Notes of carbon steel pipe pickling

Pickling is oxide washed with hydrofluoric acid + nitric acid solution on steel surface after heated treatment. which used in the solution composition and ratio values​​: HF (3-8%), of HNO3 (10-15%), H2O (remaining amount), the processing solution temperature of 40-60 ℃. Notes of carbon stee pipe pickling process: The first point is the acceptance of incoming materials listed, specifications, quantity and straightening cutting quality, acceptance of failure to suspend pickling and timely notice of the quality inspection department or workshop. The second point is ready to work. First, in accordance with the ratio of the value of shop floor control add acid, add acid should be evenly distributed in the pickling tank, rather than add in a certain part of the acid tank; then control the size of the volume of steam to control the temperature of the acid the general control of the temperature of the acid to slightly steaming (about 60 degrees) should not control the temperature is too high and even the feeling of acid boiling; the rest is to organize the process of site steel pipe card, the distinction between different frame of steel because of the differences of steel the pickling time. The third point for the pickling process control, and also the most important step. Vary in the products, mild steel pipe and finished steel pickling and degreasing. The fourth point inspection after pickling. Finished pickling steel pipe inspection focused primarily on steel pipes inside and outside surface of the oxide cleanliness, especially the cleanliness of the bore, the best yarn Brad over inspection, sampling should be not less than 10%. Followed by inspection of the steel pipe surface acid blotting and steel color case, the test failed to re-pickling; away oil structural steel pipe surface should be no significant oil pollution, with particular attention to the steel pipe at both ends should be no residual acid outflow.