A control method for reducing head and tail shearing amount of a non-quenched and tempered steel wire rod

Abstract

The application discloses a control method for reducing head and tail shearing amount of non-quenched and tempered steel wire rod, and the rolled material of the non-quenched and tempered steel wire rod is controlled and cooled to adjust a structure state through water cooling of cooling water of a 1# cooling water tank, a 2# cooling water tank and a 3# cooling water tank and Stelmor air cooling, and the method comprises the following steps: 1) the 1# cooling water tank is set in a BOX mode, and the wire rod is water-penetrated throughout; 2) the 2# cooling water tank is set, the head is not water-penetrated for 1m-3m, and the tail is not water-penetrated for 0-3m; 3) the 3# cooling water tank is set, the head is not water-penetrated for 1m-5m, and the tail is not water-penetrated for 1m-5m; and 4) air-cooling wire roller way speed is set, and the falling sections of 10th, 12th, 14th and 16th sections are set to be 70%-90%, and the rest sections are set to be 100%. The application improves the head and tail quality stability, reduces the head and tail shearing amount, solves the problem of large head and tail shearing amount, and improves the quality control level of the non-quenched and tempered steel.

Description

Technical Field

[0001] This invention relates to steel manufacturing, and more particularly to a method for controlling the amount of head and tail shearing in non-quenched and tempered steel wire. Background Technology

[0002] To meet the requirement of direct processing in subsequent stages without tempering, non-quenched and tempered steel wire rods significantly reduce manufacturing costs and time. This is mainly achieved through the addition of alloying elements and control of the microstructure during rolling. Hot-rolled non-quenched and tempered steel must possess good mechanical properties and be free of brittle structures such as martensite. Simultaneously, to ensure sufficient strength after processing, the grain size must be ≥6. The characteristics of high-speed wire rod rolling, such as the lack of water purging at the beginning and end of the cooling tank and excessively rapid cooling rates at the beginning and end of the air-cooled line, result in insufficient mechanical properties at the beginning and end, and excessive shearing at both ends.

[0003] Therefore, it is necessary to develop targeted control methods to reduce the amount of head and tail shearing in non-quenched and tempered steel wire, thus solving the problem of excessive head and tail shearing in non-quenched and tempered steel wire. Summary of the Invention

[0004] Purpose of the invention: To address the shortcomings and defects of existing technologies, this invention provides a method for controlling the amount of head and tail shearing in non-quenched and tempered steel wire rod, improving the quality stability of the head and tail, reducing the amount of head and tail shearing, solving the problem of large head and tail shearing amounts, and simultaneously improving the quality control level of non-quenched and tempered steel.

[0005] Technical Solution: The present invention provides a method for controlling the amount of head and tail shearing in non-quenched and tempered steel wire rod. The non-quenched and tempered steel wire rod is cooled by water cooling in cooling water tanks 1, 2, and 3, and by controlled cooling in a Steyrmo air-cooled line to adjust its microstructure. The method includes the following steps:

[0006] 1) Cooling water tank #1 is set up in BOX mode, with the entire cable running through water;

[0007] 2) The No. 2 cooling water tank is designed so that the head is not submerged by water for 1m-3m and the tail is not submerged by water for 0-3m.

[0008] 3) The No. 3 cooling water tank is designed so that the head is not submerged in water for 1m-5m and the tail is not submerged in water for 1m-5m.

[0009] 4) Speed ​​increase settings for the air-cooled roller conveyor: 70%-90% for drop sections 10, 12, 14, and 16, and 100% for the remaining sections.

[0010] In step 1), the uniformity of the sprue is ensured by sprue water flow throughout the entire process.

[0011] In step 2), the head is not submerged in water for 1 meter, and the tail is not submerged in water for 0 meters.

[0012] In step 3), the head and tail are not submerged in water for 2m.

[0013] In step 4), the speed increase setting of the air-cooled roller conveyor is set to 80% for the 10th, 12th, 14th, and 16th drop sections, and 100% for the remaining sections.

[0014] In step 4), the roller speed is reduced by the drop section to achieve accumulation at the head and tail, increase the accumulation thickness, reduce the cooling rate, and avoid the formation of martensite at the head and tail.

