CN112474822A - Cold continuous rolling production process for medium carbon steel - Google Patents

Abstract

The invention relates to a cold rolling production technology, and particularly discloses a medium carbon steel cold continuous rolling production process. The process takes a hot-rolled steel coil as a raw material, has a reduction rate of 40-58%, and is produced by a 5-frame 6-roller tandem cold continuous rolling mill, which specifically comprises the following steps: (1) rolling mill pass reduction: s1: 7-15%, S2: 9-14%, S3: 7-14%, S4: 7-14%, S5: 7-12%; (2) the rolling force of the frame: s1: 15000KN ~16000KN, S2: 15000KN ~16000KN, S3: 15000KN ~16000KN, S4: 16000KN ~17000KN, S5: 15000KN to 16000 KN; (3) tension between rolling mills: s1-2: 105-115 MPa, S2-3: 120-135 MPa, S3-4: 140-155 MPa, S4-5: 140 to 165 MPa. The process reasonably distributes the pass reduction rate, the rolling force and the rolling mill tension of the rolling mill, and ensures that the rolling process is stable and smooth and the product size meets the requirements.

Description

Cold continuous rolling production process for medium carbon steel

Technical Field

The invention relates to a cold rolling production technology, in particular to a medium carbon steel cold continuous rolling production process.

Background

In recent years, the industry of the Chinese measuring tool is rapidly developed and strengthened, and becomes a world-wide steel tape production nation, and the industrial scale occupies more than 60% of the world market. The demand of the steel for the measuring tape is greatly increased, and the research and development of the steel for the measuring tape are promoted to be enhanced by domestic iron and steel enterprises. At present, the single-frame reversible rolling is mainly adopted in domestic production, and the problems of low production efficiency, unstable quality and the like exist. Relevant reports about medium and high carbon steel cold continuous rolling are not seen through network retrieval.

The steel for the measuring tape is generally made of medium carbon steel, the strength is high due to the high carbon content, the rolling load of the domestic cold continuous rolling mill is basically close to the upper limit value of the mill, and the rolling mill is easy to alarm and stop or equipment is easy to damage due to the fluctuation in the rolling process. So that domestic fresh manufacturers adopt a cold continuous rolling unit for rolling. However, the cold continuous rolling mill set has the advantages of low cost, high efficiency and the like, and the cold continuous rolling mill set has high dimensional precision and high surface quality and just meets the high-quality requirement of an export tape product. In conclusion, a medium carbon steel cold continuous rolling production process is urgently needed.

Disclosure of Invention

The invention aims to provide a medium carbon steel cold continuous rolling production process which reasonably distributes pass reduction, rolling force and rolling mill tension of a rolling mill, and ensures that the rolling process is stable and smooth and the product size meets the requirements. The thickness of a finished product produced by the process is 1.0-2.0 mm, the width precision can reach +/-1 mm, and the thickness precision can reach +/-0.02 mm.

In order to achieve the purpose, the invention adopts the technical scheme that:

the medium carbon steel cold continuous rolling production process comprises the following components in percentage by mass: c: 0.42 to 0.70%, Si: 0.17 to 0.37%, Mn: 0.50-0.80%, P is less than or equal to 0.035%, S is less than or equal to 0.035%, Cr is less than or equal to 0.5%, Ni is less than or equal to 0.30%, and Cu is less than or equal to 0.30%.

Further, the process takes a hot-rolled steel coil as a raw material, the reduction rate is 40% -58%, and the hot-rolled steel coil is produced by a 5-frame 6-roller tandem cold continuous rolling mill, which specifically comprises the following steps:

(1) rolling mill pass reduction: s1: 7-15%, S2: 9-14%, S3: 7-14%, S4: 7-14%, S5: 7-12%;

(2) the rolling force of the frame: s1: 15000KN ~16000KN, S2: 15000KN ~16000KN, S3: 15000KN ~16000KN, S4: 16000KN ~17000KN, S5: 15000KN to 16000 KN;

(3) tension between rolling mills: s1-2: 105-115 MPa, S2-3: 120-135 MPa, S3-4: 140-155 MPa, S4-5: 140 to 165 MPa.

