CN114774775A

CN114774775A - High-strength long-life steel wire for card clothing and manufacturing method thereof

Info

Publication number: CN114774775A
Application number: CN202210291134.8A
Authority: CN
Inventors: 白云; 李炫均; 陈海燕; 刘海; 孙逸澄; 张�林
Original assignee: Jiangyin Xingcheng Alloy Material Co ltd; Jiangyin Xingcheng Special Steel Works Co Ltd
Current assignee: Jiangyin Xingcheng Alloy Material Co ltd; Jiangyin Xingcheng Special Steel Works Co Ltd
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-07-22
Anticipated expiration: 2042-03-23
Also published as: CN114774775B

Abstract

The invention relates to a high-strength long-life steel wire for card clothing and a manufacturing method thereof, wherein the wire comprises the following chemical components in percentage by mass: c: 0.85% -0.95%, Mn: 0.45% -0.60%, Si: 0.15% -0.35%, Nb: 0.010% -0.040%, V: 0.10 to 0.50 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.015 percent of S, less than or equal to 0.06 percent of Cr, less than or equal to 0.05 percent of Ni, less than or equal to 0.05 percent of Cu, and the balance of Fe and inevitable impurities. By reasonable component design and a stelmor air cooling line air cooling process for subsequent high-speed wire rolling, the finished product of the net-shaped carbide is inhibited and the evenness of the whole strip is improved by increasing the cooling rate and the contact area of the wire rod; not only improves the quality of finished products, but also reduces the production cost.

Description

High-strength long-life steel wire for card clothing and manufacturing method thereof

Technical Field

The invention belongs to the fields of steel technology and heat treatment, and particularly relates to a high-strength long-life steel wire for card clothing and a manufacturing method thereof.

Background

In recent years, the technical upgrading and equipment transformation of the textile industry in China are obviously accelerated, and high yield and high speed of a manufacturing factory are required to be matched with high-end metal card clothing with high wear resistance so as to play the high efficiency of the card clothing. The global financial crisis causes the profit shortage of domestic textile enterprises, the price of the metal card clothing is inevitably related to the cost reduction, and the price of the imported high-end metal card clothing in the market is more than 3 times that of the domestic product, so that the manufacturing industry of the high-end products has a large profit margin. The localization of high end carding wire clothing is a real choice and challenge for both textile and wire clothing manufacturers. On the basis of detecting, comparing and analyzing a large amount of imported card clothing, the card clothing made in China needs to be developed towards high wear resistance, long service life and low cost.

In order to reduce the negative effect of the increase of the carbon content and further improve the toughness of the material, the preferable composition design and process route scheme are particularly important. The addition of trace Nb and V in the high-carbon steel plays an active role in inhibiting the network cementite of the material, improving the plasticity and the uniformity of the structure of the material and realizing the improvement of the obdurability.

The application number CN202011606668.2 is a high elasticity high nickel alloy card clothing steel wire and its preparation method, the high elasticity card clothing steel realizes high elasticity through component adjustment and rare earth element addition, the invention adopts the adjustment of components, and high strength requirement can be realized without adding rare earth element.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-strength long-life steel wire rod for card clothing and a manufacturing method thereof aiming at the prior art, the steel wire rod for the card clothing produced by the method has high sorbite content, does not have abnormal structures such as net-shaped carbide and the like, is beneficial to direct drawing of customers in the subsequent process, and ensures that the prepared card clothing has good wear resistance and long service life due to high surface quality and low decarburized layer.

The technical scheme adopted by the invention for solving the problems is as follows: a high-strength long-life steel wire for card clothing comprises the following chemical components in percentage by mass: c: 0.85% -0.95%, Mn: 0.45% -0.60%, Si: 0.15% -0.35%, Nb: 0.010% -0.040%, V: 0.10 to 0.50 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.015 percent of S, less than or equal to 0.06 percent of Cr, less than or equal to 0.05 percent of Ni, less than or equal to 0.05 percent of Cu, and the balance of Fe and inevitable impurities.

