NS411

NS411 corrosion resistant alloys are mainly Hastelloy and Ni-Cu alloys, etc. As the metal Ni itself is face-centered cubic structure, the crystallographic stability makes it able to accommodate more alloying elements than Fe, such as Cr, Mo, Al, etc., so as to achieve the ability to resist various environments; at the same time, nickel itself has a certain corrosion resistance, especially the resistance to stress corrosion caused by chloride ions. In strong reductive corrosion environment, complex mixed acid environment, containing halogen ions in the solution, the nickel-based corrosion resistant alloy represented by Hastelloy has an absolute advantage over iron-based stainless steel.

NS411 metal material in corrosive media has the ability to resist the erosion of the medium, called the corrosion resistance of metals. High corrosion resistance in pure metals usually have one of the following three conditions.  (1) high thermodynamic stability of the metal. Usually can be used to judge the standard electrode potential, its value is more positive stability is higher; more negative stability is lower. Good corrosion resistance of precious metals, such as Pt, Au, Ag, Cu, etc. belong to this category. (2) easy to passivate the metal. Many metals can form a protective dense oxide film in the oxidizing medium, a phenomenon called passivation. The most easily passivated metals are Ti, Zr, Ta, Nb, Cr, Al, etc.  (3) the surface can generate insoluble and protective corrosion products film of the metal. This situation only occurs when the metal is in a specific corrosive medium, for example, Pb and Al in H2SO4 solution, Fe in H3PO4, Mo in hydrochloric acid solution and Zn in the atmosphere, etc.