1. The influence of hydrochloric acid concentration and temperature
In the hydrochloric acid solution, the pickling speed increases with the increase of acid concentration and temperature, but because hydrochloric acid is volatile, the acid concentration and temperature are restricted.
2. The influence of FeCl2 in acid solution
The shortest pickling time is obtained when the FeCl2 content in the acid solution is optimal; the optimal FeCl2 content is lower than about 4-8% of its saturation value in this state; when FeCl2 is close to the saturation value, the acid The washing time is the longest.
During the entire period of hydrochloric acid pickling, although the content of hydrochloric acid is decreasing, FeCl2 increases correspondingly at the same time. These two influencing factors cancel each other out within a certain pickling time, so the pickling speed during this period of time only changes slightly.
The pickling speed is to make the strip steel in the acid solution for a predetermined time, and pass the acid solution too fast, resulting in under-pickling.
The degree of mechanical dephosphorization is sufficient to accelerate the pickling speed.