Because of the high requirements on the structure, segregation, net-shaped carbide and inclusion of the card clothing steel; mn, Si and Cr elements with larger proportion are often added into the conventional card clothing steel to improve the strength, hardness, plasticity and corrosion resistance of steel, refine the interlayer spacing of pearlite plates, but in the invention, because of high requirement on inclusion, in order to reduce the generation of oxide inclusion, Mn and Si elements which are lower than the conventional card clothing steel are used, and the addition of Cr elements is cancelled; the reduction of the Mn and Si contents can bring the falling point of the inclusions close to the low melting point region of MnO-SiO2-Al2O3 series, and for the card clothing steel deoxidized by Si-Mn, the inclusions are mainly MnO-Al2O3-SiO2 series (from the deoxidized product) and CaO-Al2O3-SiO2 series (from the slag). For the MnO-Al2O3-SiO2 system, the ideal inclusions should be manganese aluminum garnet (3MnO-Al2O3-3SiO2) and its surrounding low melting point region, CaO-Al2O3-SiO2-MnO system melting point is below 1400 ℃; if the inclusion is controlled in the area, the MnO-Al2O3-SiO 2-based inclusion, Mn and Si content can influence the drop point of the inclusion, so that the inclusion can obtain better plasticity, and the plasticity and harm reduction of the inclusion are realized.

For card clothing steel wires, the strength and the surface shrinkage of wire rods are also key indexes, in order to meet the strength requirements of customers, the design with high C content is used, and simultaneously, the wire rods are subjected to sorbitizing and carbide precipitation prevention through the controlled rolling and cooling technology of wire rod processing so as to meet the strength and surface shrinkage requirements of customers on steel.

The manufacturing method of the steel wire for the card clothing adopts a production process of KR molten iron treatment, converter smelting, LF refining, continuous casting of square billets, heating, controlled rolling and controlled cooling. The core of the process scheme is to perform controlled rolling and controlled cooling treatment on a high speed line by taking a continuous casting square billet as a raw material, and the process comprises the steps of billet treatment, heating temperature control, initial rolling temperature control, final rolling temperature control, spinning temperature and cooling control after spinning.

The heating temperature is strictly controlled when the card clothing steel hot rolling wire rod is rolled, decarburization is reduced as much as possible, namely the preheating section of a heating furnace is less than or equal to 750 ℃, the first section temperature of the heating furnace is 790-880 ℃, the second section temperature of the heating furnace is 950-1020 ℃, the temperature of the soaking section is 1000-1200 ℃, the first section of the heating furnace is 30min, the second section is 30min and the soaking section is 40 min.

The technological parameters are strictly controlled when the card clothing steel hot-rolled wire rod is rolled, namely the rolling temperature is 1000-1100 ℃, the high-pressure water descaling pressure is more than or equal to 180Mpa, the high-pressure water descaling is followed by the primary rolling, the intermediate rolling, the pre-finish rolling, the module feeding and the wire spinning, the finish rolling is an important process for ensuring the size of the wire rod before the wire spinning, the finish rolling temperature needs to be controlled to be about 1000 ℃, and the diameter of the wire rod after the finish rolling is less than 60 mm. The finish-rolled card clothing is cooled by water through steel, the temperature of the water through cooled card clothing is controlled between 900 ℃ and 960 ℃, the cooling is to control the spinning temperature in a proper range, the water through cooling cost is low, and the water flow can be controlled to control the cooling strength; and the wire rod is cooled through water after being rolled in a reducing sizing mill, the reducing sizing mill is used for controlling the final size and the out-of-roundness of the wire rod within a standard range, the reduction rate is about 15 percent generally, the cooling and water passing after reducing sizing are mainly used for controlling the spinning temperature, the cooling and water passing cost is low, and finally the spinning temperature is controlled to be 850-950 ℃.

