Determination of Corrosion Rates in Hot, Concentrated Sulfuric Acid

Abstract Weight-loss experiments with UNS S31008 (AISI 310S) stainless steel in hot, concentrated sulfuric acid (H2SO4) are used to demonstrate the difficulties that can be encountered in the laboratory in determining corrosion rates relevant to field experience. It is shown that when samples are tested in finite volumes of acid a buildup of dissolved ions reduces the actual corrosion rate with time. Consequently, care should be taken in adopting published corrosion rates as being relevant to field exposure in typical flowing acid systems where the accumulation of corrosion products is often minimal.