When it comes to metal surfaces, protecting them from corrosion and rust is crucial. This involves the application of various methods to create a protective layer, isolating the metal from corrosive environments or minimizing contact with corrosive substances to prevent or reduce corrosion. Let's delve into the reasons behind bolt rust and corrosion and explore effective measures to prevent them.
Why Do Bolts Corrode and Rust?
Environmental Factors: Bolts are prone to corrosion in humid environments or polluted air containing sulfides, carbon oxides, and nitrogen oxides.
Chemical Exposure: Bolts can corrode when exposed to acids, alkalis, salts, or organic substances. Organic juices, in the presence of water and oxygen, can form organic acids that gradually corrode the metal surface.
Electrochemical Corrosion: Dust or metal particles with other elements can accumulate on the surface of bolts. In humid air, these particles, combined with condensed water, create a micro-battery, triggering electrochemical reactions that compromise the protective film.
Hazards of Bolt Corrosion:
Impaired Appearance: Rust can tarnish the appearance of bolts, making them visually unappealing.
Safety Risks: Rust and corrosion weaken bolts, increasing the chances of breakage and loosening. This poses significant safety hazards that can compromise property and personal safety.
Prevention Methods for Rust and Corrosion in Bolts:
To prevent rust and corrosion, it is essential to apply a protective layer on the metal surface that meets specific requirements. Before implementing preventive measures, clean the bolts thoroughly to remove any rust and dust impurities. The protective layer should have the following characteristics:
Corrosion Resistance, Wear Resistance, and High Hardness.
Compact Structure with Small Pores.
Strong Adhesion to the Base Metal.
Even Distribution and Adequate Thickness.
Here are some commonly employed methods for surface treatment to prevent rust and corrosion in bolts:
Plated Bolts: This method involves immersing the fasteners in a metal solution and applying an electric current to deposit a layer of metal on the surface. The choice of metal coating depends on specific needs, with galvanization being effective for rust prevention.
Mechanically Plated Bolts: In this process, metal particles are cold-welded to the fasteners, protecting their surface features. Mechanically plated bolts are similar to electroplated ones, as both employ different surface treatments to achieve similar results.
Chemical Heat Treatment: Chemical heat treatment is a widely used cost-effective technique to enhance wear resistance and anti-corrosion properties. It involves placing the steel in an active medium containing desired elements, heating, and maintaining the temperature to enable the penetration and alteration of the chemical composition of the surface layer.
Surface Passivation: Passivation dissolves contaminants hidden on bolts, forming a protective film that safeguards against corrosion. This method is commonly used in the surface treatment of electronic products.
Addressing Rust and Corrosion:
For mild rust, start by polishing the affected area and applying rust paint to inhibit further corrosion.
In cases of severe corrosion, it is advisable to replace the affected bolts to ensure optimal safety and performance.
By implementing appropriate surface treatments and taking prompt action against rust and corrosion, bolts can maintain their integrity and durability, preventing safety hazards and preserving their appearance.