Cold rolled steel is steel produced by cold rolling. Cold rolling is to further thin the steel plate to a target thickness at room temperature. Compared with hot-rolled steel plates, cold-rolled steel plates have a more precise thickness, smooth and beautiful surface, and have various superior mechanical properties, especially in terms of processing performance. Because cold-rolled raw coils are relatively brittle and hard and not suitable for processing, cold-rolled steel plates usually need to undergo annealing, pickling, phosphating and surface smoothing.
The difference between cold-rolled steel and hot-rolled steel is not in the smelting process, but in the rolling temperature, or the rolling termination temperature. If the final rolling temperature is lower than the recrystallization temperature of the steel, it becomes cold rolled steel. Hot-rolled steel is easy to roll and has high rolling efficiency. However, the steel is oxidized under hot-rolling conditions and the surface of the product is dark gray and dull. Cold-rolled steel requires high-power rolling mills and low rolling efficiency. In addition, intermediate annealing is required during the rolling process to eliminate work hardening, so the cost is also high. However, cold-rolled steel has a bright surface and good quality and can be directly used for processing. Finished products, so cold rolled steel plates are widely used.
Cold-rolled plates are products obtained by cold-pressing hot-rolled sheets. Due to multiple passes of cold rolling, its surface quality is better than that of hot-rolled sheets. After heat treatment, it can obtain good mechanical properties.
Summary: In terms of anti-corrosion performance under the same conditions, galvanized steel sheets have better performance than cold-rolled steel sheets. The coating of galvanized steel sheets is mainly to prevent oxidation corrosion. Cold-rolled steel plates have slightly poor corrosion resistance and will oxidize and rust when in contact with air.
Cold-rolled plates have relatively high thickness accuracy and strength. In addition, zinc alloy and stainless steel have extremely strong corrosion resistance, and their prices are far higher than galvanized plates.
The base material of galvanized steel sheets is cold-rolled sheets or hot-rolled sheets. The drawing performance of galvanized steel sheets is not as reliable as cold-rolled sheets. Galvanized steel sheets are not as easy to weld as cold-rolled steel sheets, and the zinc layer is damaged during welding.
Cold-rolled steel plates and galvanized steel each have their own advantages and disadvantages, and the price difference is within a thousand yuan per ton (there are many models that I will not list here), and the surface is spray-painted and the effect is not as great as imagined. Galvanized steel sheets are as prone to rusting as the surface paint peels off after being used for a period of time. This is not as magical as some manufacturers boast. It mainly uses features that the user unit does not understand to raise its price.
