| With the rapid development of China's economy and the increasing living standards of people,people's demand for health is also stronger.In order to meet people's requirements,the Institute of Metal Research of the Chinese Academy of Sciences has developed an antibacterial type of stainless steel.The killing rate of Escherichia coli,Staphylococcus aureus and common bacteria in the environment reaches 90%.In order to make it widely applicable to all aspects of people's daily life,research on its weldability is particularly important.Tungsten argon arc welding has many advantages such as beautiful weld bead formation,stable arc,and effective air isolation during welding.In this paper,antibacterial stainless steel is welded by tungsten argon arc welding to study the welding process,mechanical properties,corrosion resistance and antibacterial properties of joints.In this paper,the diameter of the tungsten electrode is 1.6mm,the flow rate of argon gas is 8L/min,and the thickness of 1mm thick 304 Cu antibacterial stainless steel is welded without filling the welding wire.By adjusting the welding speed and the welding current,the range of weldability of the antibacterial stainless steel was explored,and then the design of the two factors and five levels of orthogonal test was used to find the primary and secondary of the two factors and the optimal level of each factor.Determine the optimum welding parameters for antimicrobial stainless steel.The antibacterial stainless steel welds obtained using the best parameters were compared and verified by a tensile test on the welds of 304 stainless steel.The weld microstructure and hardness of the antibacterial stainless steel were analyzed by optical microscope and hardness tester.The corrosion resistance and antibacterial properties of the weld were compared by electrochemical corrosion test and antibacterial test.The test results show that if the welding speed is less than 30cm/min or more than 63cm/min,if the welding current is less than 75 A or greater than 95 A,there will be no penetration or burn through.According to the range analysis method of orthogonal test,the five levels of welding speed are scattered,which has a great influence on the mechanical properties of the joint,and the welding current is second;the optimum welding process parameters are: welding speed 52.1cm/min,Welding current 93 A.For the metallographic analysis of the weld,it can be seen that the grain direction of the middle part of the antibacterial stainless steel weld is generally parallel.The weld structure is mainly coarse equiaxed columnar austenite,and ferrite distributed along the columnar crystal.Analysis of the hardness of the weld shows that the hardness of the antibacterial stainless steel weld is high,and the hardness of other areas is low.It can be seen from the antibacterial test that the antibacterial performance of the antibacterial stainless steel weld and the base metal is much higher than that of the 304 stainless steel weld and the base metal,and the antibacterial performance of the antibacterial stainless steel weld is higher than that of the base material,because the antibacterial of the material The performance is closely related to the corrosion resistance.The poorer the corrosion resistance,the more copper ions are dissolved on the surface of the material,which makes the material have excellent antibacterial properties.For the weld and base metal of antibacterial stainless steel,since the weld is essentially an as-cast structure,its corrosion resistance is worse than that of the base metal,and thus more Cu ions are dissolved in contact with the solution,which makes it better.Antibacterial properties.The results of electrochemical corrosion test show that the corrosion resistance of the four samples is as follows: 304 stainless steel base metal,304 stainless steel weld,antibacterial stainless steel base material,antibacterial stainless steel weld,indicating that the antibacterial stainless steel is added with copper.Corrosion performance has been reduced. |
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