Simulation and Optimization of High Temperature Creep property of High Performance Ferritic Stainless Steel

Xiuru FAN ^1*, Bernd KUHN ²

¹ Material Digital R&D Center, China Iron & Steel Research Institute Group, Beijing, 10008, China；

² Microstructure and Properties of Materials (IEK-2), Institute of Energy and Climate Research (IEK), Forschungszentrum Jülich, Juelich, 52425, Germany.

ABSTRACT: Fully ferritic, laves phase strengthened, stainless steels with a chromium content of 17 wt.-% (HiperFer, developed in IEK-2, Fz-Juelich) show sufficient resistance to steam oxidation at high temperatures. This class of steel is designed for applying in the next generation of super critical thermal power conversion systems as structure material. Creep behaviour at 650 ^oC is one of the most important properties to determine the performance of candidate materials for such application. However, standard creep property characterization might take thousands of hours for each single test, such tests are time costing and thus expensive. At the same time, initial testing parameters can only be settled by “scientific assumption” derived from practical experiences, which might lead to wrong testing results and even testing failures. Therefore, a simulation tool was considered more effective and economic to evaluate the creep behaviour.

Presented research discusses the interrelation between key factors of creep properties of HiperFer. By understanding the interrelationship of these, creep behaviour of a HiperFer steel could be efficiently evaluated by mathematical simulation. Combining with practical experiments for parameters adjusting, creep simulation could greatly contribute to the optimization of material performances.

Figure 1. Minimum creep rate of HiperFer steels at different operation creep stress.

Keywords: creep; creep simulation; high temperature steel.