OS11W0016 Effect of ferritic-austenitic phase fraction on corrosion fatigue behavior in stainless steels

Abstract

Fatigue tests have been conducted in 3%NaCl solution using stainless steels in order to understand the effect of volume fraction of ferritic(α)/austenitic(γ) phase on crack initiation and growth behavior. Materials with five different volume fractions of α/γ phase were prepared. Fatigue cracks were initiated predominantly from slip bands within J grains regardless of volume fraction of α/γ phase. In all the materials, fatigue strengths were slightly reduced in 3%NaCl solution compared with in laboratory air. In very small crack region following crack initiation, crack growth was enhanced in 3%NaCl solution. Environmental effect was also seen in high ΔK region for long cracks, where crack growth rates werefaster in 3%NaCl solution than in laboratory air.