Study On Thermal Aging Of Duplex Stainless Steel By Atom Probe Tomography

The safe operation of nuclear power plants is the basis of nuclear power development process.It is significant to study the thermal aging process of dual phase stainless steel for nuclear power plant.This paper studies from France,the domestic Y manufacturers and domestic G manufacturers of three kinds of double phase stainless steel material,combined with scanning electron microscopy(SEM),nano hardness tester,impact tester and atom probe tomography(APT),the system analysis of double phase stainless steel long time thermal aging process,mechanical properties,microstructure and atomic spatial distribution evolution;analysis of double phase stainless steel produced by different manufacturers of the macroscopic and microscopic differences.The study of different thermal aging time of the same temperature shows that the hardness of ferrite phase increases significantly with the increase of thermal aging time,and the fracture impact energy decreases sharply,and the material changes from ductile to brittle fracture.The ferrite has a phase decomposition,forming a'alpha and alpha phase,and equiaxed G nucleation growth.There is an obvious segregation of elements/gamma interface,but also the precipitation of G phase.In the vicinity of the phase interface there is no G phase separation region,the characteristics of this region and the characteristics of the ferrite other locations are not the same.The same thermal aging study of dual phase stainless steel produced by different manufacturers shows that the current domestic production has been able to independently produce a dual phase stainless steel in line with international standards.The performance of Y steel manufacturers even better than domestic law.The microstructure of steel produced by different manufacturers have a very big difference,this research for manufacturers to improve production technology has a positive effect.