A process for continuous skin pass pickling of high carbon steel

Abstract

The application provides a high-carbon steel continuous skin-pass pickling process method, which adopts the mode of alternating production of high-carbon steel and low-carbon steel, is based on the endless rolling process, and optimizes the entry loop control; meanwhile, the process method adopts the scale breaker process and the welding seam passing mode; the parameters of the tension and straightening machine are optimized in the process method; the surface darkening of high-carbon steel in the shallow grass turbulent pickling is improved, and the pickling and rinsing process are demonstrated through experiments. The high-carbon steel continuous skin-pass pickling process method is based on the pickling process of cold-rolled acid-skin low-carbon steel, and the production of high-carbon steel in the acid-skin line is realized by optimizing various process parameters, so that the requirements of users on the pickling products of high-carbon steel are met; the process method is based on the stable operation of the continuous shallow groove turbulent pickling unit for high-carbon steel, and the surface and shape of the finished product meet the requirements of users on the product quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pickling process of high carbon steel, and particularly relates to a process method for continuous skin pass pickling of high carbon steel. BACKGROUND

[0002] In order to broaden product structure and adapt to market situation, high carbon steel varieties are developed by hot rolling, and at present, there are 45, 50, 40Mn, 45Mn, 50Mn and other steel grades. SUMMARY

[0003] In view of the deficiencies in the prior art, the present application provides a process method for continuous skin pass pickling of high carbon steel, which realizes stable production of high carbon steel in a continuous pickling unit, improves the quality of finished products, and meets the requirements of users for pickling surface and shape quality of high carbon steel.

[0004] In order to achieve the above-mentioned purpose, the present application provides a process method for continuous skin pass pickling of high carbon steel, which adopts an alternating production mode of high carbon steel and low carbon steel, and is based on a endless rolling process and optimized entry loop control.

[0005] In the alternating production process of high carbon steel and low carbon steel, the high carbon steel and the low carbon steel are welded, and the thickness difference of the front and rear strips is ≤ 10% of the strip thickness, and the thickness difference of the front and rear strips is ≤ 0.5 mm.

[0006] In the process of optimizing the entry loop control based on the endless rolling process, the loop amount is ≤ 75%, the tension is 55 KN, and the loop filling speed is ≤ 120 mpm.

[0007] In the process of adopting the scale breaker, the elongation E is 0.6%, the staggered degree of the bending unit is 45 mm, and the straightening unit is 48 mm.

[0008] In the process of passing through the weld seam, a short opening mode is adopted, the passing speed through the weld seam is 60 mpm, and the weld seam is accelerated after passing through the tension leveler.

[0009] In the process of optimizing the tension leveler parameters, the elongation of low carbon steel is set to 0.4%, the elongation of high carbon steel is set to 0.2%, the bending unit is 45 mm, the straightening unit is 48 mm, and the outlet tension is 200-250 KN.

[0010] In the process of improving the dark surface of high carbon steel in shallow turbulence pickling, through experimental demonstration, the temperature of 1#-5# acid tank is set to 75℃, 74℃, 73℃, 73℃ and 73℃, the pickling inhibitor is used according to 0.8‰; the rinsing water temperature is 45-50℃, and the rinsing inhibitor is used according to 0.5‰.

[0011] Compared with the prior art, the advantages and positive effects of the present application are that: the process method for continuous skin pass pickling of high carbon steel provided by the present application is based on the pickling process of cold-rolled low carbon steel, and by optimizing various process parameters, the production of high carbon steel in the skin pass line is realized, and the requirements of users for pickled high carbon steel products are met; the process method is based on the stable operation of the continuous shallow tank turbulence pickling unit for high carbon steel, and the surface and shape of the finished product meet the quality requirements of users. DETAILED DESCRIPTION

[0012] The present application will now be specifically described by way of example. However, it should be understood that the structures and features in one embodiment can also be beneficially incorporated into other embodiments without further elaboration.

[0013] An embodiment of the present application provides a process method for continuous skin pass pickling of high carbon steel, which adopts an alternating production mode of high carbon steel and low carbon steel, and is based on a seamless rolling process and optimized entry loop control; at the same time, the process method adopts a scale breaker process and a welding seam passing mode; the parameters of the tension leveler are optimized in the process method; and the process method improves the dark surface of high carbon steel in shallow turbulence pickling, and the pickling and rinsing processes are carried out through experimental demonstration.

