Problems in the processing of stainless steel welded pipe products
3.1 weld defects: weld defects are more serious, the use of manual mechanical polishing processing method to make up, resulting in the grinding marks, resulting in uneven surface, affecting the appearance.
3.2 the surface is not consistent: only for the welding of pickling passivation, but also cause the surface is not uniform, affecting the appearance.
3.3 scratch difficult to remove: pickling and passivation for overall, nor will remove scratches produced in the machining process, and can not be removed due to scratching, welding spatter and adhesion of impurities in the surface of stainless steel carbon steel, welding spatter, resulting in corrosion medium under chemical corrosion and electrochemical corrosion and rust.
3.4 polishing and passivation is not uniform: after polishing and passivation treatment, the area of the larger workpiece, it is difficult to achieve uniform treatment effect, can not get the ideal uniform surface. And man hour cost, auxiliary material cost is also high.
3.5 pickling capacity is limited: acid pickling passivation cream is not a panacea, the plasma cutting, flame cutting and production and black oxide skin, more difficult to remove.
Scratch the 3.6 caused by human factors more serious: in lifting, transportation and processing process, bump, procrastination, hammer et al caused by scratching is more serious, making the surface processing more difficult, but also after the treatment of corrosion of the main reason.
3.7 equipment factors: in profiles, sheet metal bending, bending process, caused by scratching and crease is produced after corrosion.
3.8 other factors: stainless steel raw materials in the procurement, storage process, due to the lifting and transport process of bump and scratch is also more serious, also produce one of the cause of corrosion.
4 preventive measures should be taken
4.1 storage, lifting and transportation
4.1.1 stainless steel welded pipe storage: should have special storage rack, storage rack should be wood or surface painted carbon steel stent or pad with a rubber pad, and carbon steel and other metal materials. Storage, storage location should be easy to lift and transport, and other materials storage area relatively isolated, there should be protective measures, in order to avoid the pollution of dust, oil and rust on the stainless steel.
4.1.2 stainless steel welded pipe hoisting: when lifting, should use special sling, such as lifting belt, special clip etc., prohibited the use of wire rope so as not to scratch the surface; and placed in lifting and should be avoid shock bump caused by scratching.
4.1.3 stainless steel welded pipe transport: transport, application of means of transport (such as car, storage battery car) and should be clean isolation protection measures to prevent dust, oil, rust pollution stainless steel. No drag, avoid the bump and scratch.
4.2.1 processing area: stainless steel welded pipe processing area should be relatively fixed. Stainless steel parts processing area of the platform should take isolation measures, such as laying on the rubber pad, etc.. Location management, stainless steel pipe processing zone civilized production should be strengthened, in order to avoid the damage and pollution of stainless steel.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)