The Corrosion-resistant Properties Of Molybdenum

◼ The corrosion-resistant properties of molybdenum are difficult to replace. In terms of metal properties, molybdenum's application is mainly based on its corrosion resistance. Common metal corrosion-resistant materials include stainless steel, nickel-based alloys and reactive metals. ◼ Molybdenum improves the pitting resistance of stainless steel and nickel-based alloys. Common stainless steel usually contains at least 10.5% chromium, increase chromium content can provide a thicker passivation film to prevent surface corrosion, but pitting corrosion is difficult to prevent, according to the relevant research, in order to ensure the mechanical and physical properties of stainless steel under the premise of the addition of an appropriate amount of molybdenum can improve the resistance to pitting corrosion, such as 316L, bi-directional stainless steel, austenitic stainless steel and so on. Nickel-based alloys have better overall corrosion resistance than stainless steel and usually contain about 3.0% molybdenum for the same reasons as austenitic, duplex and super duplex stainless steels, which can enhance pitting resistance. ◼ Reactive metals are either expensive or relatively limited in specific environments. Active metals are mainly titanium, zirconium, tantalum, etc. Titanium is mainly through the formation of a dense oxide film to provide protection, in the reducing or high confinement (lack of oxygen) environment is prone to corrosion, and titanium application temperature smart to 300 ℃, zirconium, tantalum corrosion resistance is strong, but the price is expensive, and most of the active metals can not be used in fluorine-containing environments, the use of the relatively limited.