Method for controlling pitting on surface of medium steel plate

Abstract

The invention discloses a method for controlling pitting on the surface of a medium steel plate, which prevents the surface of the medium steel plate from generating the pitting by controlling the components of a billet and adopting different heating and descaling processes according to different components, wherein the billet comprises the following chemical components in percentage by mass: 0.08 to 0.20 percent of C, 0.13 to 0.20 percent of Si, 0.90 to 1.60 percent of Mn, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, 0 to 0.04 percent of Nb, 0 to 0.018 percent of Ti, 0.02 to 0.05 percent of Alt and the balance of Fe and impurities; for a steel type containing a microalloy, a method for reducing Si content, heating the steel at a high temperature, descaling at the high temperature and fast cooling the steel after rolling the steel is adopted; and for a steel type containing no microalloy, a method for reducing Si content, heating the steel at a low temperature, descaling at the low temperature and fast cooling the steel after rolling the steel is adopted. The method of the invention can substantially clear off primary scales on the surface of the medium steel plate, thereby greatly reducing the occurrence of the pitting on the surface of the medium steel plate, and reducing the energy consumption and production cost and improving the production efficiency and the economic benefit of enterprises while guaranteeing the properties of the steel plate. The method is suitable to be popularized on a national scale.

Description

technical field [0001] The invention relates to a steel plate surface treatment method, specifically a method for controlling pitting on the surface of a medium-thick steel plate for preventing pitting on the surface of the steel plate during rolling. Background technique [0002] With the development of the steel industry, users have higher and higher requirements for steel plates. In addition to meeting the necessary mechanical performance indicators for steel plates, users have higher and higher requirements for the surface quality of steel plates. Steel plate pitting is a defect that often occurs on the surface of steel plates. It is mainly due to the fact that the iron oxide scale is not cleaned and pressed onto the surface of the steel plate during the heating or production process of the slab, and it falls off during the subsequent processing or transportation, forming pits, which makes the surface of the steel plate appear uneven and rough, also known as Pockmarked...

AI Technical Summary

Problems solved by technology

This method requires the use of special equipment to increase t