Effects of the grain size on the corrosion behavior of refined AISI 304 austenitic stainless steels

摘要: Although there have been many studies on fine grained ferritic steels, only a few research reports are available refined austenitic stainless steels and, in particular, the influence of grain size corrosion resistance this class material [1, 2]. The can be easily induced by phase transformation, but alloys, following absence diameter is usually controlled recrystallization after cold working [3]. This method mainly affected temperature, amount deformation and temperature. Recrystallization hot rolling reported to effect refining [4] seems limited. In previous paper [5] we examined subzero steels. ultrafine AISI 304 steel ca. 1 μm average was obtained applying reverse transformation martensite austenite subzeroworked annealed at low temperatures. Up now, behavior such ultrafinegrained has not reported. deals with behavior, especially general (GC), intergranular (IGC) pitting (PC) ultrafine-grained steel. Results compared those similar measurements standard chemical composition steel, from commercial batch, shown Table I. After down 90% thickness reduction, subjected four heat treatments order obtain different microstructures: annealing 800 ◦C for 160 s 900 (specimens A B respectively) 1000 10 600 C D respectively). sizes corresponding above specimens, as measured automatic image analyzer, II. typical microstructures 50μm specimens Fig. 1. Tensile properties 2. Ultimate tensile stress 0.2% yield increase decreasing size, according Hall Petch relation [6]. Steel materials were machined into test 15 × mm. specimen surface polished using increasingly finer abrasive papers, starting 300 grit finishing up