Weld defects: weld defects are serious, manual mechanical grinding processing method is used to compensate, resulting in grinding marks, resulting in uneven surface, affect the appearance.
Inconsistent surface: only pickling and passivation of the weld will cause uneven surface and affect the appearance.
Scratches are difficult to remove: overall pickling passivation, can not be processed in the process of all kinds of scratches removed, and can not remove due to scratches, welding splashes and adhesion on the surface of stainless steel carbon steel, splashes and other impurities, resulting in the presence of corrosive media under the condition of chemical corrosion or electrochemical corrosion and rust.
Uneven polishing and passivation: pickling passivation treatment is carried out after manual polishing and polishing. It is difficult to achieve uniform and consistent treatment effect for large forgings, and an ideal uniform surface can not be obtained. And the cost of working hours, auxiliary materials are also higher.

Pickling capacity is limited: pickling passivation paste is not, for plasma cutting, flame cutting and black oxide, it is difficult to remove.
Scratches caused by human factors are more serious: in the process of lifting, transportation and structural processing, scratches caused by knock, drag, hammer and other human factors are more serious, which makes the surface treatment more difficult, and is also the main reason for corrosion after treatment.
Equipment factors: in profile, plate bending, bending process, caused by scratches and creases is also the main reason for corrosion after treatment.
Other factors: stainless steel forgings in the procurement, storage process, due to lifting, transportation process of bump and scratches are more serious, is also one of the causes of corrosion.