Steel Pipe Supplier-GNEE
According to the production method, seamless steel pipe can be divided into hot-rolled seamless steel pipe, cold-rolled seamless steel pipe, cold-drawn seamless steel pipe, extruded seamless steel pipe, top pipe and so on. According to the sectional shape, seamless steel pipe is divided into two kinds of round and shaped, and the shaped pipe has square, oval, triangle, hexagonal, melon, star, and a variety of complex shapes with finned pipe. The maximum diameter is up to 900mm, and the minimum diameter is 4mm. according to different applications, there are thick-walled seamless steel pipe and thin-walled seamless steel pipe. Seamless steel pipe is mainly used as petroleum geological drilling pipe, petrochemical cracking pipe, boiler pipe, bearing pipe, and high-precision structural steel pipe for automobile, tractor, aviation.
1. Seamless pipe pickling commonly used media:
Sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid. When pickling, it is necessary to add pickling corrosion inhibitor to prevent the corrosion of acid on metal.
2. Seamless pipe pickling process
There are mainly impregnation pickling method, spray pickling method and acid paste descaling method. Generally use the impregnation pickling method, mass production can be used in the spray method. Iron and steel parts are generally in 10% to 20% (by volume) sulfuric acid solution pickling, the temperature is 40 ℃. When the solution contains more than 80g / L of iron, ferrous sulfate more than 215g / L, the pickling solution should be replaced. At room temperature, 20% to 80% (by volume) of the hydrochloric acid solution for pickling of steel, not easy to overcorrosion and hydrogen embrittlement phenomenon. Due to the corrosive effect of acid on metal, it is necessary to add corrosion inhibitors. After cleaning, the metal surface becomes silver-white, while passivating the surface to improve the stainless steel k corrosion ability. In order to x in addition to diatomaceous earth carrier surface adsorption, to reduce the chromatographic peaks dragged, the carrier in the use of the carrier before the need to carry out acid or alkaline cleaning treatment. Acid washing is the carrier with 6mol / L hydrochloric acid immersion 2h or concentrated hydrochloric acid heating immersion 30min, filtration, washing with water to neutral, drying. Acid washing can remove iron, aluminum, calcium, magnesium and other impurities on the surface, but can not remove the silanol base. Acid washing carrier is suitable for analyzing acidic samples.
3. The role of seamless tube pickling
The precision seamless steel tube surface for oil removal, rust removal, in order to prepare for the next process. In the production process, the pickling process is to q in addition to the surface oxide skin, after lubrication treatment (carbon steel - phosphorus saponification, stainless steel - butter lime, copper and aluminum tubes - coated with oil), with the old process - copper plating), and then pulling deep processing. Steel pipe if not pickled, the surface may have oxides and oil, phosphating liquid nuclear energy can not remove them, phosphating quality will be reduced.
