PASSIVATING LAYERS FORMED IN NEUTRAL MEDIA ON A FE-CR ALLOY

The modification of the surface oxide on Kh-5 steel by a 0.25% aqueous solution of the IFKhAN-20 inhibitor at 20 - 250 degrees C has been studied. The surface oxide does not undergo dissolution within the whole temperature range, but grows intensely above 150 degrees C. It is shown that the inner side of the metal-oxide interface formed above 70 degrees C is markedly enriched with chromium in comparison to the air-formed oxide. The authors link this fact to the significant increase in the corrosion resistance of the modified alloy under 100% humidity.