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Kính chào tất cả anh/ chị. Em hiện đang làm trong ngành tôn thép, em gặp một vấn đề nan giải là tôn sau khi mạ nhúng nóng có hiện tượng co lõm nhưng chưa có giải pháp xử lý. Mong anh/ chị có kiến thức trong ngành cho em lời khuyên. Em xin cảm ơn.
(My problem: Defect of Non-zinc filling/ pock-marked appear on both of surface after coating, which looks like not filling the coating with a size of 1 - 3 mm. It appears even in galvanizing and galvalume. I have tried to overcome it in many ways, including: cleaning inside furnace's sections: jet cooling, exit, snout; reducing the air knife pressure, reducing the speed of the cooling blower, supply 25% of HNx concentration, the temperature of the first deflector after pot is lower 250 degrees,... But after all, I can not solve above problem.
The thicker coating mass, the more obvious dents. What is the cure? Please help me.
The photos have been attached for clear understanding the problem.
(My problem: Defect of Non-zinc filling/ pock-marked appear on both of surface after coating, which looks like not filling the coating with a size of 1 - 3 mm. It appears even in galvanizing and galvalume. I have tried to overcome it in many ways, including: cleaning inside furnace's sections: jet cooling, exit, snout; reducing the air knife pressure, reducing the speed of the cooling blower, supply 25% of HNx concentration, the temperature of the first deflector after pot is lower 250 degrees,... But after all, I can not solve above problem.
The thicker coating mass, the more obvious dents. What is the cure? Please help me.
The photos have been attached for clear understanding the problem.
