The carbon content of hot rolled steel plate is slightly higher than that of cold rolled steel plate. When the components are not locked together, the density is the same. However, if the composition is very different, such as stainless steel, the density of cold-rolled and hot-rolled steel plates is about 7.9g/cm3. It also depends on the ingredients. Hot-rolled steel plates are only more ductile, and steel is also compressed. Hot rolled steel plates are divided into structural steel, low carbon steel and welded bottle steel. Then according to all kinds of steel, find the steel you need and check the density and composition of specific steel. Hot rolled steel plate has low hardness, easy processing and good ductility. Cold-rolled sheet has high hardness and relatively difficult processing, but it is not easy to deform and has high strength. Hot rolled steel plate has relatively low strength and poor surface quality (oxidation \ low finish), but good plasticity. Generally, medium plate and cold rolled plate have high strength, high hardness and high surface finish. Generally, it is a thin plate, which can be used as a stamping plate. The production process of hot rolled steel plate and cold rolled steel plate is different. Hot rolled steel plates are rolled at high temperature, while cold rolled steel plates are fried at room temperature. Generally speaking, cold-rolled steel plates have better strength and hot-rolled steel plates have better ductility. Generally, the thickness of cold rolling is relatively small, and the thickness of hot rolling can be larger. The surface quality, appearance and dimensional accuracy of cold-rolled steel plate are better than those of hot-rolled steel plate, and the product thickness is reduced to about 0. 18mm, so it is more popular. For product acceptance, you can ask professionals to do it. The mechanical properties of hot rolled steel plate are far inferior to those of cold working and forging, but it has good toughness and ductility. Cold-rolled steel plate has certain work hardening and low toughness, but it can achieve a good yield ratio. Used for cold bending spring pieces and other parts. At the same time, because the yield point is close to the tensile strength, the danger in the use process is unpredictable, and accidents are easy to occur when the allowable load is exceeded. 1) cold plate cold rolling, no scale on the surface, good quality. Hot rolled steel plate is a kind of hot rolled steel plate with oxide scale on the surface and different thickness. 2) Hot rolled steel plate has poor toughness and surface flatness, and its price is lower, while cold rolled steel plate has good ductility and toughness, but its price is more expensive. 3) Rolling is divided into cold-rolled and hot-rolled steel plates, with recrystallization temperature as the distinguishing point. 4) Cold rolling: Cold rolling is generally used to produce strip with high rolling speed. Hot rolled steel plate: the temperature of hot rolling and forging. 5) The surface of hot-rolled steel plate without electroplating is dark brown, and the surface of cold-rolled steel plate without electroplating is gray. Electroplating can be distinguished by the smoothness of the surface. The smoothness of cold-rolled steel plate is higher than that of hot-rolled steel plate.