[0014] In the alternating production process of high carbon steel and low carbon steel in the present embodiment, the high carbon steel and the low carbon steel are welded, the thickness difference of the front and rear strips is ≯10% of the strip thickness, and the thickness difference of the front and rear strips is ≯0.5mm, the MIBACH laser welder based on the wire filling function is used in the present embodiment, the welding code is selected as "9" to adopt the wire filling welding mode, the welding parameters are optimized, and the welding stability meets the operation requirements of the unit. The welding parameters are shown in the following table:

[0015]

[0016] In the present embodiment, based on the seamless rolling process, the shape difference of high carbon steel, the entry loop deviation and scratches are optimized, and the specific parameter settings are as follows: loop amount ≤75%, tension 55KN, loop filling speed ≤120mpm (low carbon steel: loop amount ≤85%, tension 45KN, loop filling speed ≤500mpm).

[0017] In order to improve the shape of high carbon steel plate and improve the pickling effect, the scale breaker process is adopted in the embodiment: elongation E=0.6%, staggered degree bending unit 45mm, straightening unit 48mm; the over-welding seam mode is adopted in the embodiment: short opening mode, over-welding seam speed=60mpm, the weld is accelerated after passing through the stretch leveler (elongation of low carbon steel 0.8%, staggered degree bending unit 50mm, straightening unit 55mm; over-welding seam mode: normal passing).

[0018] Further, in the process of optimizing the parameters of the stretch leveler in the embodiment, the elongation of low carbon steel is set to 0.4%, the elongation of high carbon steel is set to 0.2%, the bending unit is 45mm, the straightening unit is 48mm, and the outlet tension is 200-250KN.

[0019] In the embodiment, the surface of high carbon steel is improved by the process of pickling and rinsing: 1#-5# acid tank temperature is set to 75℃, 74℃, 73℃, 73℃, 73℃, the pickling inhibitor is used according to 0.8‰; the rinsing water temperature is 45-50℃, and the rinsing inhibitor is used according to 0.5‰ (the 1#-5# acid tank temperature of low carbon steel is set to 77℃, 75℃, 74℃, 74℃, 74℃, the pickling inhibitor is used according to 0.5‰; the rinsing water temperature is 40-60℃, and the rinsing inhibitor is used according to 0.5‰), which meets the surface of high carbon steel and does not affect the pickling surface of low carbon steel.

[0020] Of course, the present application can have other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should belong to the protection scope of the claims attached to the present application.

Claims

1. A process for continuous skin pass pickling of high carbon steel characterized by: The process method adopts high carbon steel and low carbon steel alternately, and is based on the process of headless rolling, and the entry loop control is optimized; meanwhile, the process method adopts the process of scale breaker and the method of passing through the welding seam; The process method optimizes the parameters of the straightening mill; the process method improves the dark surface of high carbon steel in shallow grass turbulence pickling, and through experimental demonstration, the pickling and rinsing process is carried out; in the process of high carbon steel and low carbon steel alternately, high carbon steel and low carbon steel are welded, the thickness difference of the front and rear strip steel is ≯10% of the thickness of the strip steel, and the thickness difference of the front and rear strip steel is ≯0.5mm; based on the process of headless rolling, the process of optimizing the entry loop control: loop amount ≤75%, tension 55KN, filling loop speed ≤120mpm; in the process of adopting the process of scale breaker, the elongation E=0.6%, the staggered degree bending unit 45mm, the straightening unit 48mm; in the process of passing through the welding seam, the short opening method is adopted, the passing through the welding seam speed=60mpm, the welding seam is accelerated after passing through the straightening mill; in the process of optimizing the parameters of the straightening mill, the elongation of low carbon steel is set to 0.4%, the elongation of high carbon steel is set to 0.2%, the bending unit is 45mm, the straightening unit is 48mm, and the outlet tension is 200-250KN.

2. The process for continuous skin pass pickling of high carbon steel as claimed in claim 1 wherein: In the process of improving the dark surface of high carbon steel in shallow grass turbulence pickling, through experimental demonstration, the pickling and rinsing process is carried out, the temperature of 1#-5# acid tank is set to 75℃, 74℃, 73℃, 73℃, 73℃, the pickling inhibitor is used according to 0.8‰; the rinsing water temperature is 45-50℃, and the rinsing inhibitor is used according to 0.5‰.

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