Simulation study on the thermal stress of W/316L stainless steel first wall material

Abstract

BackgroundDuring the service period of the first wall materials, the thermal stress in the material is one of the key issues restricingt the safety of the fusion reactor.PurposeThis study aims to clarify the influencing factors of thermal stress in the W/316L stainless steel taken as the first wall system of ITER (International Thermonuclear Experimental Reactor).MethodBased on the finite element software Ansys Workbench, the first wall system model of W/316L stainless steel was constructed. The relationship between temperature, coating thickness and substrate thickness and the thermal stress was analyzed. Finally, Cu interlayer was introduced to test the maximum thermal stress in the system.ResultsThe simulation results show that the thermal stress values increase with the increasing of temperature and substrate thickness. However, with the increase of coating thickness, an inverse relationship is found due to the stress relaxation. In addition, the stress mismatch caused by thermal mismatch between W and 316L stainless steel substrate is alleviated by adding Cu interlayer. The maximum thermal stress in the system is reduced from 1 676.3 MPa to 1 507.7 MPa.ConclusionsThis study lays a theoretical foundation for the development of high thermal stability W coating system.

Keywords

• w/316l
• stainless steel first wall system
• thermal stress
• temperature