What are the rolling mills in China, both hot and cold rolling, and it is best to give a list? Urgen

Summary. Performance: In general, the mechanical properties of the hot plate and the cold plate in the project are considered to be indistinguishable, although the cold plate has a certain work hardening in the cold rolling process, (but it is not excluded that the mechanical properties are strict, then it needs to be treated differently), the cold plate is usually slightly higher than the yield strength of the hot plate, and the surface hardness is also higher, how to see the degree of annealing of the cold plate.

But no matter what, the strength of annealed cold plate is higher than that of hot plate.

What is the difference between hot rolling and cold rolling of steel, in terms of price and practicality, thank you.

Performance: In general, the mechanical properties of the hot plate and the cold plate in the project are considered to be indistinguishable, although the cold plate has a certain work hardening in the cold rolling process, (but it is not excluded that the mechanical properties are strict, then it needs to be treated differently), the cold plate is usually slightly higher than the yield strength of the hot plate, and the surface hardness is also higher, how to see the degree of annealing of the cold plate. But no matter what, the strength of annealed cold plate is higher than that of hot plate.

Generally speaking, cold-rolled products are more expensive than hot-rolled, of course, the performance is good, because cold-rolled products have higher dimensional accuracy, surface quality and process performance.

Hot-rolled steel is a steel rolled by high temperature heating, its strength is not very high, but it is enough to meet our use, its plasticity, weldability is good, so we are more commonly used; Cold-rolled steel is an ordinary hot-rolled steel that has been drawn by strong hot-rolled steel force to exceed the strain hardening stage, and its strength is very high, but the toughness and weldability are poor, and it is relatively hard and brittle!

Cold-rolled steel is steel that is produced by cold rolling. Cold rolling is the process of further thinning the steel plate to the target thickness at room temperature. Compared with hot-rolled steel plate, cold-rolled steel plate has a more accurate thickness, smooth and beautiful surface, and also has a variety of superior mechanical properties, especially in terms of processing performance.

Because the cold-rolled original coil is relatively brittle and hard, it is not suitable for processing, so under normal circumstances, the cold-rolled steel plate is required to be annealed, pickled and surface-smoothed before being handed over to the customer. The maximum thickness of cold-rolled steel is below, such as the thickness of cold-rolled steel plate in most factories is below; The minimum thickness and width are determined according to the equipment capacity and market demand of each plant.

Hello: The main difference between cold rolling and hot rolling is whether the rolling temperature is above the recrystallization temperature.

The so-called hot rolling is to roll above the metal recrystallization temperature, and the recrystallization of grains will occur at the same time during the deformation process of the metal to obtain a finer economic structure. At the same time, the deformation resistance of the metal will be lower than that of cold rolling, and greater deformation rolling can be achieved.

The so-called cold rolling is rolled below the metal recrystallization temperature, and the metal deformation process is mainly composed of the slip of the metal and the plugging of dislocations. Due to the blockage of dislocations, the yield limit of the metal increases, but the plasticity decreases relatively. This is also known as work hardening.

The surface of cold-rolled steel is high, the product size is fine, the thickness is uniform, and the plate shape is straight; Thin strips that cannot be produced by the hot rolling method can be obtained; The disadvantage is that in the cold rolling process, there is a large internal stress inside the material, so it is easy to twist and deform in the processing process.

The hot-rolled steel products have good comprehensive properties and good deep drawing properties; But the surface quality is not as good as cold-rolled steel.

1. Appearance and surface quality: Because the cold plate is obtained by the hot plate after cold rolling, and some surface finishing will be carried out by cold rolling, the surface quality of the cold plate is relatively good. For products with high coating quality requirements, such as subsequent painting, cold plates are usually chosen.

Uncut plates usually have a layer of oxide on the surface, black, or a layer of ferric tetroxide. In layman's terms, it's like brown, and if the storage environment is not good, it usually rusts.

2. Performance pants: Under normal circumstances, the mechanical properties of the hot plate and the cold plate are considered to be the same in the project. Although cold plate has a certain degree of hardening during the cold rolling process, the elastic limit of cold plate is usually slightly higher than depending on the degree of annealing of the cold plate, and its surface hardness is also higher.

However, the strength of annealed cold plates is higher than that of hot plates.

3. Forming performance: Since there is basically no difference between the performance of the hot plate and the cold plate, the factors affecting the formability depend on the surface quality. However, since the surface quality is better than that of the cold plate, the steel plate of the same material is usually used, and the forming effect of the cold plate is better than that of the hot plate.

Cold rolled steel and hot rolled steel refer to steel manufactured under different process conditions, and there are the following differences between them:

1.Production process: cold-rolled steel is processed and pressed at room temperature, while hot-rolled steel is processed and pressed at high temperature. Specific process parameters and operating procedures also vary.

2.Material properties: Due to different processes, the physical properties and mechanical properties of cold-rolled steel and hot-rolled steel are different.

Cold-rolled steel has high strength and hardness, good corrosion resistance, but relatively low plasticity. Hot-rolled steel undergoes high temperature treatment during processing, and has good plasticity and toughness.

3.Surface quality: The surface of cold-rolled steel is usually smooth, flat, has good dimensional accuracy, and is usually free of oxide scale or rust. There may be some oxide scale, rust or flakes on the surface of hot-rolled steel.

4.Size control: Due to the characteristics of the cold-rolled process, the dimensional accuracy of cold-rolled steel is relatively high, the length is more stable, and the diameter and wall thickness are better controlled. Hot-rolled steel, on the other hand, undergoes a large deformation at high temperatures, with relatively low dimensional accuracy, and there may be certain deviations.

5.Application fields: cold-rolled steel is mostly used in fields that require high dimensional accuracy, strength and hardness, such as automobile reputation and simple car manufacturing and machinery.

1. Appearance and surface quality: Since the cold plate is obtained by the hot plate after the cold rolling process, and the cold rolling will also carry out some surface finishing, the cold plate is better than the hot plate in terms of surface quality (such as surface roughness, etc.), so if there are higher requirements for the coating quality of the product such as post-painting, the cold plate is generally selected. In addition, the hot plate is divided into pickled plate and non-pickled plate, the surface of the pickled plate is normal metal color due to pickling, but the surface is not cold-rolled so the surface is still not as high as the cold plate, and the surface of the non-pickled plate usually has an oxide layer, black, or there is an iron tetroxide black layer.

In layman's terms, it is as if it has been roasted by fire, and if it is stored in a bad environment, it will usually have a little rust.

2. Performance: Under normal circumstances, the mechanical properties of the hot plate and the cold plate in the project are considered to be indistinguishable, although the cold plate has a certain work hardening in the cold rolling process, (but it is not excluded that the mechanical properties are strict, then it needs to be treated differently), the yield strength of the cold plate is usually slightly higher than that of the hot plate, and the surface hardness is also higher. But no matter what, the strength of annealed cold plate is higher than that of hot plate.

3. Forming performance: because the performance of the cold and hot plates is basically not too much, the influencing factors of the forming performance depend on the difference in their surface quality, because the surface quality is better than that of the cold plate, so generally speaking, the steel plate of the same material, the forming effect of the cold plate is better than that of the hot plate.