Preparation Of 2205 Duplex Stainless Steel Wire And Its Microstructure And Properties

2205 duplex stainless steel wire combines the excellent toughness and weldability of austenitic stainless steel wire with the higher strength and chloride stress corrosion resistance of ferritic stainless steel wire,making it have the advantages of both.2205 Duplex stainless steel wire undergoes severe plastic deformation during preparation,and the mechanism analysis of microstructure evolution process during plastic deformation is often based on morphology observation,resulting in relatively insufficient understanding of micro structure evolution behavior and mechanism.At the same time,there is a lack of in-depth study of duplex stainless steel filaments.To this end,this topic selects 2205 duplex stainless steel with wide application,and draws to obtain steel wire materials with different deformation.The deformation mechanism of duplex stainless steel wire is deeply studied.It is helpful to the optimized design of phase steel wire and even a new generation of high-strength steel wire.In this paper,the multi-pass small deformation is adopted to improve the plasticity and toughness of the duplex stainless steel wire,and the deformation amount of each pass is controlled below 20%.2205 duplex stainless steel wire with a diameter of 0.9 mm was successfully prepared under laboratory conditions.Optical microscopy,scanning electron microscopy,electron backscatter diffraction and transmission electron microscopy are used to analyze the two phases of duplex stainless steel wire under different deformations.The effects of Schmid factor and grain orientation on twins were studied,and the deformation mechanism of two phases in duplex stainless steel wires was discussed.The research results show that:(1)2205 duplex stainless steel wire was drawn in 24 passes from ?5 mm to?0.9 mm according to the experimental scheme.Through the microstructure analysis of 2205 duplex stainless steel wire under different deformation,the austenite is distributed continuously or discontinuously on the ferrite matrix.At lower deformation,the grains are slightly deformed.As the deformation increases,the grain size of the cross section gradually decreases.The longitudinal section of the grain is elongated along the drawing direction,and finally becomes a fibrous structure.Under the transmission electron microscope,it was found that when the austenite slip is not easy to occur,the twin system starts,and the ferrite continues to deform through the cross slip.In the end,dislocations are severely tangled,resulting in work hardening effect.(2)The analysis of XRD test results shows that as the amount of deformation increases,the peak of bcc gradually increases and the peak of fcc gradually decreases.From this,it can be seen that austenite to ?'-martensite phase transformation occurred during the drawing process.That is,the deformation induced martensite transformation has occurred,which greatly improves the hardness of the material.(3)The mechanical test results of 2205 duplex stainless steel wire under different deformations show that with the increase of deformation,the microhardness of the wire increases gradually.The hardness of the cross section is higher than the hardness of the longitudinal section.Yield strength and tensile strength are greatly improved,mainly because deformation-induced martensitic transformation during drawing.(4)As the amount of deformation increased,the wire texture in the austenite<001>direction gradually weakened,and a large number of stable shear textures<111>appeared in the austenite.The initial wire texture of ferrite was mainly in the<001>direction,and gradually weakened to produce a new silk texture<114>.The finely dispersed carbides precipitated during solution treatment have a promoting effect on the nucleation of<001>texture,which hinders the nucleation of unfavorable<114>and<111>texture.From the analysis of Schmid factor,it can be seen that a low Schmid factor corresponds to twins;a high Schmid factor corresponds to slip;and the middle value of Schmid factor corresponds to cross slip.It can be seen from the inverse pole diagram and the strain distribution diagram that the ferrite is the main phase affecting the plastic deformation.