After spinning, performing controlled cooling by air cooling, wherein the speed of an initial roller way after spinning is 0.75-0.95 m/s, the cooling temperature interval in the stage is 900-700 ℃, the cooling speed is controlled at 15-20 ℃/s so as to control the precipitation of reticular carbide and the size of pearlite clusters, the grain size is about 7 grades, and the phase change from austenite to pearlite has already occurred in the stage; the subsequent roller way gradually increases by 0.01-0.02 m/s, the cooling temperature range in the stage is 700-600 ℃, the cooling speed is controlled at 12-15 ℃/s, the spacing between the pearlite plates is controlled at 0.1-0.15 um, and part of pearlite can be converted into sorbite in the process; the first ten parts of the heat preservation cover are all opened, the first ten parts of the heat preservation cover correspond to the end of phase change of the wire rod, the heat preservation cover is opened to ensure the air cooling intensity, when the temperature reaches about 600 ℃, the subsequent heat preservation cover is closed, the heat preservation cover is closed when the phase change is about to end, the phase change time is prolonged, the wire rod can be fully subjected to phase change, the full phase change time of transformation from pearlite to a sorbite is ensured, the tissue uniformity is ensured, the precipitation of reticular carbide is inhibited, and the thickness of the iron scale is controlled. In the whole cooling control process, the air speed of each cooling stage on the stelmor air cooling line is controlled by adjusting the power and the air quantity of the fan.

After air cooling to 600-650 ℃, the rest heat-insulating covers are closed, so that the phase transformation region is completely transformed from an austenite region to a pearlite region, thereby inhibiting the precipitation of net-shaped carbide and controlling the thickness of iron scale. The wire rod is rapidly cooled to below 700 ℃ from the spinning temperature of 900 ℃, a reticular carbide precipitation interval (700-750 ℃) can be avoided, the phase transition temperature is controlled to be 600-650 ℃, the structure is fully phase-changed during subsequent heat preservation, the structure is more uniform, and the formation of iron scale is inhibited.

Compared with the prior art, the invention has the advantages that:

according to the invention, through reasonable component design and a stelmor air cooling line air cooling process for rolling the subsequent altitude, the wire rod is rapidly cooled to below 700 ℃ from the spinning temperature of 900 ℃, a reticular carbide precipitation interval (700-750 ℃) can be avoided, the phase transition temperature is controlled to be 600-650 ℃, the tissue is fully phase-changed during subsequent heat preservation, the tissue is more uniform, and the formation of iron oxide scales is inhibited. The net carbide of the finished product is inhibited and the evenness of the poker is improved by increasing the cooling rate and the contact area of the wire; not only improves the quality of finished products, but also reduces the production cost.

Drawings

FIG. 1 is a diagram showing the microstructure and the pearlite block spacing of a steel wire rod according to example 1 of the present invention.

FIG. 2 is a graph showing the microstructure and pearlite plate spacing of the steel wire rod of example 2 of the present invention.

Detailed Description

The present invention will be further described with reference to examples.

Example 1

Smelting 100 tons of steel with the chemical composition shown in the specification, continuously casting, and manufacturing a continuous casting slab with the cross section size of 200mm multiplied by 200mm or 390mm multiplied by 510mm, wherein the chemical composition of the obtained continuous casting slab comprises the following components in percentage by mass: c: 0.92%, Mn: 0.50%, Si: 0.20%, Nb: 0.035%, V: 0.45 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.015 percent of S, less than or equal to 0.06 percent of Cr, less than or equal to 0.05 percent of Ni, less than or equal to 0.05 percent of Cu, and the balance of Fe and inevitable impurities.

