The black spots on the titanium strip are mainly related to the ability of cold rolling emulsion and degreasing cleaning to remove particles on the strip surface. Therefore, to improve this point, the main consideration is to improve the cleanliness of the emulsion and enhance the ability of degreasing to clean the particles on the surface of the strip. Corresponding measures are taken for these two aspects to realize the control of black spot defects.
In order to improve the cleanliness of the titanium strip emulsion, stable rolling oil was used in the test, but the rolling force increased too much. The main role of the emulsion during rolling is lubrication and cooling, of which lubrication is the most important, to achieve a balance between the lubrication performance and cleanliness of the emulsion, and the final rolling oil model should be replaced with a semi-stable type.
In addition, dirt such as "titanium soap" will inevitably appear in the rolling process of titanium materials. In order to further improve the cleanliness of the emulsion, the filter paper mesh number of the Hoffman filter is increased from 100 mesh to 120 mesh. The ability to filter large particles of dirt in the emulsion, and at the same time ensure that the flow of the emulsion can meet the normal rolling requirements of the rolling mill. The actual test results are good.
When degreasing the black spots on the titanium belt material, in order to enhance the cleaning ability of the roller brush, it is necessary to increase the density of the brush wire and use the brush wire with higher rigidity. Subsequently, the defective rate of black spots of cold-rolled coils was 5%, which was 50% lower than that before the improvement, and the defective rate of black spots was significantly reduced. And the minimum value is less than 1%, and the maximum value is less than 15%, achieving stable control of black spot defects.
