Let’s talk about the alloying of metals
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By adding alloying elements to the base metal that promote passivation, a material with excellent corrosion resistance is obtained once the addition amount reaches a certain proportion. If more than 12% chromium is added to iron, it is called stainless steel ； Adding nickel to chromium steel can expand the passivation range as well as improve mechanical properties ； For example, adding 14% silicon to iron yields high-silicon iron with excellent acid resistance, and so on. Furthermore, adding trace amounts of cathodic noble metals with low overpotential to certain active metals can promote passivation. Materials such as stainless steel and titanium are active in sulfuric acid at certain concentrations and temperatures; by adding 0.1–0.15% palladium or platinum to the base metal, numerous microcathodes are formed on the surface of the alloy, which facilitates the operation of local corrosion cells. As a result, the cathodic current increases rapidly, reaching the passivation region quickly and thereby enhancing the corrosion resistance of the metal.
The alloying of metals is achieved by adding specific alloying elements to the base metal in order to improve its properties, particularly corrosion resistance. For example, adding more than 12% chromium to iron to form stainless steel significantly improves its corrosion resistance. Furthermore, adding nickel to chromium steel can expand the passivation range and improve mechanical properties. Furthermore, adding 14% silicon to iron yields high-silicon iron, which possesses excellent acid resistance. In certain active metals, the addition of trace amounts of cathodic noble metals with low overpotential (such as palladium or platinum) can also promote passivation. These precious metals form microcathodes on the alloy surface, enhancing the operation of local corrosion cells and rapidly increasing the cathodic current, thereby improving the corrosion resistance of the metal. .