Furthermore, the thickness of a finished product produced by the process is 1.0-2.0 mm, the width precision is +/-2 mm, and the thickness precision is +/-0.02 mm.

Compared with the prior art, the invention has the beneficial effects that:

1. the production process reasonably distributes the pass reduction rate, the rolling force and the rolling mill tension of the rolling mill, adopts 5-rack 6-roller tandem cold continuous rolling mills to realize stable batch production process, has no strip breakage accident, and has the rolling force of the rolling mill fluctuating in a reasonable interval.

2. The process can produce finished products with the thickness of 1.0-2.0 mm, the width precision can reach +/-1 mm at most, the thickness precision can reach +/-0.02 mm at most, and the edge part has no edge cracking defect.

Drawings

FIG. 1 is a metallographic structure diagram of a medium carbon steel prepared in example 1 of the present invention after rolling;

fig. 2 is a schematic view of a medium carbon steel for a tape measure prepared in example 1 of the present invention.

Detailed Description

The technical solutions and effects of the present invention will be further described with reference to the drawings and specific embodiments, but the scope of the present invention is not limited thereto.

Example 1

The medium carbon steel for the measuring tape produced by the embodiment comprises the following components in percentage by mass: c: 0.45%, Si: 0.27%, Mn: 0.58%, P: 0.025%, S: 0.015%, Cr: 0.3%, Ni: 0.01%, Cu: 0.020%.

The hot rolled steel coil is used as a raw material, the reduction rate is 54%, and the parameters of the production process of the tandem cold continuous rolling mill with 5 frames and 6 rollers are as follows:

(1) the rolling reduction rates of S1-S5 frames are respectively 15%, 14%, 13% and 12%;

(2) S1-S5 rolling force setting of the stands are 15565KN, 15684KN, 15686KN, 16315KN and 15121 KN;

(3) the tensions among the S1-S5 frames are set to be 105MPa, 124MPa, 147MPa and 145 MPa.

The product produced in this example has a thickness of 1.0mm, a hot rolling raw material of 2.2mm, a reduction of 54%, a width precision of +2mm, and a thickness precision of-0.02 mm.

And (3) control strategy: because of the high strength of the medium carbon steel, the rolling reduction is basically and evenly distributed by each frame, and finally, the frame is used for improving the plate shape at the minimum.

The metallographic structure of the medium carbon steel rolled steel for the tape measure produced in this example is shown in fig. 1 and is a ferrite and pearlite structure, wherein the ferrite accounts for 55% and the pearlite structure accounts for 45%.

FIG. 2 is a schematic view of a medium carbon steel for a tape measure prepared according to this example, which has a smooth surface and no edge crack defect at the edge portion.

Example 2

The medium carbon steel for the measuring tape produced by the embodiment comprises the following components in percentage by mass: c: 0.52%, Si: 0.24%, Mn: 0.65%, P: 0.024%, S: 0.015%, Cr: 0.16%, Ni: 0.02%, Cu: 0.02 percent.

The hot rolled steel coil is used as a raw material, the reduction rate is 53%, and the parameters of the production process of the tandem cold continuous rolling mill with 5 frames and 6 rollers are as follows:

(1) the rolling reduction rates of S1-S5 frames are respectively 14%, 12% and 11%;

(2) S1-S5 rolling force settings of the stands are 15765KN, 15876KN, 15986KN, 16324KN and 15126 KN;

(3) the tension between the S1-S5 frames is set to be 108MPa, 125MPa, 150MPa and 150 MPa.

And (3) control strategy: because of the high strength of the medium carbon steel, the rolling reduction is basically and evenly distributed by each frame, and finally, the frame is used for improving the plate shape at the minimum.

The product produced in this example had a thickness of 1.20mm, a hot rolled stock of 2.5mm, a reduction of 53%, a width accuracy of +1mm, and a thickness accuracy of-0.02 mm.

