非线性超声表征HR3C钢时效过程中析出相的变化

研究了HR3C钢在700和750 ℃下时效过程的组织演变,并用非线性超声技术来进行表征。在时效过程中主要析出相为M₂₃C₆和Z相,其总体面积分数和平均直径随着时效时间和温度的增加而增加。用非线性超声技术对时效试样进行测量,试验结果表明,非线性超声系数也随着时效时间和温度的增加而增加,其上升趋势和析出相的总面积分数呈现一定的相关性。这说明非线性超声系数对析出相的变化趋势敏感,可以用来表征HR3C钢时效过程中的微观结构变化。

Precipitated phase change of HR3C steel during aging characterized by nonlinear ultrasonic technique

Microstructure change of HR3C steel during long-term aging at 700 ℃ and 750 ℃ was studied and characterized by nonlinear ultrasonic technique. Test results show that the main precipitated phases are M23C6 and Z-phase during aging,and their total area fraction and average diameter increase with the increase of aging time and temperature. The aged specimens were measured by nonlinear ultrasonic technique. The results show that the nonlinear ultrasonic coefficient increases with the increase of aging time and temperature,and the rising trend is correlated with the total area fraction of the precipitated phases,which indicates that the nonlinear ultrasonic coefficient is sensitive to the change of precipitates and can be used to characterize the microstructure change of HR3 C steel during aging.