| The properties of stainless steel used on railway wagon are closely related to their microstructures and recrystallization textures. Many efforts have been made to improve materials properties through microstructure and texture control. The addition of Nb-Ti which is an effective way to fix interstitial elements such as C and N, is expected to have remarkable effects on the formation and development of recrystallized microstructures and textures, and thus the deep draw-ability of steel sheets.In this paper, casting steel sheets with different Nb-Ti contents were hot rolled, cold rolled and annealed, respectively. The microstructure observation and texture measurement were performed for various specimens by optical microscope and X-ray method, and the effects of microalloying elements of Nb-Ti on properties were then discussed.The results showed that:(1)The addition of Nb-Ti had obvious effects on microstructure refinement in casting, hot rolled, and annealed sheets. The refining effct of Nb was much stronger than Ti, and the effect of Nb-Ti was best. (2) The addition of Nb elements had strongly restrained recrystallization during hot rolling and annealing process. (3)Nb was benefit for improving the intensity of materials, while Ti played a distinct role in improving elongation percentage.Results of welding simulation with different welding currents indicated that the width of HAZ was broadened with the increasing of the welding current. With the addition of Ti, the microstructure of HAZ transformed from martensite to ferritic. Ti was more favorable for refining of the microstructure of HAZ, and promoting y fiber texture. |
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