Study On Corrosion Behavior Of Sintered Stainless Steel Fiber Porous Material

Sintered metal fiber porous material (metal fiber felt) is a new functional material of high quality and efficient, which developed by advanced industrial countries in the last 20 years. In recent years, it has been widely used in metallurgy, petrochemistry, automotive, filtration, aerospace and defense electronic countermeasures and other fields. In practical industrial applications, metal fiber felt often used in high-temperature oxidation or sulfide atmosphere, strong acid solutions and other harsh environment, therefore,its corrosion resistance is very important. But now the study for corrosion is rarely reported, and no unitize, standardized methods, standards to evaluate the corrosion behavior of metallic fiber mat.In this paper, sintered 316L stainless steel fiber porous material has been used as the research object, sulfuric acid and hydrochloric acid as corrosive medium, through the immersion test, Potentiodynamic polarization, metallographic analysis and SEM research methods, the corrosion type, corrosion mechanism and corrosion behavior develop process of sintered stainless steel fiber porous material were explored. At the same time, the impact of corrosion media concentration, fiber-diameter, fiber felt porosity on corrosion behavior were discussed. The results showed that:(1) The main corrosion type of sintered stainless steel fiber porous material in acid aqueous solutions is internal intergranular corrosion and surface electrochemical pitting corrosion; the main reason of corrosion failure for thin diameter stainless steel fiber felt is intergranular corrosion to result in fiber rod fracture; the main corrosion type of thick fiber is surface pitting corrosion, serious pitting corrosion can lead to material failure. (2) Corrosion resistance of sintered joint among the fibers is better than that of the fiber rod.(3) With the increases of Sulfuric acid concentration, the corrosion degree of fiber felt present as a parabola;(4) The thicker the fiber diameter is, the greater the weight loss; the finer the fiber diameter is, the smaller the weight loss, and the easier the failure of materials. It is due to different types of corrosion with different diameter fibers.(5) As the porosity increases, the corrosion weight loss of fiber felt increased, and corrosion degree more severe;(6) Weight loss and Potentiodynamic polarization method for the study of high porosity sintered metal fiber porous materials corrosion behavior is effective and feasible. But in during the corrosion research, observe of surface morphology for materials, microstructure analysis and other methods should also be combined with, in order to obtain correct conclusion.The conclusion in this paper has important reference value for industrial applications of the sintered metal fiber porous material.