There are many problems in copper plate and strip rolling, such as "sickle bend", "edge wave", "rib wave", etc. How are these defects formed? How can we prevent it?

Defect Name: sickle bend. Due to the uneven deformation in the rolling process, sickle bending occurs when the extension of both sides of the plate and strip is different, that is, the deformation of one side is large and the deformation of the other side is small.

Specific reasons:

1. Inconsistent press down on both sides of the rolling mill;

2. Uneven heating of ingots;

3. Unreasonable distribution of cooling lubricant along the width direction;

4. Improper roll shape control;

5. Incorrect or misaligned feeding;

Elimination measures:

1. Measure the thickness frequently and check and adjust the press down on both sides;

2. Use guide ruler correctly to ensure the alignment of ingot;

3. The convexity and concavity of the roller shape are controlled on the symmetry point of the rolling roller;

4. Check the cooling and lubrication system to ensure that each nozzle works normally;

Defect Name: edge wave. It is also caused by uneven deformation in the rolling process, but when the edge deformation is large and the middle deformation is large, edge waves will appear. It is divided into unilateral wave and bilateral wave.

Specific reasons:

Unilateral wave:

1. Uneven puck thickness on both sides of blank;

2. Uneven annealing of billet;

3. The press down adjustment on both sides is inconsistent;

4. Feeding misalignment or rolling piece deviation;

5. Uneven cooling flow on both sides;

6. The wear of the rolled spokes is different, or the center vertex of the ground spokes deviates from the rolling center line;

Elimination measures:

1. Control the lateral tolerance of incoming materials;

2. The annealing of the billet shall be transversely uniform;

3. The flow and strength should be reasonably allocated along the rolling spoke surface;

4. The spokes shall be grinded and replaced in time;

5. The blank should be centered and the operation should be standardized

Specific reasons

Bilateral wave

1. The incoming material is thick in the middle and on both sides;

2. The crown of rolling web is too small;

3. The reduction of pass is too large and the tension is too small;

4. The intermediate strength of cooling sliding is too large;

Elimination measures:

1. Control the lateral tolerance of incoming materials;

2. The configuration of rolling spokes should be reasonable or timely ground and replaced;

3. Properly reduce the reduction of pass and increase the rear tension;

4. The stream must slide along Reasonably configure the flow and strength on the rolling surface;

Defect Name: rib wave. Rib wave occurs when the deformation of the strip between the width center and the edge is large.

Specific reasons:

1. Uneven thickness or performance of billet cross-section;

2. The crown of the rolling roller is trapezoidal, which is not suitable for the plate width;

3. Uneven cooling and lubrication;

4. The roller is seriously worn or it is easy to change the wide material after pressing the narrow material;

5. The pass processing rate is unreasonable;

6. The given quantity of hydraulic bending roller is unreasonable;

Elimination measures:

1. The performance of the cross-section of the incoming materials shall be uniform;

2. The grinding of roller shape should be standardized and scientific to avoid trapezoidal roller rolling;

3. Standardize the rolling procedure, and it is forbidden to continue rolling wide materials after rolling narrow materials;

4. The given quantity of the hydraulic bending roller shall be reasonably matched with the reduction of the pass;

5. The flow and strength shall be reasonably configured along the rolling surface according to the rolling plate type;

Source: copper aluminum Online