Hot-rolling steel plate cleaning agent

Abstract

The invention publishes a kind of hot rolled steel plate and metal strip cleaning agent to clean black oxide film and rust on them. The cleaning agent is composed by 15-28% sulphuric acid (proportion is 1.84), 13-20% chloride ion and 31-71% water, the total acidity is 40-60 points and the work temperature is 20-80 degree. It can take place of thick hydrochloric acid to do cleaning. The chloride ion can be gotten from lithium chloride, sodium chloride, hydrochloric and so on. the noxious gas the cleaning agent, such as hydrogen chloride, can be reduced by 80%. So it can reduce the pollution and can prolong the dish life of arrangement.

Description

technical field [0001] The invention relates to a cleaning agent for hot-rolled steel plates or steel strips, which is used for quickly cleaning black oxide film and rust on the surface of hot-rolled steel plates or steel strips. Background technique [0002] During the rolling process of hot-rolled steel sheets or strips, due to high temperature, a layer of black oxide Fe will be formed on the surface. 3 o 4 ; Some rust will be generated during transportation and storage. Usually the cold-rolled sheet or strip is made from the cooled hot-rolled steel sheet or strip. Before cold-rolling, the black oxide film and rust on the surface must be cleaned. Due to the large production batch and fast line speed, the cleaning process is only allowed to be completed within 1 to 2 minutes. At present, the widely used method is to wash with 28-32% concentrated hydrochloric acid at a temperature of 70-80°C, which can meet the production requirements. The main disadvantages of this meth...

AI Technical Summary

Problems solved by technology

The main disadvantages of this method are: a large amount of hydrogen chloride is volatilized due to cleaning at a temperature of 70-80 ° C, the use efficiency of concentrated hydrochloric acid is low, the cost is high, and it causes serious pollution to the environment and corrosion of equipment; if sulfuric acid is used for cleaning, Although there is no volatilization of hydrogen chloride, the cleaning temperature must be ≥ 90°C. Hydrogen is easy to permeate, which will increase the surface hardness and brittleness of the steel plate or steel strip, which is not good for rolling and rolling equipment. At the same time, the surface of the steel plate or steel strip after cleaning Dark gray, affecting appearance and quality

[0007] However, the formulas of the above three patents are not exactly the same as those of the present invention. At present, there is no bibliographical report identical with the hot-rolled steel plate or steel strip cleaning agent of the present invention.