koroziju

Koroziju, or corrosion, is the deterioration of materials due to chemical or electrochemical reactions with their environment. It most commonly affects metals, which can lose strength and integrity as they interact with water, oxygen, salts, acids, or other aggressive substances. While corrosion can occur in various materials, the metal durability problem is its most widespread and economically significant form.

Corrosion arises from electrochemical processes that require an anode, a cathode, and an electrolyte. In metals, reactions often involve oxidation of metal atoms at the anode and reduction reactions at the cathode, driven by environmental conditions such as humidity, temperature, and the presence of aggressive ions. Uniform corrosion progresses evenly over surfaces, whereas localized forms include pitting, crevice corrosion, and galvanic corrosion when different metals contact each other. Other forms include intergranular corrosion along grain boundaries and stress corrosion cracking, where tensile stresses promote crack growth.

Assessment and prevention are central to managing corrosion. Rates are commonly expressed in millimeters per year and can be estimated by weight loss measurements or electrochemical methods like polarization resistance and impedance spectroscopy. Prevention strategies include selecting corrosion-resistant materials, applying protective coatings, performing passivation to enhance protective oxide layers, and using cathodic protection or corrosion inhibitors. Proper design and maintenance—avoiding crevices, minimizing moisture retention, and controlling environmental factors—also play key roles.

Koroziju affects infrastructure, maritime operations, pipelines, automotive components, and industrial facilities, leading to safety concerns and substantial costs. Understanding its mechanisms and implementing preventive measures are essential for extending the lifespan of engineered systems.