Definition and basic requirements of lubrication f

2022-08-24
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Definition and basic requirements of steel rolling (cold rolling) process lubrication

in the general configuration of steel rolling (mainly cold rolling) process, although the configuration is not as high as the high-end configuration, in order to reduce the friction between the roll and the rolled stock, reduce the rolling force and power consumption, make the rolled stock easy to extend, control the rolling temperature, and improve the quality of rolled products, it is necessary to add lubricating coolant between the roll and the rolled stock contact surface. This process is called steel rolling process lubrication

cold rolling usually uses steel coils with a thickness of 2~4mm obtained after Hot Roughing and finishing rolling and treated with acid pickling and annealing as billets, and uses multi roll mills (reversible or continuous rolling) to roll into thin plates with a thickness of 0.8mm to 0.01mm. Due to the great deformation resistance of cold metal, now how to select this type of tensile testing machine? The rolling force of chemical cold mill has reached thousands of tons, and the rolling speed is close to 2500m/min. Obviously, in such a high-speed deformation process of metal, on the one hand, due to the friction between molecules inside the metal, a lot of heat energy will inevitably be generated; On the other hand, the thinning (extension) of rolled stock inevitably causes the relative movement between the roll and the surface of rolled stock

the basic requirements of lubricants for cold rolling process are:

1 Proper oiliness, that is, under great rolling pressure, can still form a boundary oil film to reduce friction resistance and metal deformation resistance; Reduce roll wear and prolong roll service life; Increase reduction, reduce rolling passes and save energy consumption. However, from time to time, it should be considered that there must be a certain friction between the roll and the steel to make the steel bite into the roll. If the friction coefficient is too low, it will slip. Therefore, the lubrication performance must be appropriate

2 Good cooling capacity, that is, it can absorb the heat generated in the rolling process to the greatest extent to achieve constant temperature rolling, so as to maintain the stable roll shape of the roll and maintain the uniform thickness of the strip steel

3 this is mainly based on the measured experimental data And the surface of strip steel have good washing and cleaning effect. To remove impurities and dirt mixed in the outside world and improve the surface quality of steel

4. Good physical and chemical stability. In the rolling process, it will not react with the metal and will not affect the physical properties of the metal

5. Good annealing performance. In modern cold rolled strip production, in order to simplify the process, improve labor productivity and reduce costs, when intermediate annealing is required, the production process of direct annealing without degreasing and cleaning is adopted. This requires that the lubricant does not cause annealing corrosion due to its residue on the steel surface (that is, the spots on the steel surface are measured by force sensors, amplifiers and data processing systems)

6. Good filtration performance. In order to improve the surface quality of steel, some rolling mills use high-precision filtration devices (such as diatomite) to remove impurities in oil to the greatest extent. At this time, avoid the additives in the oil being adsorbed or filtered out to maintain the quality of the oil

7. Good oxidation stability and long service life

8. Good rust resistance. For short-term storage between processes, it can play a good role in rust prevention

9. It should not contain substances harmful to human health and pungent smell

10. The oil source is extensive, easy to obtain and low cost

lubrication of hot rolling process

it is a very important thing in the steel rolling process to improve the output of hot rolling strip mill, reduce consumption and improve productivity. The practice of various countries has proved that the use of hot rolling oil can significantly reduce the wear of rolls, reduce power consumption, improve the surface quality of steel plates, and improve productivity

the following benefits can be obtained by using hot rolling (which has been proved by practice):

1 The surface condition of the roll is improved

2. The unit consumption of rolls is reduced

3. The consumption of electric energy is reduced

4. The surface quality of strip steel is improved

5. Reducing the rolling pressure makes it easy to roll thin gauge strip steel

6. Promote the research of hot rolling theory. (end)

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