What's the difference of cold rolled and hot rolled aluminum sheet?

- Apr 23, 2018-

In the aluminum sheet industry, there are many types of aluminum sheets, and aluminum sheets can be classified into cold-rolled aluminum sheets and hot-rolled aluminum sheets, depending on the production process.


The difference between cold-rolled aluminum sheet and hot-rolled aluminum sheet mainly lies in the difference in production process: cold-rolling is processed by a casting machine into a cast coil and processed by a cold-rolling mill; and hot-rolling is performed by heating the aluminum ingot and melting at a high temperature. And cast into a flat ingot, after milling, uniform annealing after hot rolling mill. Secondly, the raw material supply is different: the difference between the two is in the billet supply. The hot-rolled billet is cast aluminum ingots—heated—rolled into coils for rolling, and the cold-rolled billet is cast-rolled—cold-rolled. Moreover, because of different production processes, the cold rolled aluminum sheet and the hot rolled aluminum sheet have different performances: the surface quality of the hot rolled aluminum sheet is good, and the mechanical properties and ductility are strong, and the oxidation effect is good.


The cold-rolled aluminum sheet is made of hot-rolled aluminum sheet at room temperature, and is cold-rolled by hot rolling after continuous cold deformation. The mechanical properties are relatively poor, and the hardness is too high. Therefore, the cold-rolled aluminum sheet is mostly used for molds and hot-rolled. Aluminum deep-drawing, bending performance, etc. are better, so it is suitable for deep processing.

How to distinguish between cold rolled aluminum and hot rolled aluminum? 

First, by visual observation, it is generally judged that the surface of the hot-rolled aluminum plate is usually brighter; 

Secondly, the elongation rate can be tested; usually, the elongation rate of the hot-rolled aluminum plate is higher than that of the cold-rolled aluminum plate; the difference can be seen through the crystal grain. Hot rolling is a processed structure with more than 90% of thermal deformation, and simultaneous recrystallization occurs in the hot rolling process, so the grain of the strip is fine and the properties are uniform, while the middle layer of the cold strip is in the shape of a feather columnar crystal. Casting organization.