Modelling of materials properties in duplex stainless steels

Work is being undertaken to develop a new multiplatform software programme for predicting a wide range of materials properties for various alloy types. These properties include thermophysical and physical properties, mechanical properties, time-temperature transformation (TTT)/continuous cooling transformation diagrams etc. and the calculations are being applied to a variety of multicomponent alloy types, such as Ni based superalloys, steels, Ti alloys, Al alloys. The current paper concentrates on duplex stainless steels and describes the scientific background used for the calculation of TTT diagrams and mechanical properties for these materials. It is shown that there is very good agreement between the calculated TTT diagrams and the observed results from the literature for the formation of the sigma, chi, and the chromium rich alpha' phase, while the calculated proof stress, tensile stress and hardness are in good agreement with the available experimental data. The effects of solution treatment temperature and the volume fraction of sigma phase on mechanical properties are also discussed.