A Novel Preparartion Method for Lean Duplex Steels

Abstract

Within many areas of the chemical, power and paper industry as well as in oil and petrol production high corrosion resistant steels are used. It is well known that chromium is the key element to enhance the resistance against corrosion attack. Additional alloying elements like nickel, molybdenum, manganese and/or nitrogen are used to change the lattice structure and to improve mechanical and/or chemical properties. During the last years the commodity price of nickel and molybdenum is significantly increased. Consequently, steels with low nickel and molybdenum content have been developed. The so-called lean duplex steels like LDX 2101 (X2CrMnNiN22-5-2) and SAF 2304 (X2CrNiN23-4) are a good substitute for high alloyed austenitic stainless steels.In order to obtain information about the microstructural changes of lean duplex steels after a heat treatment at 475 °C and 700 °C, which has a great influence on mechanical and chemical properties (Fig. 2). Such a surface condition does not allow for any electron back scatter diffraction (EBSD) investigations. The newly developed preparation method listed in Tab.