3.1 Weld defects: Weld defects are serious, and manual mechanical grinding is used to make up for them. The resulting grinding marks cause uneven surfaces and affect the appearance. 3.2 Surface inconsistency: Only pickling and passivation of the weld seam also causes uneven surface and affects the appearance. 3.3 Scratches are difficult to remove: the overall pickling passivation can not remove all kinds of scratches generated during processing, and can not remove carbon steel, spatter and other impurities adhered to the surface of stainless steel due to scratches and welding spatter. Causes chemical corrosion or electrochemical corrosion to rust in the presence of corrosive media.
3.4 Uneven grinding and polishing passivation: pickling and passivation treatment after manual grinding and polishing, it is difficult to achieve a uniform treatment effect for large-area workpieces, and it is impossible to obtain an ideal uniform surface. And the cost of working hours and the cost of auxiliary materials are also higher. 3.5 Pickling ability is limited: pickling passivation paste is not a panacea, and it is difficult to remove the black oxide scale produced by plasma cutting and flame cutting. 3.6 The scratches caused by human factors are relatively serious: in the process of hoisting, transportation and structural processing, the scratches caused by human factors such as bumping, dragging and hammering are relatively serious, which makes the surface treatment more difficult, and is also the cause of rust after treatment. main reason. 3.7 Equipment factors: During the bending and bending process of profiles and plates, the scratches and creases caused are also the main reasons for the rust after treatment. 3.8 Other factors: In the process of purchasing and storing stainless steel raw materials, bumps and scratches caused by hoisting and transportation are also relatively serious, which is also one of the reasons for corrosion.
