chemical polishing
Chemical polishing
Chemical polishing mechanism
Chemical polishing is when the surface of a metal is polished and smooth by regular dissolution. In the process of chemical polishing, the passivated oxide film is formed on the surface of steel parts and the oxide film is dissolved continuously, and the former is stronger than the latter. Due to the microcosmic inconsistencies of the surface of the parts, the convex part of the surface is preferentially dissolved, and the dissolution rate is higher than that of the concave part. Moreover, the dissolution of the film and the formation of the film always happen at the same time, but the rate is different. As a result, the surface roughness of the steel parts can be smoothed, so as to obtain a smooth and bright surface. Polishing can fill in surface pores, scratches and other surface defects, thereby improving fatigue resistance and corrosion resistance.
Principle of electrochemical polishing
Electrochemical polishing is also known as electrolytic polishing. Electrolytic polishing takes the thrown workpiece as the anode, the insoluble metal as the cathode, and the two poles are immersed in the electrolytic cell at the same time. Through the direct current electricity, selective anode dissolution is generated, so that the workpiece surface brightness increases and the mirror effect is achieved.
Process flow
Chemical (or electrochemical) oil removal → hot water washing → flow washing → Rust removal (10% sulfuric acid)→ flow washing → chemical polishing → flow washing → neutralization → flow washing → transfer to the next surface treatment process
Working environment: traditional polishing process working environment is harsh, polishing process produces sand, iron filings, dust, serious pollution of the environment;
Processing efficiency: manual polishing;
Laying consumption: polishing needs to consume polishing wheel, abrasive, sand belt and other auxiliary materials;
Adaptability: Polishing can be processed flat surface and other simple surface, for curved surface can not be processed. If processing R - arc, curved surface and other complex surface.
post-processing
Chemical polishing after treatment
Chemical polishing of steel parts can be used as a pre-treatment process for protective decorative electroplating, or as a pre-treatment process for chemical film formation, such as phosphating phelan. If not electroplating or chemical film, and direct application, can be sprayed amino varnish or acrylic varnish, after drying better protective decorative effect. If spray paint before immersion rust passivating water solution, corrosion resistance will be further improved.