Stainless steel products in modern life more and more widely used, but also constitute a stainless steel heating time scale, although there is no oxidation of carbon steel forgings on thick-skinned, but with a strong adhesion to the base metal and very strong, making molds and cutting tools are fast wear. Thus, between the preform and final forging before machining shall eradicate the scale clean. Pickling and blasting are better finishing way to forging the first pickled and then blasting the best way.
1. Sandblasting
Sandblasting and finishing equipment (sandblasting machine) is the choice of compressed air as the power to constitute a high speed eruption beam will spray material (shot glass beads, steel shot, grit, quartz sand, silicon carbide, iron sand, sea sand) high-speed eruption to be mechanical properties of the workpiece need to dispose of appearance, laser cutting machine laser cutting equipment iron channels outside the exterior appearance of the workpiece changes episodes, because the appearance of the workpiece abrasive impact and cutting effect, so the appearance of the work is eligible for cleanliness and do not necessarily as roughness, so that the mechanical properties of the workpiece is improved appearance, thus progressed fatigue resistance of the workpiece, and it increases the adhesion between the coating.
2. Pickling
Pickling generally refers to a way to clean metal appearance.
Parts immersed in an aqueous solution of sulfuric acid is usually such as to remove the metal surface of the oxide film. Before disposal or disposal center plating, enamel, rolling and other technologies.
(A) the use of an acid solution to remove the oxide scale and rust on steel exterior material called pickling solution. Scale, rust and other iron oxides (Fe3O4, Fe2O3, FeO, etc.) with an acid solution chemical reaction onset form salts dissolved in the acid solution is removed. Pickling acids are sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, chromic acid, hydrofluoric acid and a mixed acid. The most commonly used is sulfuric acid and hydrochloric acid. The main technology immersion pickling pickling, acid pickling paste eruption rust law. More generally by dipping pickling, mass production method can be used eruption. Steel parts usually 10% to 20% (by volume) solution of sulfuric acid at a temperature of 40 ℃.
When the iron content of the solution beyond 80g / L, ferrous sulfate exceed 215g / L, should be replaced by pickling. At room temperature, a solution of hydrochloric acid and 20% to 80% (by volume) of steel pickling, corrosion and hydrogen embrittlement easily episodes appearance. Because the effect of acid on metal corrosion greatly increased demand inhibitor. After cleaning the metal surface into a silvery white, along with passive appearance, corrosion resistant stainless steel in order to progress.
(B) In order to eliminate the appearance of diatomite carrier absorption, reduce peak tailing, carriers need before applying for pickling or caustic disposal. Pickling is the carrier with 6mol / L hydrochloric acid digestion 2h or concentrated hydrochloric acid heated digester 30min, filtered, washed with water until neutral, dried. Pickling can get rid of iron, aluminum, calcium, magnesium and other impurities on appearance, but can not get rid of silanols. Pickling suitable vehicle for analysis acidic samples.

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