Preparation Of Micro/Nano Structure 2205 Duplex Stainless Steel And Regulation Of Mechanical Properties

2205 Duplex Stainless Steel is materials with a two-phase microstructure composed of austenite and ferrite.Compared with the traditional austenitic stainless steels and high alloyed ferritic steels,the 2205 duplex steel has been widely used in various fields due to its excellent mechanical properties.Microcrystals of nano/microcrystalline increase the dislocation storage space,which makes the work hardening effect can be maintained to a greater strain and the plasticity is better.In addition,the high strength of the material ensured by the nanocrystalline.So the nano/microcrystalline has a good comprehensive mechanical properties.Compared with the traditional method for preparing nano/microcrystalline stainless steel,the aluminothermic reaction method is not only low-cost,low energy consumption,simple process,but also has the potential to amplify industrial production.In this paper,micro-and nanostructured 2205 duplex stainless steels were prepared by the aluminothermic reaction method,which based on the previous work of the research group.It was found in the study when the nanocrystalline 2205 duplex stainless steel is prepared in the large furnace,the material ratio used in the preparation of the small furnace cannot be used.This is due to the loss of Cr when reacting in large furnaces,making the content of Cr in the alloy low.After recalculation,the chemical composition and phase composition of the reaction product meet the design requirements by adding 30% excess Cr element in the reaction mass.Casting defects inside the castings produced by the aluminothermic reaction method result in reduced material properties.Rolling process not only eliminates defects,but also regulates the content and distribution of ferrite and austenite,microcrystalline and nanocrystalline,which will optimize the mechanical properties of the alloy,making it both high strength and high plasticity.Therefore,this paper mainly studied the effect of rolling deformation and rolling temperature on the microstructure and mechanical properties of the alloy.It was found in the study that with the increase of rolling deformation,the volume fraction of ferrite and the grain size of nanocrystals increases,but the volume fraction of nanocrystals gradually decreases.When the rolling temperature is 1000°C,the mechanical properties of the alloy increase significantly with the increase of the rolling deformation.Especially,the overall mechanical property of the deformation of 80% is best.The hardness,tensile strength,yield strength,and elongation were 365.84 HV,989 MPa,780 MPa,and 54.6%,respectively,which were 24.9%,60%,73.3%,and 118.4% higher than those of ordinary 2205 duplex stainless steel.In addition,when the same amount of deformation the size of the crystal grains increases with the increase of rolling temperature,but the mechanical properties decrease.At the same rolling deformation of 80%,the comprehensive mechanical properties of the samples at 1000 °C and 600 °C are excellent.Among them,the alloy has particularly good plasticity after rolling at 1000°C,which can reach 54.6%,and after being rolled at 600°C,the strength is high and can reach 1103 MPa.