Effect of Chromium Depleted Surface On Corrosion Behavior of Type 430 Stainless Steel Available to Purchase

Loss of chromium during steel mill processing is discussed together with the effect of this chromium depleted surface on atmospheric corrosion. A bench test for rapidly identifying the presence of chromium depleted surface is described and correlated with outdoor exposure tests. From laboratory studies cited several methods of overcoming this chromium depleted condition in Type 430 stainless steel are apparent. These methods include the use of a longer annealing cycle, a more complete pickling treatment after each high speed anneal, and mechanical abrasion of the surface. 8.8.5