Views:1 Author:Site Editor Publish Time: 2021-11-05 Origin:Site
Hot-rolled steel is a steel made by high-temperature heating and rolling. Its strength is not very high, but it is sufficient for our use. Its plasticity and weldability are better, so we are more commonly used.
Hot rolling is the need to heat the material during or before rolling. Generally, it is heated to above the recrystallization temperature before rolling.
Ironmaking→Steelmaking→Continuous casting (or die casting)→Hot rolling (to produce hot-rolled products)→Cold rolling (to produce cold-rolled products)
In addition to the size factor, it can generally be distinguished from the surface color and quality. The hot-rolled steel is the one with obvious oxidation color, and the cold-rolled steel is the smooth and shiny surface. You can also use a hard object to describe the surface to make a simple distinction. Hot-rolled steel is easy to scratch, cold-rolled steel (harder hardness is higher) is not easy to scratch.
Cold rolled steel is steel produced by cold rolling. Cold rolling is a steel sheet that is further thinned to a target thickness under room temperature conditions. Compared with hot-rolled steel sheets, cold-rolled steel sheets are more accurate in thickness, and have a smooth and beautiful surface. At the same time, they also have various superior mechanical properties, especially in terms of processing properties.
cold-rolled steel is ordinary hot-rolled The steel that has undergone strong drawing beyond the strain hardening stage has high strength, but its toughness and weldability are poor, and it is hard and brittle!
The difference between cold-rolled steel and hot-rolled steel is not in the smelting process, but in the rolling temperature, or the end temperature of the rolling. The final rolling temperature is lower than the recrystallization temperature of the steel to become cold rolled steel. Hot-rolled steel is easy to roll, and the rolling efficiency is high. However, under hot-rolling conditions, the steel is oxidized and the surface of the product is dark and gray. Cold-rolled steel requires large mill power and low rolling efficiency. In order to eliminate work hardening during the rolling process, intermediate annealing is required, so the cost is also high. However, cold-rolled steel has a bright surface and good quality, which can be directly used for processing. The finished product, especially the cold-rolled steel plate is widely used.