Abstract
The performance of various materials used for solving the basic corrosion problems of the pulp and paper industry is well documented in the open literature. Materials used in equipment and components cover the wide spectrum from non-metallic (brick and tile linings with chemical-resistant mortar, thermal resin linings and reinforced thermal resin equipment and pipe) to carbon steel, 900 series standard stainless steels, superaustenitic stainless steels, duplex stainless steels, titanium and alloys of the Ni-Cr-Mo family. The already high corrosivity of the acidic chloride and oxidizing media of this industry has been further aggravated by the need for compliance with environmental regulations. Recycling and closed loop operation of the processes have resulted in higher chloride levels, lower pH-values and higher temperatures. This has created the need to find newer and better cost-effective materials to combat both corrosion and erosion. This paper describes already established 6 Mo stainless steels, and introduces three new alloys which show excellent resistance to pitting and crevice attack in acidic chloride media - one of the main concerns of the pulp and paper industry. One of these three new alloys has exceptional erosion resistance as well as good corrosion resistance.
