Controlling method for scales on surface of low-carbon cold heading steel hot-rolled wire rods

Abstract

A controlling method for scales on surface of low-carbon cold heading steel hot-rolled wire rods belongs to the field of steel rolling. The method includes steps of precision rolling temperature control, spinning temperature control, and phase-change forepart cooling speed control for an air cooling line. The technical parameters of control includes: controlling the temperature of an entrance of a precision rolling mill in a range of from 900 DEG C to 950 DEG C; controlling the temperature rise in the precision rolling process in a range of from 80 DEG C to 100 DEG C; controlling the spinning temperature in a range of from 880 DEG C to 920 DEG C; adjusting a heat preservation hood of the air cooling line and blower level and controlling the cooling speed of the phase-change forepart of the spun rods in a range of from 2 DEG C per second to 5 DEG C per second; controlling the hood entry temperature in a range of from 760 DEG C to 700 DEG C; and advancing the phase-change area and controlling the time when the wire rods stay in a high-temperature oxidation section in a range of from 60 seconds to 100 seconds. By the method, the thickness of the scales on the surface of the hot-rolled wire rods is controlled evidently in the production of low-carbon cold heading steel SWRCH22A wire rods, mechanical dephosphorization capability is enhanced remarkably while falling during transportation is avoided, and broken rate in spinning and wastage of dies during drawing are reduced.

Description

technical field [0001] The invention belongs to the field of steel rolling, and in particular provides a method for controlling the oxide scale on the surface of low-carbon cold heading steel hot-rolled wire rods, which is applied to high-speed wire factories to produce cold-drawn low-carbon cold-heading steel hot-rolled wire rods. Low-carbon cold heading steel hot-rolled wire rod surface oxide scale control technology. Background technique [0002] Low-carbon cold heading steel wire rod is mainly used to make standard parts, and users need to use mechanical peeling method to remove surface oxide scale before cold drawing. Because the iron oxide scale is hard, brittle and difficult to deform, the iron oxide scale cannot be removed cleanly. During the subsequent cold drawing process, the surface of the steel wire will be damaged, resulting in broken wires during subsequent processing, and it will aggravate the wear of the die, thus affecting the life of the wire drawing die a...

AI Technical Summary

Problems solved by technology

The oxide scale is too thin, and it is difficult to remove the thinner oxide scale by mechanical peeling

If the iron oxide scale is too thick, the hot-rolled wire rod is easy to fall off during handling and transportation, and it is easy to scratch the surface of the wire rod, causing wire breakage in the subsequent drawing process

[0003] Since low-carbon cold heading steel generally adopts slow cooling process after rolling, it is difficult to obtain iron oxide scale with good descaling performance by adopting traditional production process.

There is no report on scale thickness control of low carbon cold heading steel

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