Quality objection case: cold and hot rolling mixed processing
Case Overview:
The customer complained that the recently purchased batch of cold rolled stainless steel flat plates had slight scratches, so they raised a quality objection.
Case Study:
Through on-site inspection, the scratches mentioned by the customer do exist, the distribution is irregular, and they are relatively slight, and it is difficult to find them if they are not in a well-lit place.
Since the scratches are in a bright state, the problem caused by the original roll can be basically eliminated, and it is likely to be a problem in the opening process. Through careful inspection of the Kaiping equipment, it was found that the surfaces of the pinch roller, conveying roller, and leveling roller of the Kaiping machine were rough, and a certain amount of ash layer adhered. The scratches are most likely caused by the steel coil when it comes into contact with these work rolls.
It turned out that the Kaiping equipment had previously processed a batch of 3.0-thick hot-rolled stainless steel coils. The surface of the hot rolled stainless steel coils was rough and dusty. After the cold-rolled flattening machine has processed a large number of steel coils, all kinds of work rolls directly in contact with the steel coils have a certain amount of wear and a lot of dust has accumulated. When the cold rolled stainless steel is processed, slight scratches are left on the surface of the steel plate. mark.
Process Result:
Due to the different properties of cold and hot rolled stainless steel, mixed processing is generally not allowed. If you have to process hot-rolled coils on cold-rolled flattening equipment, you must wipe the equipment after processing. If you find that the work roll is worn out, you can perform appropriate grinding.