Use of a Reducing Melt to Treat the Surface of High-Alloy Steels and Alloys

Abstract

The technological advantages of reducing melts are readily apparent. Such melts can dissolve certain acidic oxides (Si, Mo, W, Ti), and they reduce not only the oxides dissolved in the melt (ferrates, ferrites), but also those on the surface of the steel. A reaction involving sodium hydride completely reduces oxides of iron, nickel, cobalt, and copper and partially reduces oxides of chromium, manganese, vanadium, and titanium. Pickling schemes that have been developed reduce acid consumption and metal loss during pickling and prevent over-pickling of the surface. The technology as a whole is particularly suited for metallurgical plants that produce a wide range of steels.