A composite surface treatment method for repairing the passivation state of rusted stainless steel

Abstract

The invention belongs to the field of treatment of stainless steel surfaces, in particular to a treatment method for repairing a rusty stainless steel passivated composite surface. According to the treatment method for repairing the rusty stainless steel passivated composite surface, an electrochemical passivation and self-assembly molecular film technique combined treatment method is adopted for a rusty stainless steel product, and electrochemical passivation is conducted below a protective potential, so that continuation of original pitting corrosion is not stimulated, and a complete and compact passivating film on the rusty stainless steel surface can be reconstructed; and in addition, the repaired passivating film is maintained by means of a self-assembly molecular film and kept stable. After electrochemical passivation and self-assembly molecular film treatment, the corrosion resistance of the stainless steel product is remarkably improved. The electrochemical passivation technique adopted by the treatment method is small in risk, high in safety performance, good in passivation effect, easy and convenient to implement and high in engineering applicability, can be an important means for repairing and maintaining the rusty stainless steel product, and has great social benefits and economic benefits.

Description

technical field [0001] The invention belongs to the field of stainless steel surface treatment, in particular to a composite surface treatment method for repairing the passivated state of rusted stainless steel, which can repair and protect corroded stainless steel products. Background technique [0002] Stainless steel has been widely used in practice because of its good corrosion resistance. The basis of its corrosion resistance is the surface passivation mechanism, that is, the formation of a passivation film on the surface of stainless steel that can reduce the chance of corrosion. However, stainless steel does not mean that it remains "stainless" in all circumstances. Therefore, in the process of actual use, if you do not pay attention to the use range and operation requirements of stainless steel to cause damage to the passivation film, stainless steel will still corrode, especially localized corrosion. The destruction and sudden incidents of stainless steel equipmen...

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Problems solved by technology

It can be seen from the patent that it adopts the method of alternating electric field repair and post-treatment. Although this method is a repair treatment for local corrosion of metal materials, for on-site operations, the use of alternating electric field increases the engineering difficulty and reduces the cost. Possibility of scale application

At the same time, the characteristic of protection potential Ep, which should be paid special attention to local corrosion, has not been elaborated. If the passivation potential E is greater than the protection potential Ep, it may lead to the situation that other stainless steel surfaces other than pitting corrosion are passivated, and pitting corrosion The part is stimulated to grow inward, and the speed is extremely fast; if the passivation potential is too small, the passivation film on the surface of the stainless steel may not be complete and compact

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