多元稀土钨线材轧制致密化及退火分析

Densification and Annealing Analysis of Multi-rare Earth Tungsten Wire Rolling

通过使用二辊轧机,采用一火八道次的热轧制工艺进行多元稀土钨合金线材开坯,对开坯后的多元钨合金线材进行退火处理。利用扫描电子显微镜(SEM)、能谱、光学显微镜、显微硬度计等表征分析轧制致密化过程,轧制、退火对钨线材组织性能的影响。研究结果表明:轧制过程中烧结孔发生变形、闭合,最终在剪切力的作用下消失,多元稀土钨线材密度增加,在轧制温度1650℃,保温时间30min,轧制速度170m/s下进行轧制,孔隙度由6.50%减少至4.61%,钨线材密度由17.84g/cm3增加到18.12g/cm^3;轧制组织中的晶粒在轧制方向上伸长,形成相互挤压、重叠的加工态组织,热轧过程主要发生动态回复过程,在晶粒内部形成胞状亚结构;在1100℃至1300℃退火保温时仅发生回复并未再结晶,在1400℃保温60min发生再结晶,晶粒未完全长大,在1600℃退火保温60min时,再结晶过程完成。

By using a hot two-roll mill,the multi-rare rare earth tungsten alloy wire was opened by a hot rolling process,and the multi-tungsten alloy wire after the rolling was annealed.The effects of rolling densification,rolling and annealing on the microstructure and properties of tungsten wire were analyzed by scanning electron microscope(SEM),energy spectrum,optical microscope,and micro-hardness tester.The results indicate that the sintered holes were deformed and closed during the rolling process,and finally disappears under the action of shearing force.The density of the multi-rare earth tungsten wire increases at the rolling temperature of 1650℃,the holding time of 30 min,and the rolling speed of 170 m/s,the sintered porosityθis reduced from 6.50%to 4.61%,and the tungsten wire density is increased from 17.84 to 18.12 g/cm3.The grains in the rolled structure are elongated in the rolling direction to form a mutual squeeze pressed and overlapped processed microstructures,the hot rolling process mainly occurs in the dynamic recovery process to form a cellular substructure inside the grains;When it is annealed at 1100 to 1300℃,only recovery occurs and no-recrystallization occurs.The recrystallization occurs at 1400℃for 60 min,and the recrystallized grains did not grow completely.The annealing process was completed after annealing at 1600℃for 60 min.