For preparing large-scale nano-grained and ultrafine-grained steel sheets by warm rolling and annealing, the effects of deforming temperature on both the flow stress and the microstructure evolution of 09MnNiD steel w...For preparing large-scale nano-grained and ultrafine-grained steel sheets by warm rolling and annealing, the effects of deforming temperature on both the flow stress and the microstructure evolution of 09MnNiD steel with lath martensitic microstructure were studied by warm-compression test and transmission electron microscopy （TEM） observation. Thereafter, the steel with the lath martensitic structure was multi-pass warm-rolled and then annealed. TEM results indicate that nano-grained and ultrafine-grained steel sheets are formed by warm rolling at 400℃ and annealing at 400-600℃. In comparison with the as-warm-rolled specimen, the tensile strength at room temperature changes a little when the rolled samples are annealed below 450℃, and the tensile strength is greatly lowered as the annealing temperature increases to above 550℃.展开更多
To improve the oxidation resistance property of iron fibers, a SiO2 coated iron fiber was prepared by sol-gel method, and its microstructure, element and phase composition, antioxidation property, and crystallization ...To improve the oxidation resistance property of iron fibers, a SiO2 coated iron fiber was prepared by sol-gel method, and its microstructure, element and phase composition, antioxidation property, and crystallization were characterized by scanning electron microscopy, thermal gravimetric analysis, X-ray diffraction and 3% CuSO4 solution dripping. It was found that the surface of the iron fiber can be fully covered with SiO2 by using Sol-Gel method. Our results also indicated that the time of iron begin to be corrupted in 3% CuSO4 solution drip increased from 30 s to 240 s, and the temperature increased from 200?C to 310?C. In addition, the oxidation and antioxidation mechanisms of the SiO2 coated iron fiber have also been discussed in this work.展开更多
基金the National Natural Science Foundations of China(Nos.50271060 and 50371074)the Natural Science Foundation of Hebei Province,China(No.503291).
文摘For preparing large-scale nano-grained and ultrafine-grained steel sheets by warm rolling and annealing, the effects of deforming temperature on both the flow stress and the microstructure evolution of 09MnNiD steel with lath martensitic microstructure were studied by warm-compression test and transmission electron microscopy （TEM） observation. Thereafter, the steel with the lath martensitic structure was multi-pass warm-rolled and then annealed. TEM results indicate that nano-grained and ultrafine-grained steel sheets are formed by warm rolling at 400℃ and annealing at 400-600℃. In comparison with the as-warm-rolled specimen, the tensile strength at room temperature changes a little when the rolled samples are annealed below 450℃, and the tensile strength is greatly lowered as the annealing temperature increases to above 550℃.
文摘To improve the oxidation resistance property of iron fibers, a SiO2 coated iron fiber was prepared by sol-gel method, and its microstructure, element and phase composition, antioxidation property, and crystallization were characterized by scanning electron microscopy, thermal gravimetric analysis, X-ray diffraction and 3% CuSO4 solution dripping. It was found that the surface of the iron fiber can be fully covered with SiO2 by using Sol-Gel method. Our results also indicated that the time of iron begin to be corrupted in 3% CuSO4 solution drip increased from 30 s to 240 s, and the temperature increased from 200?C to 310?C. In addition, the oxidation and antioxidation mechanisms of the SiO2 coated iron fiber have also been discussed in this work.
