Acid-washing method for common carbon steel/semi-process electrical steel with thickness of 3.0-6.0mm

Abstract

The invention discloses an acid-washing method for common carbon steel / semi-process electrical steel with thickness of 3.0-6.0mm. The acid-washing method comprises the following steps of: adding acid-washing accelerator into a hydrochloric acid acid-washing solution when the concentration of free acid in the hydrochloric acid acid-washing solution is reduced from 180-200g / L to 110-120g / L and the concentration of Fe<2+> is increased to 50-70g / L; controlling a volume ratio of acid-washing accelerator to hydrochloric acid acid-washing solution to be (0.4-0.6):100; and after acid-washing for 40-70 seconds under the temperature of 80-85 DEG C, rinsing with hot water. The acid-washing accelerator is composed of surface active agent, organic complexing chelant, corrosion inhibitor, reducing agent and stabilizing agent, wherein the concentration of the surface active agent is 5-10g / L; the concentration of the organic complexing chelant is 20-40g / L; the concentration of the corrosion inhibitor is 10-20g / L; the concentration of the reducing agent is 20-30g / L; and the concentration of the stabilizing agent is 10-15g / L. The surface scale of the common carbon steel / semi-process electrical steel is eliminated by using the hydrochloric acid acid-washing solution mixed with the acid-washing accelerator, the acid-washing speed is increased by above 35% and the surface quality is similar to the effect by using the imported acid-washing accelerator.

Description

technical field [0001] The invention relates to a pickling method for steel plates, in particular to a pickling method for 3.0-6.0mm common carbon steel / semi-process electrical steel. Background technique [0002] During hot rolling of thick-gauge ordinary carbon steel / semi-process electrical steel, due to the high surface temperature of the strip steel, Fe from the outside to the inside will be formed on the surface. 2 o 3 , Fe 3 o 4 , FeO and Fe 2 SiO 4 A thick layer of iron oxide scale, etc., which must be removed before subsequent cold rolling. Since this iron oxide layer is formed at high temperature, the surface layer of iron oxide scale is very dense, and it is difficult for pickling solution to react with the surface layer of iron oxide scale, but the inner layer of iron oxide scale is prone to react. In addition, due to the segregation of elements in the smelting process and the hot rolling process can cause the enrichment of elements such as Cu, Ni, As, etc.,...

AI Technical Summary

Problems solved by technology

[0005] It can be seen that they only dealt with some problems from one angle. The pickling or treatment process of the surface oxide scale of thick gauge (thickness ≥ 3.0mm) ordinary carbon steel / semi-process electrical steel has not yet been reported.