Example 3

The medium carbon steel for the measuring tape produced by the embodiment comprises the following components in percentage by mass: c: 0.60%, Si: 0.25%, Mn: 0.70%, P: 0.022%, S: 0.017%, Cr: 0.18%, Ni: 0.02%, Cu: 0.01 percent.

The hot rolled steel coil is used as a raw material, the reduction rate is 47%, and the parameters of the production process of the tandem cold continuous rolling mill with 5 frames and 6 rollers are as follows:

(1) the rolling reduction rates of S1-S5 frames are respectively 13%, 10% and 9%;

(2) S1-S5 rack rolling force setting 15965KN, 15846KN, 15996KN, 16854KN and 15726 KN;

(3) the tension between the S1-S5 frames is set to be 108MPa, 128MPa, 150MPa and 153 MPa.

And (3) control strategy: because of the high strength of the medium carbon steel, the rolling reduction is basically and evenly distributed by each frame, and finally, the frame is used for improving the plate shape at the minimum.

The product produced in this example had a thickness of 1.60mm, a hot rolled stock of 3.0mm, a reduction of 47%, a width accuracy of-2 mm and a thickness accuracy of-0.02 mm.

Example 4

The medium carbon steel for the measuring tape produced by the embodiment comprises the following components in percentage by mass: c: 0.68%, Si: 0.18%, Mn: 0.72%, P: 0.023%, S: 0.018%, Cr: 0.20%, Ni: 0.02%, Cu: 0.02 percent.

The hot rolled steel coil is used as a raw material, the reduction rate is 45%, and the parameters of the production process of the tandem cold continuous rolling mill with 5 frames and 6 rollers are as follows:

(1) the rolling reduction rates of S1-S5 frames are respectively 14%, 13%, 10% and 10%;

(2) S1-S5 rack rolling force setting 15965KN, 15944KN, 15968KN, 16964KN and 15914 KN;

(3) the tensions among the S1-S5 frames are set to be 110MPa, 130MPa, 150MPa and 163 MPa.

And (3) control strategy: because of the high strength of the medium carbon steel, the rolling reduction is basically and evenly distributed by each frame, and finally, the frame is used for improving the plate shape at the minimum.

The product produced in this example had a thickness of 2.0mm, a hot rolling stock of 2.9mm, a reduction of 45%, a width accuracy of +2mm, and a thickness accuracy of +0.02 mm.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (3)

1. The medium carbon steel cold continuous rolling production process is characterized in that the medium carbon steel produced by the process comprises the following components in percentage by mass: c: 0.42 to 0.70%, Si: 0.17 to 0.37%, Mn: 0.50-0.80%, P is less than or equal to 0.035%, S is less than or equal to 0.035%, Cr is less than or equal to 0.5%, Ni is less than or equal to 0.30%, and Cu is less than or equal to 0.30%.

2. The medium carbon steel cold continuous rolling production process as claimed in claim 1, wherein the process is characterized in that a hot rolled steel coil is used as a raw material, the reduction rate is 40% -58%, and the process is produced by a 5-frame 6-roller tandem cold continuous rolling machine, and specifically comprises the following steps:

(1) rolling mill pass reduction: s1: 7-15%, S2: 9-14%, S3: 7-14%, S4: 7-14%, S5: 7-12%;

(2) the rolling force of the frame: s1: 15000KN ~16000KN, S2: 15000KN ~16000KN, S3: 15000KN ~16000KN, S4: 16000KN ~17000KN, S5: 15000KN to 16000 KN;

(3) tension between rolling mills: s1-2: 105-115 MPa, S2-3: 120-135 MPa, S3-4: 140-155 MPa, S4-5: 140 to 165 MPa.

3. The cold continuous rolling production process of medium carbon steel according to claim 1, wherein the thickness of a finished product produced by the process is 1.0-2.0 mm, the width precision is +/-2 mm, and the thickness precision is +/-0.02 mm.

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