The practical use of duplex stainless steel has a history of more than 20 years, especially contemporary duplex stainless steel with ultra low carbon nitrogen content has overcome some of the welding problems, combined with the advantages of duplex stainless steel with local corrosion resistance and good integral mechanical properties. It has created the conditions for the large-scale promotion and application of welded structural materials. Over the past 10 years, sales in the market have increased rapidly. In addition, with the introduction of super duplex stainless steel on the market, the application in some hard media has expanded, making duplex stainless steel The scope of the application continues to expand and has accumulated a lot of practical experience, which has further created the conditions for the selection of duplex stainless steel and the development of new steel grades. Duplex stainless steel has both the common characteristics of general stainless steel and its own characteristic laws. Therefore, in the double In the reasonable selection of the stainless steel phase, in addition to the various factors to be considered in the selection of general stainless steel, it is also necessary to consider the characteristics of duplex stainless steel.
When selecting duplex stainless steel in different corrosive environments, it should be noted that the corrosion resistance of the steel is always relative. Although duplex stainless steel has better resistance to local corrosion, as far as certain duplex stainless steel is concerned, it also has a range of applicable media conditions, including temperature, pressure, media concentration, pH value, etc. Many of the data obtained from the literature and manuals are the result of laboratory corrosion tests, which are often different from the actual project conditions. Therefore, you should pay attention to the selection of materials. If necessary, you should perform corrosion tests on real media or under on-site conditions Coupling test or even simulation device test.
