1. Weld defect: the weld defect is serious, and manual mechanical grinding method is adopted to make up for it, resulting in uneven surface and affecting aesthetics.
2. Surface inconsistency: only the weld is acid-washed and passivated, resulting in uneven surface and aesthetic effect.
3.scratch, difficult to remove: overall pickling passivation, and machining process of various scratches cannot be removed, and also can't remove adhesion due to scratches, welding spatter on the surface of the stainless steel, carbon steel, the impurities such as splash, resulting in corrosion medium existence condition of the distributed biochemistry corrosion and electrochemical corrosion and rust.
4.fine polishing passivation uneven: manual grinding polishing after pickling passivation treatment, on the workpiece with larger area, it is difficult to achieve uniform processing effect, not the ideal uniform surface. And the time cost, the auxiliary material cost is also high.
5. Limited capacity of pickling: pickling passivation cream is not omnipotent. It is difficult to remove the black oxide skin produced by plasma cutting and flame cutting.
6.for the factors caused by the scratch is serious: in the process of lifting, transportation, and structure, dragging, hammer knock against, serious scratches caused by human factors, such as harder to make surface treatment, but also the main reason of corrosion after processing.
7.Equipment factors: scratches and creases caused in the process of profile bending and sheet bending are also the main causes of corrosion after treatment.
8.Other factors: during the purchase and storage of stainless steel materials, the scratches and scratches caused by hoisting and transportation are also serious, which is also one of the causes of corrosion.