The Research on Forming Performance and Corrosion Resistance of Cold Rolled Austenitic Stainless Steel Plates
|School||Lanzhou University of Technology|
|Keywords||Austenitic stainless steel Strain-induced martensite Formability Corrosion resistance Polarization curves Pitting|
Stainless steel is widely used in the production of all aspects of life, formability, corrosion resistance is the most important performance. This article focuses on 304 austenitic stainless steel, its microstructure, focuses on the formability and corrosion resistance of cold-rolled sheet and ferritic stainless steel (430,409 L, 410S) and austenitic stainless steel (904L 316L) compared to provide a theoretical basis, in order to further improve the 304 austenitic stainless steel formability, corrosion resistance, improved process and guide the production. First studied the characteristics of 304 austenitic stainless steel strain-induced martensite, the degree of strain, stress and material state of the three important factors of 304 austenitic stainless steel strain-induced martensite. 304 austenitic stainless steel cold rolling in one-way under tensile stress, the greater the deformation-induced martensite more ,10-20% strain, the martensitic transformation is very small, 20% -40% strain , the amount of martensite transformation. 304 austenitic stainless steel hot-rolled state due to the presence of carbides and inhomogeneity, resulting in austenite is less stable than the cold rolling, the tensile strain-induced martensite more (35%), 304 stainless stainless steel cold rolling tensile strain-induced martensite less (10%). 304 austenitic stainless steel the reaming sample cup-shaped projections at the tangential and radial tensile stress can help induce the austenite to martensite transformation induced martensite (25%). Second, we study the forming properties of 304 austenitic stainless steel cold-rolled sheet, 304 stainless steel has a higher value of n, the uniform elongation δu such as forming the favorable performance of the mechanical properties, Cupping test and reaming test is a plastic forming process it is bound to be associated with some of the basic mechanics index of the material. Of course, these relationships is not necessarily a simple linear relationship between the mechanical parameters Erichsen value IE better than the hole expansion ratio lambda Delta u, sigma s / sigma b, N and lambda, IE's relationship seems better in △ r ( gamma | -) values, the grain size of the plate 304 grade, the equiaxed crystal is conducive to forming. 304 dimples for the average small dimple in the deformation in the late dimple is formed at the fine carbides, conducive to large deformation, is conducive to forming. 304 austenitic stainless steel strain-induced martensite can improve the ability of the hardening strain-induced martensite can be induced plasticity, 304 austenitic stainless steel formability than ferritic stainless steel (410S, 409L, 430 ). Finally, 304,304-20% epsilon ,304-30 ,304-40% of the epsilon epsilon, 316L, and 904L cold rolled sheet metal corrosion in oxidizing, reducing, alkaline and salt solution and cycle voltammetric determination of 304 austenitic stainless steel and variable form of pitting corrosion resistance. Measured polarization curves of stainless steel in different corrosive media, the characteristic parameters to assess its corrosion resistance. Obvious passivation platform in the corrosive medium, passive current evaluation criteria, is to determine the corrosion potential of the metal corrosion tendency. In the corrosive medium no obvious passivation passivation platform to evaluate the corrosion resistance of the corrosion current logi corrr . Oxidizing and reducing media, alkali solution, ferric chloride solution, the corrosion resistance of large to small as follows: 904L, 316L ,304,304-20% epsilon ,304-30 ,304-40% epsilon epsilon . Pitting test, the breakdown the potential Eb higher the more stable, the passivation of the metal, the higher its pitting potential desired E b and the E p < / sub> closer the value, the stronger the repair capacity of the passive film. By the the pitting morphology Photos and the E b the-E p value judgment 304 austenitic stainless steel and variable form of pitting corrosion resistance in descending order: 304 ,304-20% ε ,304-30% ε ,304-40% ε.