Corrosion Resistance of 13% Chromium Steels as Influenced by Tempering Treatments

The effects of time and temperature of tempering on the resistance to corrosion of α 0·29%C, 13%Cr steel have been investigated. The results are discussed with reference to proposed mechanisms of accelerated corrosion resulting from certain treatments. A mechanism whereby local chromium depletion of the matrix is caused by the growth of chromium-rich carbides is favoured. Results of the testing of steels of varying chromium content in several corrosive media are presented in support of this view.