Duplex and ferritic stainless steel sheet linings versus weld overlay and other metallic corrosion-resistant barriers

Abstract

Sheet linings made from stainless steel can protect carbon steel substrates at lower initial direct cost for installation and subsequent direct inspection than weld overlay and thermal sprayed coating. Closely matched thermal expansion coefficients of ferritic and duplex stainless steel grades with carbon steel allow large “tile pieces” in reliable, leak-proof linings compared to linings from austenitic grades, simplifying and speeding installation. Sheet linings with ferritic and duplex grades typically have lower unit costs than weld overlay and thermal sprayed coatings. Ferritic and lean duplex grades resist corrosion and stress corrosion cracking in most alkaline pulping and liquor recovery environments. Super-duplex grades can replace acid-resistant brick linings in D-stage bleaching equipment, including pre-retention tubes and towers. Carefully specified sheet linings of ferritic and duplex stainless steels, professionally installed in accordance with longstanding industry standards, are reliable and economical protective barriers, especially compared with weld overlay, in many applications in modern pulp