Hall–Petch Behavior in Ultra-Fine-Grained AISI 301LN Stainless Steel

Abstract

An ultra-fine-grained AISI 301LN austenitic stainless steel has been achieved by heavy cold rolling, to induce the formation of martensite, and subsequent annealing at 800°C, 900°C, and 1000°C, from 1 to 100 seconds. The microstructural evolution was analyzed using transmission electron microscopy and the yield strength determined by tension testing. Ultra-fine austenite grains, as small as~0.54 lm, were obtained in samples annealed at 800°C for 1 second. For these samples, tensile tests revealed a very high yield strength of~700 MPa, which is twice the typical yield strength of conventional fully annealed AISI 301LN stainless steels. An analysis of the relationship between yield strength and grain size in these submicron-grained stainless steels indicates a classical Hall-Petch behavior. Furthermore, when the yield dependence on annealing temperature is considered, the results show that the Hall-Petch relation is due to an interplay between fine-grained austenite, solid solution strengthening, precipitate hardening, and strain hardening.

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

“…5). Rajasekhara et al 6) reported the grain growth from 0.5 to 2.4 μm within holding from 1 to 10 s at 1 173 K in the 301LN Cr-Ni steel. Therefore, the prevention of grain coarsening or at least retarding it would be beneficial for practical processing.…”

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

“…[4][5][6][7][8] An ultrafine grain size can be obtained by heavy cold deformation to create a high fraction of SIM that during subsequent proper annealing treatment reverts back to austenite. Martensitic reversion has already been investigated and reported during the 1970's, as referred by Tomimura et al 4) They also noted the formation of a fine austenite grain size obtained from reversed martensite in their experimental Cr-Ni steels.…”

Enhanced quasi-static and dynamic shear properties by heterogeneous gradient and lamella structures in 301 stainless steels

“…the TRIP effect, the maraging effect by nano-precipitation and the composite effect due to strain partitioning [11]. Similarly, heterogeneous UFG SS combining with TRIP effect and Lüders bands also exhibited both high strength and good ductility [16][17][18][19]. Recently, several strategies employing hierarchical structures, such as gradient structure (GS) and heterogeneous lamella structure (HLS) [6,[20][21][22][23], have been reported to produce a superior synergy of yield strength and ductility.…”

Effect of Cyclic Thermal Process on Ultrafine Grain Formation in AISI 304L Austenitic Stainless Steel

“…Using the advanced thermomechanical processing route, it was demonstrated that by reverse transformation of straininduced a¢-martensite (SIM) to austenite, it was possible to produce nanocrystalline or ultrafine-grained stainless steel. [12][13][14][15][16][17][18][19][20][21][22][23] This technique involves transformation of metastable austenite to SIM by heavy cold rolling and SIM then reverts to recrystallized austenite grains during subsequent annealing. Recently, an alternative technique of the repetitive thermomechanical process was employed to successfully produce nanostructured stainless steel.…”