The customer complained that the batch of stainless steel plates purchased had obvious upturns on the board, which affected its use. Therefore, quality objections were raised.
case analysis:
The lot purchased by the customer is 304.1, thickness is 4.0mm, and the specification is 1500×6000mm. Through the on-the-spot inspection, these slabs do have plate upturns, and there are still more obvious side waves on the plate itself.
The upturn of the board is generally caused by the excessive amount of flattening rolls at the time of opening. For a variety of thickness of steel coils, Kaiping reduction has a corresponding set of parameters, in general, there will be no such quality problems, so consult the processing records.
In the Kaiping process, since the flat plate itself has large side waves, the operator has increased the amount of pressing by a large amount in order to improve the wave phenomenon of this side, resulting in the upward tilt of the plate.
In fact, the increase in the amount of reduction did not bring about much improvement in the side waves. This medium plate Kaiping equipment leveling roller diameter is relatively coarse, there is no intermediate roller fine-tuning function, so the basic for the coil wave is powerless, especially the coil thickness of 3.0 ~ 4.0mm. The consequences of increasing the amount of reduction often only allow the head of the steel plate to be upturned, and it also has some damage to the equipment itself.
process result:
Strict implementation of operating procedures, for these large waves of the wave, and in the case of confirmation can not be well improved, should notify the customer before processing, ask the customer's opinion before processing.