33.What are the advantages and disadvantages of steel pipe pickling in hydrochloric acid?

Advantages: 1) The pickling speed is fast; 2) The corrosion of the base metal of the steel pipe is less, thus saving steel consumption; 3) The diffusion of hydrogen into the base metal of the steel pipe is less, the influence of pickling bubbles and the mechanical strength of the steel pipe is less.
4) The surface of steel pipe is relatively clean after pickling; 5) The iron salt adhered on the surface of steel pipe is easy to be washed away; 6) Pickling can be carried out at room temperature or low temperature, which improves the environmental conditions to a certain extent.
Disadvantages: 1) High cost of pickling; 2) Waste pickling solution is difficult to recycle; 3) Harmful hydrogen chloride gas escapes during pickling; 4) When the pickling solution concentration decreases, temperature increase cannot maintain pickling capacity, resulting in high acid consumption; 5) Hydrochloric acid must be stored in porcelain or glass containers, making storage and transportation inconvenient.