Reasons for Achieving Better Results When Oscillating Steel Tubes or Stirring the Solution During Pickling

When pickling steel tubes, the following experiences are commonly observed: Firstly, when the steel tubes are oscillated or when the pickling solution is agitated by steam heating, the pickling speed is much faster than when the steel tubes are left stationary in the pickling solution. For example, when pickling steel tubes in a reciprocally moving pickling basket with a motion speed of 30 times per minute, the pickling speed can be increased by about 70%; if hot air is used to stir the acid solution, the pickling speed of the steel tubes can be increased by about 20%. Secondly, as the surface of the steel tubes is scoured by the pickling solution, the attachment of hydrogen is reduced, leading to less hydrogen diffusing into the steel substrate. This decreases the occurrence of acid embrittlement and ensures the mechanical strength of the steel tubes. At the same time, due to the scouring effect, steam bubbles adhering to the surface of the steel tubes as well as other impurities, iron salts, and mill scale are peeled off, resulting in a clean steel tube surface. Thirdly, stirring the pickling solution can maintain a uniform composition, allowing for increased usage of the pickling solution.