[0015] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: It improves the quality stability of the head and tail sections, reduces the amount of shearing at both ends, solves the problem of large shearing amounts at the head and tail, and simultaneously improves the quality control level of non-quenched and tempered steel. After stable production of non-quenched and tempered steel wire rod, the overall quality of the wire rod is stable, user feedback is positive, achieving the expected results and meeting market development trends and cutting-edge technology requirements. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0017] The present invention discloses a method for controlling the reduction of head and tail shearing in non-quenched and tempered steel wire rod. The non-quenched and tempered steel wire rod is cooled by water cooling in cooling water tanks #1, #2, and #3, and then by controlled cooling in a Steyrmo air-cooled line to adjust its microstructure. The method includes the following steps:

[0018] 1) Cooling water tank #1 is set up in BOX mode, with the entire cable running through water;

[0019] 2) The No. 2 cooling water tank is designed so that the head is not submerged by water for 1m-3m and the tail is not submerged by water for 0-3m.

[0020] 3) The No. 3 cooling water tank is designed so that the head is not submerged in water for 1m-5m and the tail is not submerged in water for 1m-5m.

[0021] 4) Speed ​​increase settings for the air-cooled roller conveyor: 70%-90% for drop sections 10, 12, 14, and 16, and 100% for the remaining sections.

[0022] Example:

[0023] We supply φ14mm non-quenched and tempered steel wire rod for automotive manufacturers. The rolled material undergoes water cooling in cooling tanks #1, #2, and #3, followed by controlled cooling in a Steyrmo air-cooled line to adjust its microstructure and obtain the finished product meeting the technical requirements. Specific requirements are as follows:

[0024] 1) Cooling water tank #1 is set up in BOX mode, with the entire cable running through water. Full water flow ensures uniform flow of the cable.

[0025] 2) The No. 2 cooling water tank is set so that the head is not submerged by water for 1m and the tail is not submerged by water for 0m.

[0026] 3) The cooling water tank #3 is set with a 2m unwatered section at both the head and tail. This ensures the wire rod can be rolled normally with the minimum unwatered lengths at both ends, reducing the risk of coarse microstructure caused by high temperatures at the unwatered sections.

[0027] 4) The speed increase setting of the air-cooled line roller conveyor is set to 80% for the drop sections (sections 10, 12, 14, and 16) and 100% for the remaining sections. By reducing the roller conveyor speed in the drop sections, the head and tail sections are stacked, increasing the stack thickness, reducing the cooling rate, and avoiding the formation of supercooled structures such as martensite at the head and tail.

[0028] The φ14mm non-quenched and tempered steel wire produced using the above control method had its head and tail shearing reduced from 10 turns to 4 turns, resulting in a 1% reduction in yield loss. Metallographic analysis of samples was performed, and the results are shown in the table below:

[0029]

[0030] After production, the amount of shearing was reduced, and the finished product test results all met the technical requirements. This batch of steel was sent to the user for the manufacture of automotive ball joints, and its performance was good, meeting the user's requirements.

Claims

1. A method of controlling the reduction of head and tail shear in a non-quenched steel wire rod, characterized by: The non-quenched steel wire rod is cooled by cooling water of 1# cooling water tank, 2# cooling water tank and 3# cooling water tank, and the structure state is adjusted by air cooling line control cooling, including the following steps: 1) 1# cooling water tank is set, BOX mode, wire rod is fully water-cooled; 2) 2# cooling water tank is set, 1m-3m of head part is not water-cooled, 0-3m of tail part is not water-cooled; 3) 3# cooling water tank is set, 1m-5m of head part is not water-cooled, 1m-5m of tail part is not water-cooled; 4) air cooling line roller way speed-up setting, 10 sections, 12 sections, 14 sections, 16 sections drop sections are set to 70%-90%, and the rest sections are set to 100%.

2. The method of claim 1, wherein the non-quenched and tempered steel wire rod is characterized in that: The step 1) ensures uniformity of the wire rod by full water cooling.

3. The method of claim 1, wherein the non-quenched and tempered steel wire rod is characterized by: In the step 2), 1m of head part is not water-cooled, and 0 of tail part is not water-cooled.

4. The method of claim 1, wherein the non-quenched and tempered steel wire rod is characterized by: In the step 3), 2m of head part is not water-cooled, and 2m of tail part is not water-cooled.

5. The method of claim 1, wherein the non-quenched and tempered steel wire rod is characterized by: In the step 4), air cooling line roller way speed-up setting, 10 sections, 12 sections, 14 sections, 16 sections drop sections are set to 80%, and the rest sections are set to 100%.

6. The method of claim 5, wherein the non-quenched and tempered steel wire rod is characterized in that: The step 4) reduces roller way speed by drop sections, realizes head and tail part accumulation, increases accumulation thickness, reduces cooling speed, and avoids martensite in head and tail.

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