锻造温度对Nb521合金棒材组织及力学性能的影响

Effect of Forging Temperature on Microstructure and Mechanical Properties of Nb521 Alloy Bar

在1 000~1 400℃的温度区间对Nb521合金棒材进行拔长锻造,利用显微硬度仪、金相显微镜、拉伸试验机以及超声波探伤仪研究锻造温度对组织和性能的影响。结果表明:锻造温度越高,棒材的动态再结晶比例越高,后续完成再结晶的退火温度越低。随着锻造温度升高至1 400℃,退火态棒材截面上的组织细小均匀,强度和塑性匹配最好。最后,通过棒材的超声波探伤检测,证实了提升锻造温度有利于组织的均匀化,明显降低杂波水平。

Nb521 alloy bars are forged in the temperature range of 1 000-1 400 ℃ . The effects of forging temperature on microstructure and properties are studied by microhardness tester,metallographic microscope,tensile tester and ultrasonic flaw detector.The results show that the higher the forging temperature is,the higher the dynamic recrystallization ratio of the bar is,and the lower the annealing temperature for the subsequent recrystallization.When the forging temperature rises to 1 400 ℃,the microstructure of the annealed bar is fine and uniform,and the strength and plasticity match the best.Besides,it is confirmed by the ultrasonic flaw detection that increasing the forging temperature is beneficial to the homogenization of the microstructure and can significantly reduce the clutter level.