Ultrathin cold rolling strips are of high value while requiring strict production control. There are many shape issues affecting the product quality. Below are some factors that cause the shape defects and the relevant measures to make our cold-rolled coils in good shape.

Factors affecting shape and quality:

1. Fluctuation of roll bending force;

2. Uneven thermal expansion of rollers;

3. High rolling pressure affecting shape adjustment;

4. Much contact between the rollers and the cold-rolled strips

Relevant measures:

1. Testing the hydraulic fluid, filtering the large particle substances and change the filtering core to lower the roll bending force;

2. Optimize the rolling speed (＜400m/min) and adjusting the pre-heating time (＞25min);

3. Concentration of emulsion improved from 1.0%～2.0% to 1.8%～2.5%, heat-preservation temperature during the re-rolling process increased from 620℃ to 640℃;

4. Assure the rolling precision of rollers.