The effect of cold rolling reduction(50%-90%)on the grain structures of solutionized 1445 Al-Li alloy sheet at525-575 ℃ was investigated through electron backscatter diffraction(EBSD).Although the solutionization tem...The effect of cold rolling reduction(50%-90%)on the grain structures of solutionized 1445 Al-Li alloy sheet at525-575 ℃ was investigated through electron backscatter diffraction(EBSD).Although the solutionization temperature is elevated to 575 ℃,the sheet is not completely recrystallized.The main recrystallization model is subgrain coalescence and growth,and the non-recrystallization is due to the formed nano-sized Al3(Sc,Zr)dispersoids,which pin the grain boundaries,subgrain boundaries and dislocations.With increasing the cold rolling reduction,the fraction and size of the recrystallized grains in the sheet solutionized at525 ℃ are decreased,but the fraction of the subgrains is increased,leading to a decrease in the fraction of the deformed structures.Meanwhile,the number fraction of high-angle boundaries(HABs)is increased.Due to the decreased fraction of the deformed structures and increased fraction of the HABs,the T8-aged 1445 Al-Li alloy sheet displays a decrease trend in the strength and heterogeneity with increasing the cold rolling reduction.At higher solutionization temperature of 575 ℃,the fraction of the recrystallized grains and their size are obviously increased.展开更多
The influence of cold rolling reduction on microstructure and mechanical properties of the TWIP （ttwinning induced plasticity） steel was investigated. The results＇ indicated that the steel had better comprehensive ...The influence of cold rolling reduction on microstructure and mechanical properties of the TWIP （ttwinning induced plasticity） steel was investigated. The results＇ indicated that the steel had better comprehensive mechanical properties when cold rolling reduction was about 65.0% and the annealing temperature was 1000℃. The tensile strength of the steel is about 640MPa and the yield strength is higher than 255MPa, while the elongation is＇ above 82%. The microstructure is composed of austenitic matrix and annealing twins at room temperature, at the same time, a significant amount of annealing twins and stacking faults＇ are observed by transmission electron microscopy （TEM）. Mechanical twins play a dominant role during deformation, and result in exceUent mechanical properties.展开更多
Two kinds of cold rolling experiments, single cold rolling and double cold rolling, were carried out on one titanium stabilized interstitial free (IF) steel that has been warm rolled at ferrite temperature. The main a...Two kinds of cold rolling experiments, single cold rolling and double cold rolling, were carried out on one titanium stabilized interstitial free (IF) steel that has been warm rolled at ferrite temperature. The main aim was to investigate the evolution of rolling and annealing textures from the well known behavior observed under single cold rolling condition to the less understood double cold rolling by using orientation distribution function (ODF). In the twice cold rolled samples, the annealing texture comprises only single {111}(110-112) r-fibre texture when it subjected to moderate reduction in the first round of rolling. Accordingly both the once cold rolled sample and the twice cold rolled sample with heavy reduction in the first round of rolling have much complex texture components. They are related to the formation of initial {111} subgrain and the priority growth of stable {111} nucleus.展开更多
文摘The effect of cold rolling reduction(50%-90%)on the grain structures of solutionized 1445 Al-Li alloy sheet at525-575 ℃ was investigated through electron backscatter diffraction(EBSD).Although the solutionization temperature is elevated to 575 ℃,the sheet is not completely recrystallized.The main recrystallization model is subgrain coalescence and growth,and the non-recrystallization is due to the formed nano-sized Al3(Sc,Zr)dispersoids,which pin the grain boundaries,subgrain boundaries and dislocations.With increasing the cold rolling reduction,the fraction and size of the recrystallized grains in the sheet solutionized at525 ℃ are decreased,but the fraction of the subgrains is increased,leading to a decrease in the fraction of the deformed structures.Meanwhile,the number fraction of high-angle boundaries(HABs)is increased.Due to the decreased fraction of the deformed structures and increased fraction of the HABs,the T8-aged 1445 Al-Li alloy sheet displays a decrease trend in the strength and heterogeneity with increasing the cold rolling reduction.At higher solutionization temperature of 575 ℃,the fraction of the recrystallized grains and their size are obviously increased.
基金the National Natural Science Foundation of China （No. 50575022） Specialized Research Foundation for the Doctoral Program of Higher Education （No. 20040008024）.
文摘The influence of cold rolling reduction on microstructure and mechanical properties of the TWIP （ttwinning induced plasticity） steel was investigated. The results＇ indicated that the steel had better comprehensive mechanical properties when cold rolling reduction was about 65.0% and the annealing temperature was 1000℃. The tensile strength of the steel is about 640MPa and the yield strength is higher than 255MPa, while the elongation is＇ above 82%. The microstructure is composed of austenitic matrix and annealing twins at room temperature, at the same time, a significant amount of annealing twins and stacking faults＇ are observed by transmission electron microscopy （TEM）. Mechanical twins play a dominant role during deformation, and result in exceUent mechanical properties.
文摘Two kinds of cold rolling experiments, single cold rolling and double cold rolling, were carried out on one titanium stabilized interstitial free (IF) steel that has been warm rolled at ferrite temperature. The main aim was to investigate the evolution of rolling and annealing textures from the well known behavior observed under single cold rolling condition to the less understood double cold rolling by using orientation distribution function (ODF). In the twice cold rolled samples, the annealing texture comprises only single {111}(110-112) r-fibre texture when it subjected to moderate reduction in the first round of rolling. Accordingly both the once cold rolled sample and the twice cold rolled sample with heavy reduction in the first round of rolling have much complex texture components. They are related to the formation of initial {111} subgrain and the priority growth of stable {111} nucleus.