Heating the continuous casting billet to more than 1000 ℃, controlling the residual oxygen content in the furnace to be below 6%, discharging the continuous casting billet after heating for 2 hours, and rolling after descaling by high-pressure water: the initial rolling temperature is 1100 ℃, the rolling process is divided into 39 passes of rolling, the rolling speed is set to be 40m/s, the final specification after rolling is phi 5.5, the rolling is divided into four stages, the deformation rates of the stages are different, air cooling is adopted for spinning after rolling, the air flow of a fan is controlled to control the cooling speed, and the normal tissue is ensured. The spinning temperature is controlled at 850 ℃; after rolling is finished, cooling the wire rod through a stelmor air cooling line, matching the roller way speed, the rolling speed and the roller way length in order to realize the balanced cooling rate on a cooling roller way, wherein the roller way length is 108m, the initial roller way speed is 0.85m/s, and then increasing according to 0.02m/s, fans are arranged under the roller way at intervals of 3m, wherein the 1-2 # fan corresponds to 900-700 ℃, the 3-4 # fan corresponds to 700-650 ℃, the 1# fan opening degree is 80%, the 2# fan opening degree is 80%, the 3# fan opening degree is 30%, the 4# fan opening degree is 25%, the 5# fan opening degree is 25%, the 6# fan opening degree is 15%, and all subsequent heat-insulating covers are closed; after the wire rod is cooled by the air cooling line, a uniform sorbite structure is formed, the sorbite content is more than 95%, and the balance is ferrite. After the wire rod is off-line, the mechanical property and the structure of the wire rod are detected by aging treatment of a sample, and the mechanical property indexes of the wire rod are as follows: tensile strength of about 1250Mpa, face shrinkage: 42%; the metallographic structure of the wire rod is a uniform sorbite structure shown in figure 1, the sorbite proportion is more than 95%, the interlayer spacing is 0.08-0.12 um, and the size of inclusions is controlled to be less than 15 um.

Example 2

Smelting 100 tons of steel with the chemical composition shown in the specification, continuously casting, and manufacturing a continuous casting slab with the cross section size of 200mm multiplied by 200mm or 390mm multiplied by 510mm, wherein the chemical composition of the obtained continuous casting slab comprises the following components in percentage by mass: c: 0.92%, Mn: 0.50%, Si: 0.20%, Nb: 0.02%, V: 0.45 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.015 percent of S, less than or equal to 0.06 percent of Cr, less than or equal to 0.05 percent of Ni, less than or equal to 0.05 percent of Cu, and the balance of Fe and inevitable impurities.

Heating the continuous casting slab to over 1200 ℃, controlling the residual oxygen content in the furnace to be below 6%, keeping the temperature for 3 hours, discharging the continuous casting slab out of the furnace, and rolling the continuous casting slab after descaling by high-pressure water: the initial rolling temperature is 1050 ℃, the rolling process is divided into 39 passes of rolling, the rolling speed is set to be 40m/s, and the spinning temperature is controlled to be 900 ℃; after rolling, cooling the wire rod by a stelmor air cooling line, matching the roller speed, the rolling speed and the roller length to realize balanced cooling rate on a cooling roller, wherein the roller speed of 0.95m/s is used, the subsequent roller speed is increased progressively according to 0.03m/s, the opening degree of a No. 1 fan is 85%, the opening degree of a No. 2 fan is 85%, the opening degree of a No. 3 fan is 35%, the opening degree of a No. 4 fan is 25%, the opening degree of a No. 5 fan is 25%, the opening degree of a No. 6 fan is 15%, and all subsequent heat-insulating covers are closed; after the wire rod is cooled by the air cooling line, a uniform sorbite structure is formed, the sorbite content is more than 95%, and the balance is ferrite. After the wire rod is off-line, the mechanical property and the structure of the wire rod are detected by aging treatment of a sample, and the mechanical property indexes of the wire rod are as follows: tensile strength 1300Mpa, face shrinkage: 41 percent; the metallographic structure of the wire rod is a uniform sorbite structure shown in figure 2, the sorbite proportion is more than 95%, the interlayer spacing is 0.09-0.13 um, and the size of inclusions is controlled to be less than 15 um.

Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that modifications and variations of the present invention are possible to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength long-life steel wire for card clothing is characterized in that the chemical components of the steel for card clothing are designed as follows according to mass percentage: c: 0.85% -0.95%, Mn: 0.45% -0.60%, Si: 0.15% -0.35%, Nb: 0.010% -0.040%, V: 0.10 to 0.50 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.015 percent of S, less than or equal to 0.06 percent of Cr, less than or equal to 0.05 percent of Ni, less than or equal to 0.05 percent of Cu, and the balance of Fe and inevitable impurities.

2. A high-strength long-life wire rod for card clothing as claimed in claim 1, characterized in that: the maximum inclusion size of the card clothing steel is controlled below 15um, and the drop point of the inclusions is controlled in a low melting point area.

3. A high-strength long-life wire rod for card clothing as claimed in claim 1, characterized in that: the tensile strength of the card clothing steel is 1200-1350 Mpa, the surface shrinkage is more than 30%, and the center segregation rating is not more than 1 grade according to GB/T18254.

4. A high strength long life wire rod for card clothing according to claim 1, characterized in that: the metallographic structure of the steel for card clothing is a sorbite structure, the sorbite rate is more than or equal to 95 percent, and the balance is ferrite.

5. A method for manufacturing a high-strength long-life wire rod for card clothing according to claim 1, characterized in that: the method adopts a KR molten iron treatment-converter smelting-LF refining-continuous casting square billet-heating-controlled rolling-controlled cooling production process.

6. The method of manufacturing a high strength long life wire rod for card clothing as claimed in claim 5, wherein: the heating process of the continuous casting billet before rolling is specifically that the preheating section of a heating furnace is less than or equal to 750 ℃, the first-section temperature of the heating furnace is 790-880 ℃, the second-section temperature of the heating furnace is 950-1020 ℃, the temperature of the soaking section is 1000-1200 ℃, the first-section temperature of the heating furnace is 30min, the second-section temperature is 30min, and the soaking section is 40 min.

7. A method of manufacturing a high strength long life wire rod for card clothing according to claim 6, wherein: the controlled rolling process specifically comprises the steps of heating, performing high-pressure water descaling on a continuous casting square billet, wherein the pressure is more than or equal to 180Mpa, performing primary rolling, intermediate rolling, pre-finish rolling, reducing sizing and spinning after the high-pressure water descaling, wherein the rolling temperature is 1000-1100 ℃, the finish rolling temperature is controlled to be about 1000 ℃, the card clothing after the finish rolling is cooled by steel in a water-penetrating mode, and the temperature is controlled to be 900-960 ℃ after the water-penetrating cooling; after entering a reducing sizing mill for rolling, carrying out water cooling again; finally, controlling the spinning temperature to be 850-950 ℃.

8. A method of manufacturing a high strength long life wire rod for card clothing according to claim 7, wherein: after spinning is finished, air cooling is adopted for controlled cooling, the temperature range of the first stage is 900-700 ℃, and the cooling speed is controlled at 15-20 ℃/s; the temperature interval of the second stage is 700-600 ℃, the cooling speed is controlled at 12-15 ℃/s, and the temperature of the third stage is kept at about 600-650 ℃ for about 60 s.

9. The method of manufacturing a high strength long life steel wire rod for card clothing as claimed in claim 8, wherein: the cooling control effect is achieved by combining the control of the speed of the roller way during cooling control, the initial speed of the roller way is 0.75-0.95 m/s, the subsequent roller ways are gradually increased by 0.01-0.03 m/s, and when the surface temperature of the cloth steel reaches about 600-650 ℃, the subsequent heat-insulating cover of the roller way is closed, so that the cloth steel maintains phase change for a period of time in the heat-insulating cover, and the uniform sorbite structure is ensured to be formed.

10. A method of manufacturing a high strength long life wire rod for card clothing as claimed in claim 8, wherein: in the cooling control stage, when the temperature reaches 700-600 ℃, the spacing between pearlite pieces of the cloth steel is ensured to be 0.1-0.15 um by controlling the roller speed and adjusting the air volume.