Effect Of Deep Cryogenic Treatment On Corrosion Properties And Wear Resistance Of 316L And 2205 Stainless Steels

With the continuous development of science and technology,the scientific exploration and development of marine resources is now progressing at a great speed.In this process,we often use a variety of marine materials and marine equipment.The seawater environment is complex and changeable.The corrosion and wear of materials in the seawater environment have been the key issues affecting the development and research of marine resources.Cryogenic treatment is often used to improve the strength,toughness and wear resistance of materials by improving the internal structure and composition of materials.On this basis,the corrosion resistance and wear resistance of 316 L austenitic stainless steel and 2205 duplex stainless steel commonly used in marine industry after cryogenic treatment were studied.The results show :(1)After cryogenic treatment,amount of martensite was formed in 316 L austenitic stainless steel.The microhardness of the original material and welding material increased by about 12%.The tensile strength and yield strength increased by 6% and 10%.For 2205 duplex stainless steel raw material,cryogenic treatment has little effect on its properties.The microhardness of welding material is increased by 19%,while the tensile strength is increased by 12%,and the yield strength is increased by 10%.(2)After cryogenic treatment,the modulus of electrochemical impedance spectroscopy(EIS)of 316 L austenitic stainless steel decreases,and the polarization curves show that the self-corrosion potential moves in a negative direction and the self-corrosion current density increases,indicating that cryogenic treatment reduces the electrochemical properties of 316 L austenitic stainless steel.The modulus,impedance,self-corrosion potential and self-corrosion current density of 2205 duplex stainless steel original material did not change significantly.Smooth and smooth surface was observed in the corrosion morphology,indicating that cryogenic treatment had no effect on the electrochemical properties of 2205 duplex stainless steel original material.The mode value and impedance value of 2205 duplex stainless steel welding material are obviously improved,the self-corrosion potential moves to the positive direction,and the self-corrosion current density decreases.At the same time,the corrosion morphology of the material is observed and there are obvious corrosion pits on the surface of the material without cryogenic treatment,which indicates that cryogenic treatment improves the electrochemical corrosion performance of 2205 duplex stainless steel welding material.(3)After cryogenic treatment,the wear resistance of 316 L austenitic stainless steel was improved and the friction coefficient decreased by about 25% due to the transformation of retained austenite to martensite.The wear properties of 2205 duplex stainless steel are not affected much,the wear properties of welding materials are improved,and the friction coefficient is reduced by about 20%.