增加,流变应力达峰值下降至某一值后趋于平稳,呈现出流变软化特征；根据热加工图,获得电解镍较佳的热加工工艺范围为：变形温度980~1040 ℃,应变速率3.16~10 s_-1^；变形温度为1100 ℃,应变速率为1~4 s_-1^。

关键词:电解镍;热变形行为;本构方程;热加工图

Abstract:

Hot deformation experiments were carried out on homogenized industrial electrolytic nickel using a Gleeble-3500 hot simulation tester, and the hot deformation behaviors were investigated at deformation temperatures of 900, 1000, 1100, and 1200 °C, and at strain rates of 0.01, 0.1, 1, and 10s_-1 ^{at a deformation amount of 60%}.The true stress-true strain curves were obtained based on the compression data, the effects of deformation temperature and strain rate on the mechanical properties of electrolytic nickel were analyzed, and the rheological stress eigenstructure equations were obtained, and the thermal processing diagrams were established based on the dynamic material model and the Prassd instability criterio.The results show that electrolytic nickel exhibits strong sensitivity to deformation temperature and strain rate, and the rheological stress decreases gradually with the increase of deformation temperature and the decrease of strain rate;The rheological stress reaches a peak and decreases to a certain value and then tends to stabilize, showing the characteristics of rheological softening;According to the thermal processing diagram, the better thermal processing range of electrolytic nickel is obtained as follows: deformation temperature 980~1040 °C, strain rate 3.16~10s_-1^; deformation temperature 1100 °C, strain rate 1~4 s_-1^.

Key words:Electrolytic nickel; Thermal deformation behavior; Constitutive equations; Thermal processing diagram