In different environments, the surface of stainless steel pipes will change differently. After understanding the influence of the use environment on the stainless steel pipe, you can choose the appropriate model, otherwise the stainless steel pipe will rust and corrode.
Pretreatment is an important treatment step (including pickling, chemical polishing and electrochemical polishing, electroplating, passivation, blackening, coloring, chemical processing, etc.) During the forming process of stainless steel pipes, the surface may be stained with oil, burrs, rough surfaces and oxides. Therefore, prior to surface treatment, oil, burrs, uneven surfaces and oxides must be removed for subsequent treatment. Get satisfactory results.
The dirt on the surface of stainless steel pipes to be removed in the pretreatment can be divided into two categories: organic and inorganic. Organic pollutants: including mineral oils (such as diesel, motor oil, petrolatum, paraffin, etc.) and animal and vegetable oils (such as soybean oil, tea oil, rapeseed oil, lard, tallow, etc.). These oil stains mainly come from the processing of stainless steel pipes. Used lubricants, cutting oils, quenching oils, polishing and polishing pastes and fingerprints. Inorganic fouling: includes fouling, dust particles and oxides generated during heat treatment.
The pretreatment procedure of stainless steel pipe is as follows:
(1) Mechanical leveling of the surface: The roughness of the stainless steel surface is eliminated, and a certain surface finish is achieved after mechanical grinding and polishing.
(2) Degreasing: Degreasing the surface.
(3) Pickling: remove oxides on the surface.
(4) Weak corrosion: activate the surface to be treated, remove the surface passivation film, and expose the metal crystal structure.
The surface pretreatment method of stainless steel pipe is as follows:
(1) Mechanical method: Use a polishing machine, polishing machine or other machinery to remove the rough surface, then polish and polish it.
(2) Chemical method: degreasing with alkaline solution, pickling with acid solution and organic solvent to dissolve grease and decontaminate.
(3) Electrochemical method: apply electrochemical degreasing and electrochemical etching.
(4) Rolling light, centrifugal light, centrifugal plate light decoration and rotating light decoration, suitable for small parts.
(5) Sandblasting: suitable for large-scale treatment, with the functions of decontamination and scale removal.
Therefore, according to different surface conditions, appropriate pretreatment methods are adopted for the quality requirements of subsequent treatment of stainless steel pipes.