超临界马氏体不锈钢热变形行为

Hot behavior of supercritical martensitic stainless steel at elevated temperature

在Gleeble-3500热模拟试验机上对超临界马氏体不锈钢进行等温压缩试验,研究其高温流变行为,获得超临界马氏体不锈钢在温度为900~1 150℃、变形速率为0.005~5 s^(-1)时合金的热变形行为和组织演变。通过对实验数据的分析、拟合建立材料的高温流变模型,并分析Johnson-Cook(JC)模型和Arrhenius模型对超临界马氏体不锈钢的适用性。研究结果表明:修正后的JC模型和Arrhenius模型具有更高的精度。在应变速率较高时,修正的JC模型的预测值更接近实验值;在应变速率较低时,应变补偿的Arrhenius模型的预测值更接近实验值。载荷预测结果与实验值拟合程度较好,表明建立的模型能够描述材料的高温流变行为。

Isothermal hot compression tests of supercritical martensitic steel were performed on a Gleeble-3500 thermo-mechanical simulator at the temperature range of 900-1 150 ℃ and the strain rate range of 0.005-5 s^-1 to obtain the flow stress-strain curves. Based on the experimental data, modified constitutive models were developed, and the suitability of Johnson-Cook（JC） and Arrhenius flow stress models to the studied steel was discussed. The results indicate that the modified constitutive models are more accurate in predicting the flow stress. The modified JC model is more accurate under high strain rate conditions, while the Arrhenius model is more accurate at low strain rate conditions. The values of experimental load and predicted load show a good agreement, indicating that the developed model is adequate to describe the flow behavior of the steel.