Precipitation of Secondary Phases in Duplok 27 Duplex Stainless Steel with Emphasis on Copper Effects;Final rept

摘要

Precipitation of intermetallic secondary phases in duplex stainless steel is a well-known weakness of modern highly alloyed grades. Even relative small amounts of these phases can deteriorate severely mechanical and corrosion properties, the properties the duplex stainless steels are famous for. The problem can be handled by appropriate thermal treatment. However, finding and following the optimal treatment routine is challenging for modern industry dealing often with voluminous components and requires a careful separate study for each grade. This report presents the results of the study performed in continuation of the research of modern industrial duplex stainless steels, which has been carried out at the Laboratory of Engineering Materials, Helsinki University of Technology for about a decade. The report is a collection of data on the microstructure, precipitation properties, mechanical and corrosion properties of Duplok 27, a novel grade of super duplex stainless steel designed and manufactured by Metso Oyl by P/M-HIP technology for the needs of the pulp and paper industry.