The influence of hot band annealing on recrystallization kinetics and texture evolution in a cold-rolled Nb-stabilized f
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-rolled Nb-stabilized ferritic stainless steel samples were produced with and without annealing. The samples were then cold rolled and isothermally annealed at 650–1000 °C for 10–14,400 s. The recrystallized volume fraction was quantified using the Johnson–Mehl–Avrami–Kolmogorov model and by measuring the microhardness of samples annealed for various duration. The texture evolution was analyzed using electron backscatter diffraction. The calculated Avrami exponents were between 0.8 and 1.2. The intensity of the {111}h121i and {111}h011i components of the c-fiber increased and the deformation texture seen in the a-fiber decreased with increasing annealing time. The intensity of the rotated-cube component decreased with increasing annealing time. The intensity distributions of the early nucleation and full recrystallization textures were noticeably different. The {554}h225i texture component, which was associated with the largest grains, appeared during the late stages of recrystallization. The final annealing led to a grain refinement with a final average grain diameter of 8 lm. I. INTRODUCTION
The high chromium content, addition of alloying elements such as niobium and titanium, and the reduction of the interstitial elements, viz. carbon and nitrogen (C, N), give high corrosion and thermal fatigue resistance, good mechanical strength, and good weldability for ferritic stainless steels.1–3 Nb-stabilized steel AISI 430 has better weldability and formability than that of nonstabilized grades owing to the formation of Nb carbonitrides evenly distributed throughout the ferritic matrix.1,2 In contrast with austenitic stainless steels, the ferritic ones present a lower production cost, due to the absence of nickel as an alloying element. Further, such steels have higher yield strength, lower strain hardening exponent, but lower ductility when compared to austenitic stainless steels.1,4 Several studies about microstructure and crystallographic texture of ferritic stainless steels have been conducted in recent decades to improve the mechanical properties of such steels, especially their behavior in deep drawing, and to eliminate or reduce the formation of stretch marks, aiming to improve the postforming surface finish.4–9 Yazawa et al. postulated that newly developed ferritic stainless steel sheets could be applied in a wide range of automotive parts and in applications requiring Contributing Editor: Jürgen Eckert a) Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2016.296
corrosion resistance and deep drawability, where anticorrosive austenitic stainless steel SUS304 has previously been used.3 “Crystallographic texture” refers to generating a preferential orientation after plastic deformation, recrystallization, and processing.11,13 Metal recrystallization may generate a different preferred crystallographic orientation than plastic deformation does or it may not generate any preferential texture. 10,11 The mechanical behavior of polycrystalline materials is considerably affected by thei
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