In-depth analysis of marine anti-corrosion coating application technology status and development

Marine corrosion prevention is one of the key technologies of marine engineering, and stress corrosion fracture (SCC), hydrogen brittleness (HE), corrosion fatigue (CF), intercrystalline corrosion (IC) caused by corrosion in the ocean will cause sudden fracture of offshore steel structure, resulting in ecological disaster of marine environment, resulting in great losses. In addition, the early failure of anti-corrosion coatings in offshore products and the down-work stopping losses caused by coating repairs are also considerable. Therefore, appropriate anti-corrosion techniques must be adopted to solve the problem.in recent years, more and more attention has been paid to marine corrosion and protection, although a variety of seawater corrosion-resistant materials continue to be introduced, a variety of anti-corrosion construction technology has also been greatly developed, but still far from meeting the actual needs. China's anti-corrosion research on marine engineering structure facilities and foreign developed countries have a clear gap, some key technologies have not been resolved, did not form a technology with China's independent intellectual property rights, and lack of corresponding anti-corrosion norms and standards, which seriously affect the design, construction and safe operation of marine engineering structure. Therefore, in view of the commonality and key corrosion prevention problems faced by key sea areas and major marine projects in China, it is of great significance to carry out long-term anti-corrosion key technical research on marine engineering structural facilities, not only to prevent corrosion, avoid or reduce the maintenance, maintenance costs and economic losses caused by maintenance, but also to reduce the occurrence of major malignant accidents.。 1. Marine anti-corrosion coatings are required Marine anti-corrosion coatings refer to anti-corrosion coatings used in the marine environment. Because the marine environment is very harsh and highly corrosive, marine corrosion prevention is an urgent and urgent subject in the development of marine engineering in China.according to the anti-corrosion object material and corrosion structure, marine anti-corrosion coating can be divided into marine steel structure anti-corrosion coating and non-steel structure anti-corrosion coating. Marine steel structure anti-corrosion coating mainly refers to the transport of ships, containers, sea bridges, port machinery, pipelines, offshore oil platforms and other large-scale facilities of anti-corrosion paint, non-steel structure marine anti-corrosion paint mainly refers to marine concrete structure anti-corrosion paint. Marine anti-corrosion coatings are mainly inorganic zinc-rich, organic zinc-rich, silicone, epoxy, acrylic, polyurethane, fluorocarbon, polysilica coatings, according to different marine environmental corrosion characteristics and anti-corrosion years to choose different coatings and coating systems.marine anti-corrosion coatings generally require the following properties: (1) have good physical properties. Good impermeability to corrosive media and good adhesion to steel surface; (2) Has good performance in magic. Resistant to seawater flushing, sea ice collision, ship docking wear; (3) Excellent chemical properties. Resistance to seawater, salt spray, oil, chemicals, UV and other erosion; (4) Good compatible with electrochemical protection system. Splash zone and full immersion area coating should be cathode-resistant; (5) has good construction performance. High-quality coating construction of different structures can be carried out under various environmental conditions. (6) Meet the requirements of health, environmental protection and safety. The coating is required to have a high solid content and the volatile organic compound (VOC) content meets the requirements of national or international standards; (7) Other special requirements. Such as: freshwater cabin coating requirements non-toxic and in line with national health certification requirements; The chlorine content of the coating used on the stainless steel surface should not exceed 200 mg/kg, and the coating does not contain zinc; Ship ballast cabin coatings should meet the requirements of the International Maritime Bureau (IMO) "Ship ballast cabin protection coating performance standards"; The coating of the part below the ship's waterline requires the prevention of attachment of sea creatures, etc.are: (1) ISO12944 protective coating system corrosion protection against steel structures, the main relevant international standards for marine heavy anti-corrosion coatings used in marine areas are: (1) (2) NORSOKM501 surface treatment and protection coatings; (3) THE performance requirements of ISO20340 offshore and related structural protective coating systems; (4) the corrosion control of the offshore structure by the NACESPO108 protective coating; (5) IMO ship ballast cabin protection coating performance standard (PSPC).marine anti-corrosion coatings and their coatings are usually required to meet the requirements of ISO12944, NORSOKM501, NACESPO108 and ISO20340 related corrosion standards. Generally have to pass strict corrosion test and certification in advance, the main test projects are: (1) salt spray resistance (salt water) test 4000h; (2) cathode-resistant peeling test; (3) wet-resistant heat test 4000h; (4) Cycle corrosion test 4200h.。 