TECHNOLOGY

The impact of Corrosion

The annual global cost of metal corrosion is estimated at more than $ 2 trillion (1.8 trillion euros), but experts estimate that 25 to 30 percent could be avoided with proper corrosion protection.

Poorly planned construction projects can result in the need to replace a corroded structure, which is a waste of natural resources and contradicts global concerns for sustainability.

In addition, corrosion can lead to safety issues, loss of life, additional indirect costs and damage to reputation.

The Corrosion

Corrosion occurs when a metal is naturally converted to a more stable form such as its oxide, hydroxide or sulfide state, which leads to deterioration of the material.

Metal corrodes when it reacts with another substance such as oxygen, hydrogen, electric current, or dirt and bacteria. Corrosion can also occur when metals such as steel are put under excessive stress, causing the material to tear.

The most common type of corrosion occurs when iron is exposed to atmospheric oxygen in the presence of water, creating a red iron oxide commonly known as rust.

Rust can form on steel and other iron alloys. Rusting of iron can also occur when iron reacts with chloride in an oxygen-poor environment, while other types of corrosion products can be formed directly from metallic iron or iron hydroxide.

The annual global cost of metal corrosion is estimated at more than $ 2 trillion (1.8 trillion euros), but experts estimate that 25 to 30 percent could be avoided with proper corrosion protection.

Poorly planned construction projects can result in the need to replace a corroded structure, which is a waste of natural resources and contradicts global concerns for sustainability.

In addition, corrosion can lead to safety issues, loss of life, additional indirect costs and damage to reputation.

Cold galvanizing is the application of a metallic zinc coating to iron or steel without the action of heat.

A zinc film with at least 96% active zinc of high chemical purity, polymeric binders and volatile agents (Zinker’s formula) is applied. Galvanization prevents the reaction of iron or steel with its environment thanks to a cathodic protection function. Oxidation of metals is prevented.

Uniform surface corrosion
Uniform surface corrosion is the most common form of corrosion, which generally occurs uniformly over large areas of a material’s surface.

Pitting corrosion
One of the most aggressive forms of corrosion, pitting corrosion, is often difficult to predict, identify or characterize.

This type of localized corrosion occurs when a local anodic or cathodic point forms a corrosion cell with the surrounding surface. This puncture point can create a hole or cavity that generally penetrates the material in a vertical direction from the surface down.

Pitting corrosion can be caused by damage or rupture of the oxide layer or a protective layer, and it can also be caused by irregularities in the structure of the metal.

This dangerous form of corrosion can cause structural failure despite relatively little metal loss.

Cavernous corrosion
This form of corrosion occurs in areas where access to oxygen is restricted, such as under washers or screw heads.

This localized corrosion generally results from a difference in ion concentration between two zones of metal. The stagnant microenvironment inhibits the flow of oxygen, thereby stopping repassivation and creating a stagnant solution that removes the pH balance from the neutral range.

The imbalance between the space and the rest of the material contributes to the high corrosion rates. Pitting corrosion can occur at lower temperatures than pitting corrosion, but can be minimized by proper design of connection elements.

Corrosion cracking
Stress corrosion cracking refers to the growth of cracks due to a corrosive environment that can cause ductile metals to fail when under stress, especially at high temperatures.

This type of corrosion is more common in alloys than in pure metals and is dependent on the specific chemical environment, with only low concentrations of active chemicals required for catastrophic cracking.

Intergranular corrosion
Intergranular corrosion occurs when there are impurities at the grain boundaries that form during the solidification of an alloy. It can also be caused by the buildup or depletion of an alloying element at grain boundaries.

This type of corrosion occurs along or alongside the grains and affects the mechanical properties of the metal, although most of the material is not affected.

Galvanic corrosion
This form of corrosion occurs when two different metals in physical or electrical contact are immersed in a common electrolyte (eg salt water) or when a metal is exposed to different concentrations of electrolyte. When two metals, called a galvanic pair, are immersed together in a liquid, the more active metal (the anode) corrodes faster than the more noble metal (the cathode).

The galvanic series determines which metals will corrode the fastest, which is useful when using a sacrificial anode to protect a structure from corrosion.

Zinker

The technology used by the manufacturer is based on the principle of cathodic protection which combines, through an innovative formula, a high zinc content 96%, pure at 99.995%, with a special, patented, superior quality polymer and an agent. solvent.

This innovative formula, tested and proven for more than fifteen years, provides superior protection against corrosion and guarantees strong adhesion to metal surfaces.

  • Zinker researchers were able to develop a formula whose characteristics allow application at very low temperatures;
  • Applications possible down to -30 degrees Celsius;
  • Zinker is the only one that withstands the great Canadian cold;
  • A unique feature!

protege structure

Zinker protects steels in temperatures ranging from -60°С to + 150°С (and for a short period from + 180°С to + 210°С for powder coating application).

While most coatings on the market cannot be applied below 5°C; Zinker was applied by contractors in Kazakhstan at temperatures of -30°C. This is a unique feature that will allow contractors who use Zinker to extend their service offer during the winter period, particularly in cold regions, such as Canada.

The coating bonds to the steel, thanks to the special polymer and thanks to the quality of the pure zinc used in the formula. The effect will also be the result of the good preparation of the surfaces and thanks to the resulting galvanic pair Zn-Fe.

  • Zinker is a formula whose product is elastic, resistant to vibrations, shocks and abrasion.
  • Applicable in all environments.
  • Guaranteed resistance in corrosive environments very high C4, high C5.
  • A protection period of more than 15 years in the most extreme conditions,
  • In coastal and offshore areas with a high salt load.
  • In buildings where condensation is almost constant and at high levels of air pollution.

corrosion categories

Cold galvanizing is the application of a metallic zinc coating to iron or steel without the action of heat.

A zinc film with at least 96% active zinc of high chemical purity, polymeric binders and volatile agents (Zinker’s formula) is applied. Galvanization prevents the reaction of iron or steel with its environment thanks to a cathodic protection function. Oxidation of metals is prevented.

First of all, the mixture should be used as a self-sufficient coating (otherwise, it is not about galvanizing, but about the coating system); second, it must have protective power like other galvanizing methods.

Zinc coatings, regardless of the method of application, have a protective effect only until they are able to actively dissolve under the influence of external corrosion.

If zinc loses the ability to actively dissolve, its cathodic protective effect decreases until complete disappearance! The capacity of the polymer film during the curing of certain types of binders to block the dissolution of zinc, makes it impossible to protect against corrosion in such coatings (in particular: polyurethane, epoxy, acrylic).

After application, the galvanized film forms a matt metallic gray protective layer. During weathering, weather-resistant protective layers of zinc oxide and basic zinc carbonate are formed – the protective layer turns dark gray. The protective layer corrodes due to the effects of atmospheric influences – the thickness of the galvanized film layer decreases.

The durability of the corrosion protection depends on the layer thickness of the galvanized film and the atmospheric conditions.