Steel is famous due to its strength and versatile nature and is used in industries. But to increase its use and working life, steel faces many treatments. These treatments are offered by experienced surface treatment/surface finishing professionals for increasing features like corrosion resistance, wear resistance, and durability. In this article, we will explore some of the most common steel surface treatments, including zinc coating, heat treatment, hydrophilic coating, carburizing, and surface finishing.
Why is steel surface treatment needed?
corrosion attack
- It is a general attack corrosion that causes a bad effect on the completely exposed surface of the steel. This corrosion is due to a chemical reaction that resulted the deterioration of the exposed surface of the steel. The best method to protect from this attack is to use a barrier between steel and malicious agents
Galvanic corrosion
- It occurs when steek makes a connection with another metal in a corrosive electrolyte. The best method to solve this issue is to ensure that different not make connections.
Pitting corrosion
- Pitting corrosion exists when the localized area of steel loses protection cover. This area then becomes anodic and other parts of the metal become cathodic, causing localized galvanic reaction. It can be avoided through certain diligence with steel and again using protective coating or cathodic protection.
Crevice corrosion
- It is localized, normally in a stagnant microenvironment where acidic conditions, or oxygen depletion in crevices can casues corrosion. the best method for steel protection from this type of corrosion reduces tight spaces in steel constructions.
Metal Surface Treatments for Manufacturing Processes
Electroplating
- This process makes a thin metal coating on the substrate. This process passes positive charged electrical current in a solution having dissolved metallic ions and negatively charged current through the metallic component to plated. Common metals used for electroplating are cadmium, chromium copper, gold, nickel, zinc, and tin. Base metal that conducts current can be electroplated for better performance.
Electroless Plating
- This method is like electroplating since it does not use current. The reduction agent used in place of current and performed in plating solution
Chemical Treatment
- It comes with the creation of thin films of sulfide and oxide through chemical reactions. Normal uses of metallic coloring, corrosion protection, and priming of surfaces are painted. Black oxide is a common surface treatment for steel parts and passivation is used for removing free iron from surface stainless steel parts.
Anodic Oxidation
- This treatment is used for light metals, like aluminum or titanium. These oxide films are made with electrolysis and as they are porous dyeing and coloring agetns are used for aesthetic appearance.
- Anodization is a common treatment that avoids corrosion on aluminum parts.If wear resistance is needed engineer can define type of method that creates a relatively thickness, hard, ceramic coating on the component
Hot Dipping
- It needed part dipped in dissolved tin, lead, zinc aluminum, or solder for making surface metallic film. Hot dip galvanizing is the process of dipping steel in a vessel having molten zinc. It is used for corrosion resistance in extreme conditions, guard rails of roads are processed with hot dipping
Vacuum Plating
- Vacuum vapor deposition, sputtering, and ion nitriding are common metal surface finishing processes that use high vacuum for the plating process. Ionized metals, oxides, and nitrides are made in controlled conditions. part is shifted in a vacuum chamber and metals are deposited on the substrate. Titanium nitride is a surface treatment that increases the working life of high steel and carbide metallic cutting instrument
Painting
- This treatment is commonly defined by engineers for increasing component look and corrosion resistance. Spray painting, electrostatic painting, brushing, and powder coating painting are some common methods used for applying paint to surface components. There are different types of paint formulations for protecting metal parts in larger range of physical conditions.
- The automobile industry automated the process of painting cars and trucks, using a larger number of robot arms and producing consistent results.
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