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A quenching–tempering–partitioning (Q–T–P) process was performed on a Fe-13Cr-3Ni-2Cu-0.1C alloy to investigate the effect of the partitioning process on the reversed austenite and mechanical properties. A quenching and tempering (Q–T) process was also carried out for comparison. The amount and characteristics of the reversed austenite were studied with XRD and TEM. The results showed that the volume fraction of reversed austenite in the Q–T–P-treated samples was higher than that in the Q–T-treated ones. Finer film-like and blocky austenite formed in the Q–T–P-treated samples, and fine Cu-rich precipitates were also well distributed in the matrix. However, wide band and blocky austenite formed in the Q–T-treated samples. Hence, the Q–T–P-treated samples had better comprehensive mechanical properties than the Q–T-treated ones. [ABSTRACT FROM AUTHOR]

In order to increase the hot workability and provide proper hot forming parameters of forging Z12CN13 martensite stainless steel for the simulation and production, the static recrystallization behavior has been studied by double-pass hot compression tests. The effects of deformation temperature, strain rate and inter-pass time on the static recrystallization fraction by the 2% offset method are extensively studied. The results indicate that increasing the inter-pass time and the deformation temperature as well as strain rate appropriately can increase the fraction of static recrystallization. At the temperature of 1050-1150 °C, inter-pass time of 30-100 s and strain rate of 0.1-5 s, the static recrystallization behavior is obvious. In addition, the kinetics of static recrystallization behavior of Z12CN13 steel has been established and the activation energy of static recrystallization is 173.030 kJ/mol. The substructure and precipitates have been studied by TEM. The results reveal that the nucleation mode is bulging at grain boundary. Undissolved precipitates such as MoNi and FeC have a retarding effect on the recrystallization kinetics. The effect is weaker than the accelerating effect of deformation temperature. [ABSTRACT FROM AUTHOR]

The nuclei orientation, the nucleation site at the early stage of recrystallization, and the growth mechanism of the nuclei have been studied by EBSD analysis in Ti-IF steel during direct annealing after warm rolling. It is concluded that the formation of the recrystallization texture is dominated by the oriented nucleation mechanism. The recrystallized nuclei with γ-orientation emerged preferentially at the beginning of recrystallization and preferred to form in the deformed bands with γ-orientation and on the boundaries between γ- and α-orientations. The recrystallized grains first consumed their neighboring γ-oriented matrix; and then consumed the α-oriented deformed bands at the late stage of recrystallization, leading to strong γ-fiber. [ABSTRACT FROM AUTHOR]

The texture characteristics and the recrystallization mechanism during annealing in warm rolled and subsequently cold rolled Ti-IF steel have been investigated by x-ray diffraction and electron backscattered diffraction (EBSD). The results attained by x-ray show that texture changes little until the holding time reaches 4 h. After annealing for 4 h, the orientation density of α-fiber reduces dramatically, but the orientation density of γ-fiber has no obvious change; however, the density of {332}〈113〉 component increases. The EBSD analysis shows that orientated-nucleation dominates during recrystallization, and the orientation of the nuclei includes γ-orientation as well as {332}〈113〉 component. [ABSTRACT FROM AUTHOR]