News

Methods of extending the service life of welded pipes


We choose the welded pipe because of its corrosion resistance and long service life, but will the welded pipe have a long service life? This is not necessarily the case. Only by understanding the performance of the welded pipe and making it reasonably used can its life be maximized.

The exposed metal surface will produce an electrochemical reaction or a chemical reaction, which will be uniformly corroded. The parts with weak corrosion resistance in the purification film on the surface of the welded pipe will form a pitting reaction due to the self-excited reaction, forming small holes, and the proximity of oxygen ions to form A strong corrosive solution that accelerates the rate of corrosion reactions. In addition, the occurrence of intergranular corrosion inside the welded pipe leads to cracking, which will pulverize the purification film on the surface of the welded pipe.



Therefore, regular maintenance of the welded pipe surface is required to ensure its clean surface and prolong its service life. When washing the surface of the welded pipe, it is necessary to carefully avoid surface scratches; it is forbidden to use bleaching powder, washing liquid containing abrasives, grinding tools for steel balls, etc.; in order to remove excess washing liquid, rinse the surface with clean water after washing.

When there is dust on the surface of the welded pipe and it is easy to remove contaminants, it can be washed with weak ionic detergent, or with alcohol or organic solvent (ether, benzene).

If there are grease or lubricating oil contaminants on the surface of the welded pipe, after wiping it with a soft cloth, wash it with neutral detergent, ammonia solution or special detergent; Then soak with ammonia solution or neutral carbonic acid and aqueous solution, or wash with neutral detergent or warm water.

When there is rainbow pattern on the surface of the welded pipe (caused by excessive use of detergent or oil), it can be washed with warm water neutral detergent when washing; when there is rust caused by pollutants on the surface of the welded pipe, it can be washed with 10% nitric acid or abrasive detergent. Can be washed with special detergents.

Note: The seamless pipe must wear labor protection equipment before pickling. The working environment on site should also be inspected in detail, mainly to check whether the sling of the steel pipe is in good condition; when pickling the seamless pipe, the pickling is mainly carried out with hydrochloric acid. Generally, the content of hydrochloric acid is 18% to 20% excellent; seamless pipe specifications are expressed by diameter * wall thickness.

Know more about this product price, catalogue, mill test certificate,  please inquiry to: sales@nan-steel.com

Contact