What is cold rolling? What are the advantages?
Cold rolling is to heat the steel billet to a temperature below the general heating temperature and then roll it a temperature below the general hot rolling temperature. More specifically, it is medium temperature rolling. The main purpose is to greatly reduce the fuel consumption of steel billet heating and the loss metal burning.
The old rolling mill has a low rolling speed, and the medium temperature drops significantly during rolling, so the initial rolling temperature is greatly increased. After the speed of the new rolling mill is improved, the deformation heat generated during rolling basically does not change, or even rises, which creates conditions for cold rolling.
Cold refers to rolling below the existing hot rolling temperature. Cold rolling can not only reduce energy consumption and metal burning, but also improve product quality and generate huge economic benefits.
are usually two cold rolling procedures for bars, first, taking advantage of the characteristics of small temperature drop or small temperature rise of the continuous rolling mill, the initial combustion temperature is from 1000~1100 to 850~950. There is almost no difference between the rolling temperature and the starting rolling temperature. improve the strength of the rolling mill, it is necessary to increase the motor power and rolling energy consumption. However, by reducing the heating temperature, fuel can be saved, and about20% of the energy can be saved after comprehensive balance.
Secondly, the unit interval cooling section is not only used to reduce the initial rolling temperature, but to reduce the final rolling temperature to below the recrystallization temperature (700~800), and the deformation heat treatment process with the completion of deformation of 0% ~ 50%, the grain refinement, uniform organization, and the improvement of the mechanical properties and welding properties of the steel are better than the traditional heat treatment method Therefore, modern rolling mills often expand the distance between units, sometimes use large separators, and sometimes increase intermediate cooling water boxes. The grain size can be controlled in the cold rolling, and the main limitation of cold rolling is that the rolling mill and the driving main motor are designed according to the existing design parameters, so the equipment capacity is insufficient.
Cold rolling refers to rolling at a temperature below the temperature of the usual hot lead, which is also called medium temperature rolling or warm rolling abroad. Its purpose is to greatly the fuel consumed in the heating of the steel billet and to reduce the loss of metal burning. According to foreign reports, the production energy consumption of ordinary wire rod rolling mills is 650 kWh/t, which needs to be heated to 520 kWh/t to 1150. The energy required for rolling is only 110 kWh/t, according to the production test of 10.5 mm acute angle steel for 70 mm medium carbon steel (ssl650 in Pagssta factory in Sweden. The rolling energy at 70 points is about 182 kWh/t lower than that at 1150 points without burrs and surface defects. When rolling alloy steel such as spring steel, bearing steel, tool steel and stainless steel at low temperature, it can be rolled normally within the range 800 ~ 950 y, saving 85 ~ 130 kwh/t.