Pickling method of Cr-containing hot-rolled pickled plate

Abstract

The invention discloses a pickling method of a Cr-containing hot-rolled pickled plate, which comprises the following steps: adding a corrosion inhibitor to an acid solution with free acid concentration of 80-110 g / L to obtain a pickling solution, wherein the corrosion inhibitor accounts for 0.05-0.10% by weight of the pickling solution; heating the pickling solution to 60-80 DEG C; and then pickling the Cr-containing hot-rolled pickled plate with the heated pickling solution for 25-50 s. The pickling method has the advantages of low difficulty in process control, strong operability, simple method, low cost and the like; the Cr-containing hot-rolled pickled plate with good surface color is obtained by controlling the pickling solution concentration, pickling solution temperature, pickling process speed and other parameters of the pickling process, so that the quality problem of surface blackening of the pickled plate is effectively solved and the metal loss during pickling is reduced.

Description

technical field [0001] The invention relates to a pickling method, in particular to a pickling method for a Cr-containing hot-rolled pickling plate. Background technique [0002] The hot-rolled pickled plate is made of high-quality hot-rolled thin plate, which is formed after the pickling unit removes the oxide layer, trims the edge, and finishes. The main processing procedures include laser welding, turbulent pickling, online leveling, cutting Edge, online oiling, etc., the surface quality and use requirements of hot-rolled pickled sheets are between hot-rolled sheets and cold-rolled sheets, and they are ideal substitutes for some hot-rolled sheets and cold-rolled sheets. [0003] Compared with ordinary hot-rolled sheets, hot-rolled pickled sheets need to remove their surface oxide scales to improve the surface quality of steel, which is convenient for welding, oiling and painting. The main surface quality problems of hot-rolled pickled plates are over-pickling (the surfac...

AI Technical Summary

Problems solved by technology

[0010] The invention patent with the publication number CN102400156A "A Method for Pickling Hot-Rolled Coils" discloses a pickling method, in which the pickling time is not limited. Obviously, the pickling time is too long or too short to obtain the described Pickling effect; secondly, the pickling method only shows that the concentration of the prepared hydrochloric acid is 15%-19%, but in industrial production, the effective concentration of hydrochloric acid (that is, the concentration of free acid) reacts with the oxide scale on the surface of the steel plate. Will quickly reduce, will lead to under-pickling (iron oxide scale can not be washed), so this pickling method is only suitable for small batch experimental research in the laboratory, not suitable for large-scale industrial production; finally, this pickling method is only suitable for general Ordinary hot-rolled sheets are effective, but for Cr-containing hot-rolled sheets, this pickling process cannot meet the requirements

[0011] The surface of the normal pickling plate is white, but the surface of the Cr-containing hot-rolled plate has a layer of residue attached to the surface of the steel base after pickling, making the surface of the steel plate appear gray-black, affecting the appearance and user use