Why is it beneficial to oscillate steel pipes or create solution flow during pickling?

During the pickling of steel pipes, it is generally observed that: Firstly, when the steel pipes are oscillated or the pickling solution is agitated by steam heating, the pickling rate is significantly faster than when the steel pipes are left stationary in the pickling solution. For example, oscillating steel pipes at a speed of 30 times per minute in a pickling basket that moves reciprocally can increase the pickling rate by approximately 70%. Similarly, stirring the acid solution with hot air can enhance the pickling rate of steel pipes by about 20%. Secondly, the冲刷 action of the pickling solution on the steel pipe surface reduces the amount of hydrogen adhering to it, which in turn decreases the diffusion of hydrogen into the steel substrate, mitigating acid embrittlement and ensuring the mechanical strength of the steel pipes. Additionally, the冲刷 effect helps detach steam bubbles, impurities, iron salts, iron oxide scales, and other adherents from the steel pipe surface, resulting in a cleaner surface. Thirdly, agitation of the pickling solution maintains a uniform composition, thereby increasing the number of times the pickling solution can be used.