Thermal Stability Study of Ultrafine Grained 304L Stainless Steel Produced by Martensitic Process

Gas tungsten arc welding and friction stir welding of ultrafine grained AISI 304L stainless steel: Microstructural and mechanical behavior characterization

“…Because of the excess stored energy in the grain boundaries of UFG 304L stainless steel, this material tends to exhibit grain growth during the heating cycle of FSW [42]. As stated previously, our observation shows that the grain size in the front of the rotating pin and before the occurrence of dynamic recrystallization is not the same as the base metal.…”

“…ACCEPTED MANUSCRIPT 20 to more accurately calculate the activation energy, the actual grain size obtained by EBSD was used in Eq. 8.…”

Effect of Nb Microalloying on Reversion and Grain Growth in a High-Mn 204Cu Austenitic Stainless Steel

“…6,7,15) Therefore, for a more robust annealing stage, the prevention or retardation of grain growth becomes important.…”

“…Higher exponents are found in the literature, for instance for an Fe-22Mn-0.6C steel, n ≈ 3.5 has been reported. 39) Sabooni et al 15) determined the grain growth exponent of 4.8 for reversion-treated ultrafine-grained 304L steel, decreasing with increasing annealing temperature. As discussed by them, nanocrystalline materials can show exponents up to 10.…”

“…41) In fact, the reported experimental activation energies vary in a wide range 280-420 kJ/mol for type 321 and 347 austenitic stainless steels 21,42) and 455 kJ/mol for 304L. 15) Steels 321 and 347 contain stable TiC and NbC carbides, respectively, which create back-stress on grain boundaries hindering their motion, and they thereby increase the activation energy for grain growth. 38,43,44) This can be assumed to be the situation in the present steels, too.…”