摘要

Hot compression tests of sand casting and centrifugal casting Q235B flange blanks were performed at strain rate range of 0.01-5 s(-1) and temperature range of 850-1,150 degrees C. The evolutions of microstructure and texture were revealed. The constitutive models based on Arrhenius constitutive modeling were proposed by considering the effects of strain on material constants. The results show that recrystallization in centrifugal casting Q235B is more apparent than that in sand casting, resulting in the finer grains and lower flow stress for centrifugal casting Q235B. The intensities of textures slightly weaken with the increase of temperature. At 1,050 degrees C and 5 s(-1), the textures of sand casting are characterized by strong {001}< 100 > and {001}< 110 >, which are related with severe deformation, while the textures of centrifugal casting are composed of {110}< 110 > and {111}< 112 >, which are related with dynamic recovery and shear deformation. A good agreement between the predicted and experimental flow stress is achieved and demonstrates that the proposed constitutive models are reliable.