To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scan...To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.展开更多
The texture evolution,twin crystallographic nature and grain orientation variation during the solution heat treatment process of the 304 stainless steel pipe were studied.It was found that after the solution heat trea...The texture evolution,twin crystallographic nature and grain orientation variation during the solution heat treatment process of the 304 stainless steel pipe were studied.It was found that after the solution heat treatment,the texture type clearly changed,and the texture strength was greatly increased.During the solution heat treatment process,grain boundaries migrated along the orientation available for grain growth,giving rise to abnormal growth of some grains through merging with the adjacent small grains.After the solution heat treatment,more<111>60°twins formed in the microstructures of the 304 stainless steel pipe,and the fraction of the twin boundaries showed a pronounced increase.Analysis of the twin crystallographic nature of the FCC crystals showed that four kinds of twin variants can be formed within austenite parent grains,and twelve kinds of misorientations can be formed between the austenite parent grains and the secondary twins.展开更多
基金Project(2009D005002000003) supported by the Foundation for Fostering Outstanding Talents of Beijing,China
文摘To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.
基金Project(51875547)supported by the National Natural Science Foundation of China。
文摘The texture evolution,twin crystallographic nature and grain orientation variation during the solution heat treatment process of the 304 stainless steel pipe were studied.It was found that after the solution heat treatment,the texture type clearly changed,and the texture strength was greatly increased.During the solution heat treatment process,grain boundaries migrated along the orientation available for grain growth,giving rise to abnormal growth of some grains through merging with the adjacent small grains.After the solution heat treatment,more<111>60°twins formed in the microstructures of the 304 stainless steel pipe,and the fraction of the twin boundaries showed a pronounced increase.Analysis of the twin crystallographic nature of the FCC crystals showed that four kinds of twin variants can be formed within austenite parent grains,and twelve kinds of misorientations can be formed between the austenite parent grains and the secondary twins.
