DUPLEX STAINLESS STEELS (austenitic-ferritic and 10-13 Cr ferritic-martensitic) Applications, advantages and limitations

摘要

The substantial costs for adequate protection against corrosion of steel structures, pipelines, heat exchangers and pressure vessels are nowadays more and more precisely evaluated by using life cycle cost analysis. In many cases, standard carbon steels and austenitic stainless steels can be successfully replaced by either austenitic-ferritic or ferritic-martensitic (10-13 percent Cr) duplex stainless steels. These alternative materials offer excellent resistance against corrosion, higher mechanical properties leading to lower fabrication costs, and an adequate notch toughness up to low design temperatures (e.g. - 40 deg C for the austenitic-ferritic stainless steels). In this paper, the test results of recent research projects on two stainless steels which are increasingly used in industry are described. Weldability and fracture toughness at low design temperatures have been evaluated by different testing techniques including large scale testing. The findings enhance the confidence for use of these steels in large thicknesses in highly demanding applications.