Low-temperature slab-reheated grain-oriented silicon steel is characterized by a sharp{411}<148> primary recrystallization texture.To date,the influence of this texture on secondary recrystallization is not clea...Low-temperature slab-reheated grain-oriented silicon steel is characterized by a sharp{411}<148> primary recrystallization texture.To date,the influence of this texture on secondary recrystallization is not clear.Microtextures in primary and secondary recrystallized sheets of low-temperature reheated grain-oriented silicon steel were examined using electron backscatter diffraction.By comparing the textures and microstructures of specific primary recrystallized grains neighboring secondary grains with those of other primary grains,the influences of primary recrystallization textures and microstructures on the orientations of secondary grains were investigated.Results show that for low-temperature reheated grain-oriented silicon steel,the primary recrystallization sheet comprises {411}<148>,{111}<112>,and{001}<120> texture components.During secondary recrystallization,the{111}<112> primary recrystallized grains were easily consumed by abnormally grown Goss,deviated Goss,Brass,or{210}<001>grains;the{411}<148> primary recrystallized grains were more resistant to being swallowed;and the{001}<120>grains were the most resistant to being consumed.For a particular primary grain,the distribution of its surrounding grain boundaries determined how easily it is consumed during secondary recrystallization.Primary grains surrounded by 20°-45°grain boundaries were consumed much earlier than those having grain boundaries above 45°,which is in accordance with high-energy grain boundary theory.In addition,special Σ9 boundaries between {411}<148> and Goss grains move more slowly than Σ9 boundaries between{111}<112>and Goss grains,which is attributed to the different positions of<110> rotation axis with respect to the normals of grain boundaries.展开更多
The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental resul...The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental results showed that in the multiphase microstructure of the investigated steel when the finish rolling temperature was about 820 ℃ and the final air cooling temperature was in the range of 630-700 ℃, the grain size of most of ferrite was finer (about 4 μm) and which had higher dislocation density, the bainite packets had chaotic orientations and lath boundaries of bainite were not quite straight, the retained austenite distributed in the ferrite grain boundaries or triradius was fine and dispersive, and their grain size was about 0.4-1.9 μm. With increasing the amount of ferrite, the volume fraction of retained austenite had a slight decrease. When the final air cooling temperature was 630 ℃, the steel had excellent mechanical properties, which was characterized by combination of continuous yielding, high strength (about 796 MPa) and high elongation (22.7%) as well as low yield/strength ratio (0.58); when the final air cooling temperature increased to 700 ℃, the matrix structure was bainite packets and the comprehensive properties were deteriorated.展开更多
基金Item Sponsored by National High Technology Research and Development Program of China(2012AA03A505)
文摘Low-temperature slab-reheated grain-oriented silicon steel is characterized by a sharp{411}<148> primary recrystallization texture.To date,the influence of this texture on secondary recrystallization is not clear.Microtextures in primary and secondary recrystallized sheets of low-temperature reheated grain-oriented silicon steel were examined using electron backscatter diffraction.By comparing the textures and microstructures of specific primary recrystallized grains neighboring secondary grains with those of other primary grains,the influences of primary recrystallization textures and microstructures on the orientations of secondary grains were investigated.Results show that for low-temperature reheated grain-oriented silicon steel,the primary recrystallization sheet comprises {411}<148>,{111}<112>,and{001}<120> texture components.During secondary recrystallization,the{111}<112> primary recrystallized grains were easily consumed by abnormally grown Goss,deviated Goss,Brass,or{210}<001>grains;the{411}<148> primary recrystallized grains were more resistant to being swallowed;and the{001}<120>grains were the most resistant to being consumed.For a particular primary grain,the distribution of its surrounding grain boundaries determined how easily it is consumed during secondary recrystallization.Primary grains surrounded by 20°-45°grain boundaries were consumed much earlier than those having grain boundaries above 45°,which is in accordance with high-energy grain boundary theory.In addition,special Σ9 boundaries between {411}<148> and Goss grains move more slowly than Σ9 boundaries between{111}<112>and Goss grains,which is attributed to the different positions of<110> rotation axis with respect to the normals of grain boundaries.
基金Fundamental Research Funds for the Central Universities (N090407001)National Key Project of Scientific and Technical Supporting Programs(2007BAE51B07)National Natural Science Foundation of China (50734001)
文摘The effects of final air cooling temperature on the microstructure and mechanical properties of hot rolled 0.2C-1.9Mn-0.5Si-0.08P TRIP steel were studied by utilizing OM, SEM, TEM and tensile tests. Experimental results showed that in the multiphase microstructure of the investigated steel when the finish rolling temperature was about 820 ℃ and the final air cooling temperature was in the range of 630-700 ℃, the grain size of most of ferrite was finer (about 4 μm) and which had higher dislocation density, the bainite packets had chaotic orientations and lath boundaries of bainite were not quite straight, the retained austenite distributed in the ferrite grain boundaries or triradius was fine and dispersive, and their grain size was about 0.4-1.9 μm. With increasing the amount of ferrite, the volume fraction of retained austenite had a slight decrease. When the final air cooling temperature was 630 ℃, the steel had excellent mechanical properties, which was characterized by combination of continuous yielding, high strength (about 796 MPa) and high elongation (22.7%) as well as low yield/strength ratio (0.58); when the final air cooling temperature increased to 700 ℃, the matrix structure was bainite packets and the comprehensive properties were deteriorated.
