声双折射法研究再结晶退火处理对45#钢微观组织的影响

The influences of recrystallization annealing on microstructure of 45 type steel by acoustic birefringence

本文在研究超声测试应力的过程中为了减小材料组织结构以及残余应力对应力测试结果的影响,对45#钢试样进行再结晶退火热处理,并用超声双折射法研究试样的再结晶退火组织,分析其微观组织和各向异性。实验结果表明,试样中横波声速随其偏振化方向改变而变化,存在声速快轴和慢轴且两者相互垂直;试样经650℃炉温,保温40分钟炉冷再结晶退火热处理后,声各向异性因子小,表现出材料微观组织均匀,晶粒细,各向异性小,并与金相实验结果一致。

In the process of stress measurement by acoustic birefringence, specimens of 45 type steel are subjected to recrystallization annealing treatment so that homogeneous microstructure can be acquired and residual stress can be eliminated. The recrystallization annealing textures of specimens are analyzed by acoustic birefringence and coefficients of acoustic anisotropy are measured. Experimental resuks show that shear wave＇s velocities change with polarized direction of the waves. The fast and slow velocity axes perpendicular to each other exist in specimens. Furthermore, the axial directions change with the annealing temperature. The minimal coefficient of shear wave anisotropy is acquired by annealing at 650℃ for 40 minutes. The results of metallographic experiments also show that homogenous microstructure and fine crystal particle appear in the annealed specimens.