Corrosion Behavior of Welded Austenitic Stainless Steel in Different Environments

S O. Aluko; D.S. Yawas; S.Y. Aku

doi:10.3759/joise.v1i3.3494

Abstract

Corrosion behavior of welded austenitic stainless steel in 0.5 M hydrochloric acid and wet-steam corrosive media has been studied. The immersion time in the corrosive media was 30 days to simulate the effect on stainless steel structures/equipment in offshore and food processing applications. Annealing heat treatment was carried out on the samples. The gravimetric technique was used for the corrosion tests. Seawater sample has highest weight loss of 4.0 mg for the heat-treated samples and 4.5 mg for the unheat-treated samples. For the different media used, seawater sample has the highest corrosion rate of 0.64 × 10−6 mm/year for the heat treated samples and 0.72 × 10−6 mm/year for the unheat-treated samples. The post-welding heat treatment was found to increase the mechanical properties of the austenitic stainless steel especially tensile strength but it reduces the transformation and thermal stresses of the samples. These findings were corroborated by the microstructural examination of the stainless steel specimen.