Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain r...Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain rate range were determined using nephogram maps of dynamic recrystallization fraction,average grain size,and grain distribution standard deviation.Processing maps at true strains from 0.4 to 0.9 were generated based on flow stress curves to identify the strain corresponding to optimal microstructure homogenization efficiency at various temperatures and strain rates.Results show that within the optimal parameter range,under the conditions of 1150℃ and 0.01 s^(-1),the true strain of about 0.6 results in the optimal microstructure homogenization efficiency.The grain orientation spread maps obtained from the experiment also confirms this conclusion.This study provides an effective method for microstructure homogenization control of GH4706 alloy and an effective reference for the minimum strain threshold of the local part of the forging in engineering.展开更多
In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backsca...In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backscatter diffraction(EBSD)microstructural characterization.The findings suggest that increasing hot compression temperature(T)and reducing strain rate(ε)enhance the degree of dynamic recrystallization(DRX),significantly reducing flow stress and weakening texture intensity.Increasing strain(ε)promotes DRX,with the overall texture strength initially increasing before decreasing.During hot compression at 1000−1100℃,discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twin-induced dynamic recrystallization(TDRX)jointly influence texture development.Among these,DDRX plays a dominant role,with numerous DDRX grains exhibiting dispersed orientations,significantly contributing to texture weakening.The CDRX mechanism induces a limited number of randomly oriented grains within the deformed grains,and its contribution to texture weakening is enhanced with increasingεand decreasing T.The TDRX mechanism generates DRX grains withinΣ3 twin boundaries deviating from their theoretical orientation,and these grains inherit the twin orientation,exerting a limited effect on texture weakening.These findings provide a theoretical foundation for a deeper understanding of DRX behavior and texture evolution in the GH 4706 during hot working.展开更多
基金National Key R&D Program Project(2022YFB3705103)。
文摘Hot compression tests for GH4706 alloy were performed at a true strain of 1.2 within the temperature range of 950-1150℃ and the strain rate range of 0.001-1 s^(-1).The optimal hot deformation temperature and strain rate range were determined using nephogram maps of dynamic recrystallization fraction,average grain size,and grain distribution standard deviation.Processing maps at true strains from 0.4 to 0.9 were generated based on flow stress curves to identify the strain corresponding to optimal microstructure homogenization efficiency at various temperatures and strain rates.Results show that within the optimal parameter range,under the conditions of 1150℃ and 0.01 s^(-1),the true strain of about 0.6 results in the optimal microstructure homogenization efficiency.The grain orientation spread maps obtained from the experiment also confirms this conclusion.This study provides an effective method for microstructure homogenization control of GH4706 alloy and an effective reference for the minimum strain threshold of the local part of the forging in engineering.
基金Project(2022YFB3705103)supported by the National Key R&D Program,China。
文摘In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backscatter diffraction(EBSD)microstructural characterization.The findings suggest that increasing hot compression temperature(T)and reducing strain rate(ε)enhance the degree of dynamic recrystallization(DRX),significantly reducing flow stress and weakening texture intensity.Increasing strain(ε)promotes DRX,with the overall texture strength initially increasing before decreasing.During hot compression at 1000−1100℃,discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twin-induced dynamic recrystallization(TDRX)jointly influence texture development.Among these,DDRX plays a dominant role,with numerous DDRX grains exhibiting dispersed orientations,significantly contributing to texture weakening.The CDRX mechanism induces a limited number of randomly oriented grains within the deformed grains,and its contribution to texture weakening is enhanced with increasingεand decreasing T.The TDRX mechanism generates DRX grains withinΣ3 twin boundaries deviating from their theoretical orientation,and these grains inherit the twin orientation,exerting a limited effect on texture weakening.These findings provide a theoretical foundation for a deeper understanding of DRX behavior and texture evolution in the GH 4706 during hot working.
