In China, for the selection of color coated steel plate, the steel grade is relatively less concerned by users. Because most of the domestic color coated steel plate production There are few kinds
of steel in the plant, most of which are dc51 (because the hot-rolled plate or hard coil they purchased is basically the same steel grade). Some color coated steel plants with hot-dip galvanizing production line can produce all hard steel (S550) or high-strength
steel (S350, etc.) by hot-dip galvanizing and annealing, but it is very difficult because they can't control the quality and chemical composition of the substrate. Therefore, the quality stability is poor, resulting in large fluctuations in performance,
resulting in poor profiled sheet.
For buildings, the design of bearing capacity (wind load, snow load, construction personnel and machinery), building span, purlin distance, etc. all depend on the strength of steel plate. For color coated and aluminized
zinc plate for building maintenance structure, there are corresponding standards abroad. Such as astm653 and astm792 in the United States, jisg3302 and jisg3321 in Japan, en10215 and en10147 in Europe. It is divided into CQ (general commercial grade),
DQ (general stamping), HSS (high strength structural steel) and FH (full hard steel) according to steel types.
CQ general commercial grade nonferrous metal smelter (copper, zinc, aluminum, lead, etc.) is the most challenging color coated steel plate
service life. However, reasonable selection of materials, design, and environmental protection investment can ensure or improve the service life of color coated steel plate. 10 years of replacement or maintenance should be possible.
DQ is generally
used for stamping. Because the color plates used in general buildings are roller formed or composite sandwich, and the requirements for the stamping performance of materials are not high, it is rarely used in the construction field (except for some color
plates for doors and windows).
According to the European standard HSS can be divided into 4-5 different strength steel grades. However, the common CQ grade materials have been able to replace the low strength HSS steel. Therefore, the steel grades
with yield strength of 280mpa and 345mpa are more commonly used in the market. Tste28 and ts350gd produced by Baosteel are these two kinds of steel.
Compared with common CQ steel, HSS steel has several advantages: (1) due to its low yield strength
ratio, it has good fire resistance and seismic resistance. (2) For thick steel plate, it can be used to manufacture large span arch plate. (3) For general exterior wall and roof panel type, it can be thinner than CQ material, so as to save material consumption.