2. Marine anti-corrosion coating research and development focus Marine anti-corrosion coating research and development with high scientific and technological content, long development cycle, large investment, high technical difficulties and risks, foreign marine anti-corrosion coating research and development is mainly concentrated in the strength of large companies or government-supported departments. For example, the United Kingdom IP, the United States PPG, Denmark's Hemple, Norway's Jotun and Japan's Kansi coatings and other large companies have hundreds of years of relevant paint development history, in the paint production and supply, quality supervision, coating specifications and coating site management, etc. formed a set of very strict and strict system, the current products of these companies occupy the main market of China's marine anti-corrosion coatings.China's marine anti-corrosion coating production is mainly concentrated in Qingdao, Shanghai, Dalian, Tianjin, Changzhou, Guangzhou and Xiamen and other coatings enterprises, research work mainly concentrated in the Chinese Academy of Sciences Institute of Oceanographic Research, the Institute of Metal Corrosion of the Chinese Academy of Sciences, the Institute of Marine Chemical Research, CNOOC Changzhou Paint Research Institute, China Shipping 725 and other research institutions. In recent years, although the establishment of "China's shipbuilding industry ship coating Xiamen testing station", "marine paint product quality supervision center" and other quality management supervision bodies, but the overall level of technology is still lagging behind advanced countries., the research and development of marine heavy anti-corrosion coatings abroad mainly focuses on the following aspects.2.1 Long Life Because more and more super-large steel structures and the characteristics of the sea area do not have the conditions for direct re-painting or back-to-shore construction, it is required to develop marine anti-corrosion coatings with long service life, ideally the coating service life includes the on-site direct coating repair after the extended service life is equivalent to the life of steel structure equipment, that is, the coating and equipment with the same life design, use only a small amount of repair, no heavy coating. Belgian coated galvanizing is an organic high zinc-rich coating with a 96% zinc content in the dry film, and in the coastal ocean atmosphere of Oslo, Norway, the average annual coating loss measured after coating a single zinc coating 15a thick on a steel bridge is only 1 m.The most typical success story for inorganic zinc-rich coating applications is Morganwyalla's 250km pipeline project in Australia, which uses a single-layer water-based inorganic zinc-rich coating, which remains in good condition for more than 50 years and is free of corrosion. Exxon's refinery on Sulfur Ball Island uses a single-layer zinc silicate corrosion-proof coating, which requires only a small portion of the coating to repair after 15a, and then 4a is intact and rust-free.as a paint, the current development of fluorocarbon coatings and polysilica paint weather resistance has reached more than 15a, such as Japan's Asahi Nitro subsidiary production of Teflon FEVE fluorocarbon paint, Dajin company produced Teflon FEVE fluorocarbon paint, international paint company production of acrylic polysilica coating interfine979 and the United States Cameron company produced PSX700 and so on.2.2 Low surface treatment Since pre-coating costs account for 60% of the total coating cost, low surface treatment coatings have become one of the important research directions of anti-corrosion coatings.years, China's flooring industry has made remarkable progress, making outstanding contributions to economic development, improving people's livelihood, increasing employment, expanding exports and social welfare. However, in recent years, inflation, labor costs, real estate regulation and other adverse factors, so that some small and medium-sized floor enterprises are facing great pressure to survive. How can we further demonstrate the vitality and competitiveness of the floor?The spring of flooring enterprise development is over a senior person who has been running flooring enterprises for more than 10 years points out that the spring of flooring enterprise development is over, and Chinese flooring enterprises are now facing "four major bottlenecks": RMB appreciation, rising prices of bulk raw materials, accelerating labor costs, and increased management and employee-level conflicts leading to rising management costs. The development bottleneck indicates that the development crisis of flooring enterprises has come.
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