| Currently, the austenitic stainless steel is the largest output, the amount of the largest and most widely used of a chrome - nickel stainless steel, widely used in all aspects of life and production.Due to the special nature of stainless steel, the corrosion resistance are important to its performance. Selected three famous domestic steel production of stainless steel plate (hot rolled 304-A and 304-B and solution heat treatment of stainless steel 304-C), combined with its microstructure, by general corrosion, localized corrosion (intergranular corrosion and pitting), Electrochemical corrosion, corrosion and salt spray corrosion creams systematic and comprehensive analysis of the hot rolled and solution heat treatment of stainless steel plates in different conditions, different media and different corrosion resistance test methods. To further enhance the quality of austenitic stainless steel products and improving process parameters provide a theoretical basis ,also provide experimental data for the development of austenitic stainless steel and guide the production.Combined corrosion curves by dipping in 11 kinds of solution at three temperatures with electrochemical corrosion of the curve can be obtained in sulfuric acid, hydrochloric acid, ferric chloride and mixed acid medium, the corrosion resistance better than 304-B 304-A and 304-C, in sodium hydroxide solution three kinds of stainless steel have similar corrosion resistance. Immersion corrosion and electrochemical corrosion test results corresponding and complement to each other.Secondly combined local corrosion immersion tests with local electrochemical corrosion test and found that 304-C resistance to intergranular corrosion than 304-A and 304-B, which is due to 304-A ,304-B,304-C grain size is roughly Equivalent, but more band within the 304-A (δ-ferrite and fine M23C6) and 304-A with higher number of WCr, Wc, part of the band is stretched across the entire field, and the band in 304-B ,304-C (especiallyδferrite) is not obvious, some of the organizations seemed more uniform. Therefore, 304-A intergranular corrosion resistance inferior to 304-C ,304-B. 304-C for the cold-rolled plate, after solution treatment, carbide and other small, homogeneous, so,304-C resistance to intergranular corrosion better. Three stainless steel pitting study found that the band in the 304-B,304-C (especiallyδferrite) compared with 304-A is not obvious, the organization appears more uniform, but the the Ep value of 304-A is higher , pitting local than 304-C is not easy nucleation occurs, and the Eb-Ep value of 304-A the is also small, and its ability to repair the passive film is better than 304-C, according to the parameters of the electrochemical pitting corrosion comparison, analysis, and connect immersion test results of 6% FeCl3, that the three steel similar pitting resistance, and has a large Eb-Ep value (0.24 ~ 0.4), has a greater tendency to pitting.Thenω(NaCl) = 1%, 3.5% and 8% of the solution as corrosive medium, temperature of the solution are: 30,50 and 80℃.Measure the polarization curves and cyclic voltammetry, combined with the number of pits and the size, we draw conclusions with increasing temperature and increasing concentration of Cl-, 304 stainless steel pits change the pore size and quantity large, larger current density, breakdown potential Eb negative shift, narrow passive region, the passive film increased the severity of damage, repair capacity of the passive film and thus the worse, and then makes the pitting susceptibility of stainless steel 304 increased.Finally, through research stainless steel composition, microstructure and processing on the corrosion of the state to study the contribution of the three factors on the corrosion resistance and found little difference in the case of stainless steel components (as opposed to GB), microstructure and processing status is the main influencing factors, so the production process in the future, to maintain the existing stainless steel on the basis of good composition control, efforts to improve the rolling process, innovation, rolling method, is the key to improve the corrosion resistance of 304 stainless steel.
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