When cold rolling of stainless steel plate is carried out, there are mainly the following four influencing factors
Friction coefficient
Rolling lubricants must be added during the production of stainless steel cold rolling mills, especially when rolling on multi-roll mills. There are two purposes. On the one hand, it is to reduce the friction coefficient on the contact surface between the roll and the stainless steel strip, reduce the rolling pressure and transmission force, and improve the surface state of the stainless steel strip; on the other hand, it is used to cool the roll and the stainless steel strip. Take away the deformation heat generated in the rolling process and keep the rolling mill at normal working temperature for a long time.
Production tension
The tension during cold rolling production will have a great influence on the rolling pressure, and will also affect the shape and thickness of the stainless steel. Multi-roll mills use high tension rolling, and the tension required for cold rolling of stainless steel strips will be greater. On a single-stand reversing rolling mill, the tension is formed between the rolling mill and the coiler; the coiler that forms the front tension is in the electric working state, and the coiler that forms the back tension is the working state of power generation. In the rolling process, constant tension control is usually used to keep the tension unchanged, because the diameter of the coil of the front coiler is getting larger and larger, so the coiler will slowly decelerate; The diameter is getting smaller and smaller, so increase the speed slowly to ensure that the corresponding line speed does not change significantly.
Rolling speed
The change of rolling speed during cold rolling production will affect the friction coefficient between the roll and the stainless steel strip, which in turn will affect the change of the rolling pressure and the thickness of the stainless steel strip. The rolling speed of the multi-roll mill is relatively fast, and the rolling speed of the modern twenty-high mill can be as high as 800m/min and 1000m/min. The higher rolling speed requires the hot-rolled stainless steel strip to have completely excellent metal properties, because the influence of high-speed rolling on material defects will be higher than the influence of low-speed rolling on material defects, which makes the rolling equipment and products subject to comparison. big damage. Therefore, a lower rolling speed should be used in the first pass of rolling to facilitate accurate inspection of the rolled stainless steel strip, and to record the defect positions that easily affect the high-speed rolling.
Roll
Cold rolling mills have high requirements on the hardness, strength and wear resistance of the rolls, and also have good toughness. The roll materials used in the multi-roll cold rolling mill are high-chromium steel and high-speed steel. Different parts of the rolls should also use different compositions of steel. In order to ensure that the surface quality of cold-rolled products meets the corresponding requirements, there are also very high requirements for the surface of the work roll, which must have a certain roughness and must not have any visible defects, such as craters, cracks, etc. Rolls need to be finely ground and inspected before they can be used. During the rolling process, it is also necessary to check regularly. If a problem is found, the roll needs to be replaced immediately. In actual production, the replacement of the roll is very frequent and necessary.
