AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Does aluminium corrode in water12/19/2023 ![]() ![]() ![]() Without proper precautions and finishes, corrosion to these components can damage the building envelope’s structural integrity, leading to systemic failure. Aluminum windows, storefronts, entrances and curtain walls, sun shades, canopies, skylights, column covers, rainscreens, and exterior panels all integrally connect to a building’s façade. Photos courtesy Super Sky Products EnterprisesĬoastal areas are beautiful locations for commercial and residential buildings, but also pose the greatest challenges in protecting exterior-facing architectural aluminum products from corrosion. In a submerged zone, about 10 percent of the sacrificial anodes (zinc, magnesium) necessary for protecting carbon steel, provide effective protection for aluminium.Photos ©.Permanent moisture in crevices is to be avoided.Natural cleaning of the surface by rain is advantageous.Painting used as an insulator should only be applied to the cathodic surface.Avoid galvanic contact with carbon steel.On aluminium boats, prevent additional electrical currents on the metal parts of a boat, do not ground to the boat structure, and use an isolation transformer for shore connection.Use A4-quality (316l or 1.4571) stainless steel fasteners or aluminium rivets. ![]() Another insulation alternative is to use sealing wax or caps on the bolt head, nuts and washers. This established method is also used to connect pipe flanges offshore. The insulation must break all contact between the metals. Where different metals are used in combination, galvanic corrosion can be prevented by electrically insulating them from each other.In addition to choosing the right aluminium alloy, here are some tips to ensure a long-lasting aluminium structure in marine and offshore environments: Testing the intergranular and exfoliation corrosion performance of an aluminium alloy is done by the NAMLT and ASSET tests, specified in the ASTM B928 standard for "High Magnesium Aluminum Alloy Products for Marine Service and Similar Environments." Corrosion-resistant aluminium alloys in marine and offshore However, with use of the right alloying elements and production recipe, this increased risk can be eliminated. Sensitization is a very slow process occurring even at room temperature, but significantly faster at higher temperatures (>65☌). This process occurs during the production of the material, as well as after. This is caused by the tendency of Mg atoms to precipitate as anodic β-phase (Mg5Al8) particles, on grain boundaries. However, normally with Mg exceeding 3 percent, the risk for intergranular and exfoliation types of corrosion increases. The strength of the above alloys increases with the magnesium (Mg) content. Intergranular and exfoliation corrosion performance of aluminium alloys However, aluminium alloys perform differently in saltwater environments or in a saline atmosphere. Here are the best aluminium alloys to use in marine environments.Īluminium has excellent corrosion resistance because it spontaneously forms a thin but effective oxide layer that prevents further oxidation. One of the strengths of aluminium is its inherent corrosion resistance. ![]()
0 Comments
Read More
Leave a Reply. |