Effect of grain size on the drawability of the niobium-stabilized ferritic stainless steel ASTM 430
Caio César Caldeira Moura, Reginaldo Pinto Barbosa, Tarcísio Reis de Oliveira
Abstract
Studies were carried out with samples of AISI 430 stainless steel stabilized with niobium produced by direct reduction (just one cold rolling process) to evaluate the effects of grain size on the material deep drawability. Recrystallized samples were heat treated in laboratory to promote the growth of the recrystallized grain. Microstructural characterizations were done by X-ray diffraction for evaluating crystallographic texture, optical microscopy and electron backscatter diffraction (EBSD). The drawability was evaluated by tensile tests for determination of the planar (ΔR) and normal (r) anisotropy coefficients. An increase in the grain size promoted an increase in the intensity of the Gamma fiber (beneficial) and a reduction in the intensity of the Theta fiber (damaging) on the surface of the material’s thickness. At the centerline of the thickness, it was observed that the Gamma fiber’s intensity did not change significantly, and that the Theta fiber’s intensity was reduced. The change of the crystallographic texture, promoted by the increase of grain size, increased the coefficient of anisotropy (r) in all the analyzed directions and decreased the planar anisotropy coefficient.
Keywords
Referências
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Submetido em:
15/10/2019
Aceito em:
09/06/2020
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