Today, we will talk about how to choose color-coated steel plates for construction.

In recent years, color-coated steel plate has become one of the most scientific and technological and market vitality of steel varieties in China. As the raw material of prefabricated construction products, because of its rich color, beautiful novel and flexible combination of decoration, as well as the advantages of a lightweight, high strength, waterproof and seismic performance, compared with traditional brick and concrete enclosure structure, it has the characteristics of long life, saving land, recyclable and so on. It is widely used in the enclosure structure system of public buildings and industrial factories.

The requirements for the materials of the building (roof board and external wallboard) include safety performance (impact, wind pressure and fire resistance), residential performance (waterproof, heat insulation and sound insulation), durability (pollution resistance, weather resistance), production processability (economy, processability, maintenance).

For the ultimate owner of a building, safety and service life are the most important. In the design unit, service life, carrying capacity, shape and so on are more important.

The machinability of color steel plates (surface hardness, wear resistance, steel plate strength) is the first choice for building wall and roof processing enterprises.

Of course, the quality of the color-coated steel plate mainly depends on the color-coated steel plate manufacturer, but the wrong processing and installation equipment and methods will damage the appearance and life of the final product.

The performance indexes of color-coated steel plates include：

Substrate: yield strength, tensile strength, elongation.

Coating: coating weight, adhesion.

Coating: color difference, gloss, T-bending, impact, hardness, quality, etc.

Surface: Surface flaws visible to the naked eye and so on.

Shape: tolerance, roughness, etc.

01

Steel grade

The bearing weight of the building (wind load, snow load, construction company machinery), the span of the building, the design of the purlin are all based on the strength of the steel plate, there are corresponding standards for coloring and aluminized galvanized steel plates for building maintenance structures at home and abroad.

Such as: Chinese GB/t 1274-2006, American ASTM653, ASTM792, Japanese JISG3302, JISG3321, European EN10215, EN10147, etc.

According to the type of steel, it is divided into CQ, DQ, HSS and FH.

CQ: The DX51D grade manufactured by Shinmade has a yield strength between 260-320MPa, and the tensile strength between 350-400 MPa uses a slightly higher yield rate than structural steel.

DQ: Generally, color-coated panels for construction are roll forming or composite sandwich cores, which do not require high stamping performance of materials. Therefore, DQ grades are mainly used indoors, in windows, pipes and other industries.

HSS: High-strength structural steel: According to the European standard HSS, it can be divided into 4-5 kinds of strength steel, but CQ grade materials can already replace low-strength HSS steel, so the yield strength is more than 280MPa and 345MPa. Two kinds of steel, S280GD and S350GD. Compared with CQ, HSS steel has some major advantages.

1) Due to the small deflection, the steel has good fire resistance and shock resistance.

2) In the case of thick steel plates, long-distance arch slabs can be produced.

3) For typical exterior wall and roof panel types, it is much thinner than CQ material, thereby reducing material consumption.

FH: All hardened steels: A steel that increases the yield strength of steel plates by controlling the annealing temperature. According to international general standards, the yield strength is 550MPa and the tensile strength is 570MPa. This material has high strength and low elongation and is suitable for plate shallow formed steel plates, which greatly saves the use of materials.

Select plating coating

02

Select plating painting and coating

The plating coating is designed to ensure the durability and corrosion resistance of the building. For other purposes, another plating, coating and thickness can be selected to meet its life.

Coating

At present, the commonly used coatings of architectural color coatings are hot-dip galvanizing, aluminum-zinc plating, and aluminum-zinc-magnesium plating. In painting, there is not much difference in the application fields of various substrates. In a relatively acidic environment, aluminum-zinc-plated substrates are better. The aluminum-zinc-magnesium coating has super anti-corrosion performance. In most cases, its performance is better than that of the aluminum-zinc steel plate with the same coating amount, and it is also better than the galvanized steel plate.

For the thickness of the coating, the general requirements for the roof and sheath are hot-dip galvanizing 180g/m², galvanized 100-200g/m², and the coating weight range of galvanized zinc-magnesium is 100g/m²～180g/m². The common coating weight is 150g/m².

Painting

Must meet the user's requirements for color and durability, for the processing industry, but also meet the processing performance.

Therefore, the type of painting, color and gloss, and painting thickness must be stated when ordering. Currently commonly used topcoat varieties of coil coatings include PE, PU, SMP, PVDF and HDP.

The choice of color mainly considers the matching with the surrounding environment and the owner's hobbies, but in the use of technology, bright colors have strong heat reflection, if they are cleaned and maintained well, their lifespan will be prolonged and they will be more beautiful.

The loss of gloss is the first phenomenon that occurs in the outdoor use of color-coated steel plates. In particular, the initial matte speed of high-gloss products is relatively too fast, so color steel plates for outdoor construction are generally low-gloss.

In addition, use products made by applying the same paint on the same building. Color-coated steel plates of different brands or different batches of color-coated steel plates of the same brand will have different coating powdering speeds after being used outdoors for a certain number of years. Therefore, the effect of different colors for a certain period of time will appear during the construction process, which may harm the appearance.

On the microscopic level, the coating is a porous structure, water in the air, and corrosive media (chloride ions, etc.) invade through the weak part of the coating, causing corrosion under the film, and peeling off when the coating is blistered. In addition, even with the same coating thickness, the second coating is tighter than the first coating.

The color-coated plates used in construction are mainly affected by ultraviolet rays in the sun, moisture in the air and harmful substances caused by industrial pollution to reduce the service life. The anti-corrosion of color-coated products for construction is the combined effect of coating, pre-treatment film and coating (primer, topcoat and back paint). This combination is very important and directly affects its service life.

The above is the color-coated knowledge we shared today. The Shinmade digital high-performance corrosion-resistant new material project is tentatively scheduled to be put into production in March next year. At that time, Shinmade will provide you with different specifications, coatings, and coatings according to your needs, fully meeting your product requirements.