What is the difference between hot-rolled galvanized sheet and cold-rolled galvanized sheet?
2020年3月12日
- Get In Touch: +86-18115459757
common coating defects
In the conventional trading of galvanized sheet, cold-rolled basic galvanizing is the main part, while hot-rolled base plate is relatively rare, so what is the
difference between hot-rolled base plate and cold-rolled base plate galvanizing products? Let’s make a simple interpretation from the following aspects:
A. cost
Because there is less one process than cold-rolled plate, the production cost of hot-rolled plate galvanizing is lower, mainly including annealing cost and cold-rolled rolling cost, and other processes of these two kinds galvanized steel are similar.
B. Quality performance
Because the hot-rolled substrate is only cleaned by pickling and annealing, its surface is relatively rough, the zinc layer has good adhesion, and the coating thickness is inclined to 140 / 140g / m2. But the thickness is not as high as that of cold rolling. Because most of them are thick zinc layer, the thickness control of zinc layer is not even. There is little difference in mechanical properties, even some properties are better than cold rolling.
C. Application field
Hot rolled galvanized sheet is not as good as cold-rolled galvanized sheet because of its size accuracy and surface quality, and its thickness is thicker than that of cold-rolled galvanized sheet, so it is often used in structural members with low surface requirements but high strength and thickness requirements. For example, the structure of washing machine, refrigerator and other household appliances, the internal structure of the car, the chassis structure of the car, the car body, roof, highway guardrail, cold-formed steel and so on. Because the cost of hot-rolled galvanized sheet is low, and with the progress of technology, the specification and thickness are becoming larger and larger, and the usage is also gradually increasing.
D. grade
The common brands of hot-rolled galvanized sheet are dd51d + Z, hd340lad + Z, hr340la, hr420la, hr550la, etc; Dc51d + Z, hc340lad + Z, hc340la, hc420la, hc550la, etc. are corresponding to cold-rolled galvanized sheet; There is also a brand that does not specify whether it is cold-rolled or hot-rolled base plate, such as dx51d + Z, which can be generally considered as hot-rolled galvanized plate.
