【摘要】 采用真空自耗电弧熔炼、锻造、β相均匀化处理及水淬、α相热挤压、三道次冷轧、中间退火、冷轧、成品退火等流程制备壁厚为0.57 mm、外径为9.5 mm的Zr-Sn-Nb合金包壳管，研究了成品退火温度（450,490,550℃）对包壳管微观结构和耐腐蚀性能的影响。结果表明：随着成品退火温度升高，Zr-Sn-Nb合金包壳管的晶粒尺寸增大，晶粒由纤维形貌变为再结晶等轴形貌，再结晶等轴晶粒占比由16.4%增大至92.5%，织构由■平行于轴向转变为■平行于轴向。提高成品退火温度未改变析出相的类型，但促进析出相均匀分布和颗粒粗化，其平均尺寸由117.91 nm增大至155.29 nm。随着成品退火温度升高，包壳管的单位面积腐蚀质量增量降低，耐腐蚀性能提高，这主要与再结晶组织导致的氧化膜晶粒粗化，使得腐蚀过程中的O^2-、H⁺、OH^-及电子扩散通道减少有关。更多还原

【Abstract】 Zr-Sn-Nb alloy cladding tubes with a wall thickness of 0.57 mm and an outer diameter of 9.5 mm were fabricated by using a process including vacuum consumable arc melting,forging,β-phase homogenization treatment followed by water quenching,α-phase hot extrusion,three-pass cold rolling,intermediate annealing,cold rolling and final annealing.The effect of final annealing temperature （450,490,550℃）on the microstructure and corrosion resistance of the cladding tubes was studied.The results show that with increasing final annealing temperature,the grain size in the ZrSn-Nb alloy cladding tube increased,and the grain morphology changed from fibrous morphology to recrystallization equiaxed morphology;the proportion of recrystallized grains increased from 16.4%to 92.5%,and the texture changed from ■ parallel to the axial direction to ■ parallel to the axial direction.Increasing final annealing temperature did not change the type of precipitates,but promoted the uniform distribution and coarsening of precipitates;the precipitate average size increased from 117.91 nm to 155.29 nm.With increasing final annealing temperature,the unit area corrosion mass gain of the cladding tube decreased,and the corrosion resistance was improved.This was mainly related to the grain coarsening in oxide films caused by recrystallization structures,which reduced the diffusion channels of O^2-，H⁺,OH^-and electron during the corrosion.更多还原