In recent years, through the investigation and analysis of aluminum production enterprises, testing institutions, authoritative experts of research institutes, etc., it is concluded that the causes of abnormal corrosion are as follows:

1. Sea sand

Sea sand or untreated sea sand shall be used as mortar during construction. The content of chloride ion in sea sand exceeds the standard. In the rainy or humid weather back to the south, the aluminum alloy doors and windows react with sodium ion and chloride ion in cement sand under the condition of water as the medium, causing corrosion.

2, cement

During construction, glue cement mixture is poured into the pipe cavity to strengthen the support strength of the pipe profile. Due to the limitation of coating process, the inner surface of the profile is usually uncoated, so if the inner substrate of the pipe directly contacts with the cement, it is easy to produce corrosion and cause perforation on the outer surface.

3. There is no anti-corrosion treatment during the installation of anti-corrosion protection: the bottom of the profile is not coated with asphalt; at the same time, the product is not wrapped with a protective film for protection, which causes scratches and scratches during the construction and transportation, resulting in the loss of the protective effect of the coating.

4. When installing aluminum alloy doors and windows with iron nails, the untreated fixed iron nails are driven in. Because the iron nails are not insulated with aluminum alloy, micro current circuit is formed in some parts, and chemical reaction occurs in rain water, especially under the action of sodium ion and chloride ion, resulting in local corrosion.

In order to prevent the occurrence of the above situations, yonglijian aluminum industry warmly reminds you that you need to take the following measures:

1) it is forbidden to use sea sand or untreated qualified sea sand as mortar.

2) it is forbidden to pour strong alkaline cement into the tube cavity.

3) a layer of anti-corrosion asphalt shall be painted on the aluminum alloy products in contact with the wall. Before the installation of the outer frame of the window, it is necessary to wrap the protective film to avoid the scratch caused by the collision of the corners during the construction and transportation. After the installation on the wall, it is forbidden to step on it directly. When the scaffold needs to be placed, it is necessary to protect the door and window frame with wood plates. During the construction of the aluminum alloy door and window, waterproof and moisture-proof measures shall be taken The gap between window frame and wall opening shall be treated with moisture-proof and anti-corrosion materials such as polyurethane pH foaming joint filler.

4) when installing aluminum alloy doors and windows, it is forbidden to use untreated and inferior nails.