退火温度对新型锆合金薄板带材析出相和织构的影响

采用扫描电镜和超高分辨透射电镜,对具有良好冲制性能的新型锆合金薄板成品带材进行含晶粒、第二相粒子等在内的显微组织研究,并探索真空退火处理条件下温度对带材显微组织的影响。结果显示:新型锆合金薄板成品带材晶粒平均尺寸2.17 μm,存在{0001}<1010>和{0001}<1120>两种织构,大部分晶粒<1120>平行带材RD方向,较少晶粒<1010>平行带材RD方向;第二相粒子分布在晶粒内部及晶界,平均尺寸114 nm,尺寸较大的为不规则椭圆形的Zr-Nb-Fe相,尺寸较小的为圆形的β-Nb相;热处理退火温度降低,带材晶粒尺寸减小,第二相粒子细小弥散分布;新型锆合金薄板成品带材良好冲制性能主要源于轧制积累应变诱发再结晶过程进行充分,导致晶粒细小及孪晶发生破碎;相对轧制变形,退火对带材冲制性能影响不显著。

Effect of annealing temperature on precipitated phase and texture of new zirconium alloy sheet strip

Microstructure of a new zirconium alloy sheet strip with good punching properties was studied by means of scanning electron microscopy and ultra high resolution transmission electron microscopy,including grain and second phase particles,and to explore the effect of annealing temperatures on the microstructure of strip under vacuum heat treatment.The results show that the average grain size of the finished strip of the new zirconium alloy sheet is 2.17μm.There are two textures of{0001}■and{0001}■.Most of the grains{0001}■parallel strip RD direction,less grain with■parallel strip RD direction.The second phase particles are distributed inside the grain and at the grain boundary,with an average size of 114 nm,a large size is an irregular elliptical Zr-Nb-Fe phase,and a smaller is a circularβ-Nb phase.As the heat treatment annealing temperature decreases,the strip grain size decreases,and the second phase particles are fine and dispersed.The good punching performance of the new zirconium alloy sheet is mainly due to the fact that the rolling accumulating strain-induced recrystallization process is sufficient,resulting in fine grain and broken twins.Relative to rolling deformation,annealing has no significant effect on strip punching performance.