Study On Corrosion Resistance Of 316L Austenitic Stainless Steel By Increasing Nitrogen Element And Decreasing Nickel Element

Austenitic stainless steel is used in many fields such as medical and health,chemical reaction vessels,military projects,etc.due to its good overall performance,and about 70%of the total stainless steel output is austenitic stainless steel.Among them,low-nickel or nickel-saving austenitic stainless steel has good development prospects due to price reasons.Past research results have shown that the N element in austenitic stainless steel can play a role in precipitation hardening,stabilizing the austenite zone,and refining grains.Therefore,by controlling the content of N and Ni elements in austenitic stainless steel,the price of austenitic stainless steel products is reduced,adverse reactions to human organs are reduced,and the corrosion resistance of steel grades is improved.In this experiment,316 L stainless steel was used as the basic steel type,and the anti-corrosion performance under different N-Ni element contents was studied by means of increasing nitrogen and reducing nickel.Specifically,through the use of solution treatment,hardness testing,impact testing,tensile testing,orthogonal analysis,intergranular corrosion experiments,electrochemical experiments,transmission and other analysis to study the changes in the corrosion resistance of the four groups of experimental steel.The structure of the four groups of experimental steel samples after the tensile test was analyzed for intergranular corrosion and transmission,and it was concluded that the width of the grain boundary of the tensile sample was wider than that of the unstretched sample 1.5 times,and stretching reduces the intergranular corrosion resistance of steel.This finding is of great significance for the study of the intergranular corrosion resistance of 316 L austenitic stainless steel.Through the solution treatment,orthogonal analysis and intergranular corrosion of the four groups of experimental steel samples under different conditions,the experiment concluded that the intergranular corrosion resistance of 1# experimental steel under the condition of solid solution condition of 1100 ?-1 h The best reason is that under the solution condition of 1100 ?-1 h,the austenite grains of the sample are the most uniform,and there are also a large number of lath twins,which increases the mechanical propertiesof the structure.,Also reduces the segregation and precipitation of inclusions.A large number of twins are produced in the austenite structure.The presence of twins reduces the percentage of high-energy grain boundary energy,destroys the continuity of the original high-energy high-angle grain boundary,improves the energy required for intergranular corrosion and improves the crystal World corrosion resistance.Through transmission analysis,it is found that N element will cause a large number of dislocations in austenitic stainless steel.This phenomenon is of great significance for the strength improvement of austenitic stainless steel.In the mechanical experiment,four groups of experimental steels found that the mechanical properties and corrosion resistance of the 1# experimental steel are the best in regulating the N-Ni element,so the service environment of the steel grade should be considered in actual production applications.