2205 duplex stainless steel is currently the most widely used duplex stainless steel in marine environments. In recent years, reports about the failure of 2205 duplex stainless steel caused by marine bacterial corrosion have attracted widespread attention from scholars. The advent of 2205-Cu, an antibacterial duplex stainless steel with extremely strong resistance to microbial corrosion, has filled the gap in my country’s field of marine antibacterial engineering materials. The research results have important academic significance and practical application value.
Since marine engineering equipment and structural parts serve in harsh corrosive environments, their underwater structures have been subject to corrosion by seawater and the action of microorganisms for a long time, which puts higher requirements on their corrosion resistance. For stainless steel used in marine engineering equipment, chloride ion corrosion and microbial corrosion in seawater have always been recognized problems around the world. Therefore, major developed countries in the world have established national strategic projects to support research and development in this field, but they have not yet achieved good results. to solve this problem. Microbial corrosion and biofouling of marine engineering materials cause economic losses of nearly one trillion yuan to the country every year; at the same time, it causes more than 30% of energy waste for navigation objects in the sea, and has become one of the technical bottlenecks that seriously restricts the development of major marine engineering technologies and equipment. First, the material failure caused by it seriously affects the reliability and life of marine engineering equipment. Therefore, the failure mechanism and protection technology of microbial corrosion of marine engineering materials have become major issues that need to be solved urgently in the field of marine engineering in my country.
Research has confirmed that the main cause of microbial corrosion of marine metal structural parts is the formation of bacterial biofilms on metal surfaces. If the bacterial biofilm adhering to the surface of metal materials can be effectively inhibited and killed, the occurrence of microbial corrosion can be effectively alleviated or inhibited. Therefore, it is an innovative new idea to utilize the antibacterial properties of antibacterial stainless steel and its inhibitory effect on bacterial biofilm formation to improve the antimicrobial corrosion ability of stainless steel. Taking advantage of the strong bactericidal properties of copper ions, a team from the Institute of Metal Research, Chinese Academy of Sciences, has successfully developed various types of copper-containing antibacterial stainless steels such as austenite, ferrite and martensite as early as the beginning of this century. These antibacterial stainless steels are beneficial to daily life. E. coli, Staphylococcus aureus, Candida albicans, Aeromonas and other bacteria that are common in life have obvious killing effects. In response to the bacterial biofilm formed on stainless steel in the marine environment, researchers have successfully developed an antibacterial duplex stainless steel (2205-Cu) that is resistant to microbial corrosion.
Research results show that the sterilization rate of 2205-Cu stainless steel reaches 96.9% after one week of co-culture with monospores that cause marine microbial corrosion under 2216E medium conditions. After two weeks of co-culture, the deepest pitting corrosion depth caused by microbial corrosion on the surface of ordinary 2205 duplex stainless steel continued to decrease. By analogy with this time interval, it was concluded that 2205-Cu antibacterial duplex stainless steel has extremely strong resistance to microbial corrosion. ability.