What is the pickling process of precision seamless steel pipe?

The main methods are impregnation acid washing, spray acid washing and acid cream derusting. Generally, dipping acid washing method is used, and spray method can be used in mass production. Steel parts are generally pickled in 10% - 20% (volume) sulfuric acid solution at 40 ℃. When the iron content in sulfuric acid solution exceeds 215g / L, the iron content in sulfuric acid solution should exceed 215 g / L. Under normal temperature, pickling steel with 20% - 80% (volume) hydrochloric acid solution is not easy to occur over corrosion and hydrogen embrittlement.

Due to the great corrosion effect of acid on metal, it is necessary to add corrosion inhibitor. After cleaning, the metal surface becomes silver white and passivates the surface to improve the corrosion resistance of stainless steel. In order to eliminate the adsorption on the surface of diatomite carrier and reduce the tailing of chromatographic peak, the carrier should be acid washed or alkaline washed before use.

Pickling is to soak the carrier with 6mol / L hydrochloric acid for 2h or heated with concentrated hydrochloric acid for 30min, filter, wash with water to neutral, and dry. Pickling can remove iron, aluminum, calcium, magnesium and other impurities on the surface, but can not remove the silanol group. The acid washing carrier is suitable for the analysis of acid samples.