What are the advantages of hot rolling?

Answer 1

Hot rolled steel is steel that is rolled out when it is hot. We often see clips of sheets, slabs or bars of red-hot steel being rolled to give them a required shape. As steel becomes hotter, it can behave in a more plastic way and can be more easily sized and shaped by the rollers. We see flat sheets or long bars and rods of steel come out of the rollers. Railroad track is hot rolled to make it into the shape we know.

We know that steel that is hot rolled will be more flexible than cold rolled steel because the hot-rolled steel has larger crystal structure. Cold rolling creates smaller crystals in the matrix, and that makes cold-rolled steel stronger and harder, but less flexible. If the cold rolling process is not carefully monitored, the steel can become brittle and can be hard to work with.

Answer 2

Hot rolling of steels means doing a metal forming operation above the recrystallisation temperature. during this process the grains(view a metal through microscopes you can see them. they are not just a single atom or molecule) elongated in the direction of the rolling and as the temperature falls below recrystallisation temperature they get reformed.hot rolling increases the ductility,toughness,resistance to shock and vibration.

cold rolling of steels causes the grains to remain elongated in the direction of rolling since it is done mostly in room temperatures and slightly higher temperatures. cold rolling requires high pressure as the steels are in a very rigid form in room temperature, unlike the hot rolled steels which require very less pressure because at this time the steel resembles a bubble gum or a dough made of wheat.cold rolling induces residual stresses,distortion of grains, increase in tensile strength and hardness,smooth surface finish, accurate dimensions,high stiffness,also improves machinability of the material by conferring the property of brittleness.

Answer 3

The termination temperature of hot rolling is generally 800 to 900°C, and then it is generally cooled in air, so the hot rolling state is equivalent to normalizing treatment. Most steel materials are rolled by hot rolling. The steel delivered in the hot-rolled state has a layer of oxide scale formed on the surface due to the high temperature, so it has a certain degree of corrosion resistance and can be stored in the open air. However, this layer of oxide scale also makes the hot-rolled steel surface rough and the size fluctuates greatly. Therefore, it is required to use hot-rolled semi-finished products or finished products as raw materials and then cold-rolled production. Advantages: fast forming speed, high output, and does not damage the coating, can be made into a variety of cross-sectional forms to meet the needs of use conditions. The process of Shanghai Changzeng's hot-rolled plate has been recognized by the industry, and if you want to buy hot-rolled plates, look for Shanghai Changzeng.

Answer 4

we get better surface finish & also specimen produced by cold rolling are almost get the exact required dimension.

Answer 5

The initial breakdown of ingot into blooms and billets. And to get maximum plastic deformation unlike that of cold rolling.