STAINLESS‐STEEL CORROSION BY DILUTE NITRIC ACID: at Elevated Temperatures and Pressures

Stainless steel has been found to exhibit passivity in dilute nitric acid at 300°C. The rate of corrosion for passive conditions is unaffected by increase in temperature or small quantities of oxidising ions, but is increased in the presence of 10 g./l. of uranium. Corrosion in the vapour phase was found to be insignificant, though severe corrosion occurs at the vapour‐liquid interface. A weight‐loss technique has been used for the bulk of the determinations, but an alternative electrochemical method of investigating the corrosion has been studied with encouraging results.