CN114574679B

CN114574679B - Carbon steel hard wire rod for steel wire rope and manufacturing method thereof

Info

Publication number: CN114574679B
Application number: CN202210336877.2A
Authority: CN
Inventors: 陶立志; 李文武; 邱雪; 王雪威; 毛威昂
Original assignee: Jianlong Beiman Special Steel Co Ltd
Current assignee: Jianlong Beiman Special Steel Co Ltd
Priority date: 2022-03-31
Filing date: 2022-03-31
Publication date: 2023-10-24
Anticipated expiration: 2042-03-31
Also published as: CN114574679A

Abstract

A carbon steel hard wire rod for a steel wire rope and a manufacturing method thereof belong to the technical field of carbon steel wire rod production. The invention aims to solve the technical problem of improving the uniformity of carbon steel hard wire rods for steel wire ropes. The chemical composition of the invention is 0.80-0.82wt% of C, 0.20-0.25wt% of Si, 0.56-0.605wt% of Mn, 0.05wt% of Cr, 0.05wt% of P, 0.015wt% of S, 0.03wt% of Ni, 0.03wt% of Cu, 0.03wt% of Mo, 0.005wt% of Al, 0.005wt% of Ti and the balance of Fe. The invention eliminates Ni and V alloy elements, optimizes Mn content to 0.56-0.60%, reduces production cost, has no abnormal structures such as grain boundary cementite, martensite and the like, and greatly improves structural and performance uniformity.

Description

Carbon steel hard wire rod for steel wire rope and manufacturing method thereof

Technical Field

The invention belongs to the technical field of carbon steel wire rod production; in particular to a carbon steel hard wire rod for a steel wire rope and a manufacturing method thereof.

Background

The high-strength steel wire rope is widely applied to enterprises such as mines, metallurgy, machinery, ports, stations, airports, industrial and mining and the like. And higher requirements are put on the service life of the steel wire rope according to different application environments. The common wire rods for the high-strength steel wire ropes mostly adopt C-Si-Mn components, and the wire rod cooling control process is unreasonable, so that the grain boundary cementite and core martensite are extremely easy to appear, and the service life of the steel wire ropes is seriously affected due to the rapid reduction of the plastic toughness of the material. Each strand of steel wire of the steel wire rope is formed by twisting after drawing a wire rod (assisted by heat treatment), and the performance difference of each strand of steel wire directly influences the uniformity of the performance of the steel wire rope.

The invention patent ZL201010291415.0, a high-strength high-carbon steel wire rod and a production method thereof, refers to controlling parameters such as molten steel components, wire-laying temperature of rolled pieces, wire rod phase transition temperature and the like, and can improve the tensile strength of the wire rod to 1200-1300MPa and the surface shrinkage rate to be more than 30 percent. However, the material component C, mn applied by the technology is high in content, the tensile strength of the finished product can reach 1200MPa as long as the sorbite rate of the finished product is higher than 80%, and the technology does not list important indexes of sorbite rate, decarburized layer depth and tissue uniformity which influence the performance of the high-strength hard wire rod.

The invention patent ZL201811031176.8, a production method of a wire rod for 1860-level high-strength galvanized steel wire ropes, proposes that Cr and V composite microalloy is adopted, and a proper production process is combined, so that the produced wire rod has high strength and excellent plasticity, and the tensile strength of a finished galvanized steel wire produced by the wire rod reaches more than 1860 MPa. However, the technology adopts Cr, V and other alloy elements, the Mn content reaches 0.60-0.80%, and the alloy cost is high. Secondly, water cooling is adopted to easily generate quenching structures, and grain boundary cementite indexes which have important influence on the drawing performance of high-carbon steel are not illustrated.

Disclosure of Invention

The invention aims to provide a carbon steel hard wire rod for a steel wire rope, which has good uniformity of steel wire performance, and a manufacturing method thereof.

The invention is realized by the following technical scheme:

a carbon steel hard wire rod for a steel wire rope comprises the chemical components of 0.80-0.82wt% of C, 0.20-0.25wt% of Si, 0.56-0.605wt% of Mn, 0.05wt% of Cr, 0.05wt% of P, 0.015wt% of S, 0.03wt% of Ni, 0.03wt% of Cu, 0.03wt% of Mo, 0.005wt% of Al, 0.005wt% of Ti and the balance of Fe.

The chemical components of the carbon steel hard wire rod for the steel wire rope are 0.81wt% of C, 0.22wt% of Si, 0.58wt% of Mn, 0.05wt% of Cr, 0.010wt% of P, 0.006wt% of S, 0.01wt% of Ni, 0.02wt% of Cu, 0.01wt% of Mo, 0.004wt% of Al, 0.001wt% of Ti and the balance of Fe.

The invention relates to a manufacturing method of a carbon steel hard wire rod for a steel wire rope, which comprises a converter smelting step, wherein tapping components in the converter smelting process are regulated according to an internal control lower limit to reduce carburetion in a refining process, and are stirred to increase nitrogen content, wherein the content of C is 0.74-77wt%, the content of Si is 0.14-0.20wt%, the content of Mn is 0.52-0.56wt%, the content of Cr is less than or equal to 0.08wt%, the content of P is less than or equal to 0.018wt%, and the tapping temperature is 1600-1640 ℃, and steel ladle argon is subjected to bottom blowing strong stirring in the tapping process.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, disclosed by the invention, 80kg of calcium silicate and barium are added after 30 tons of steel are smelted and tapped by a converter, 600kg of lime and 9kg of silicon-manganese alloy are added after 40 tons of steel are tapped, 150kg of fluorite is added after 50 tons of steel are tapped, the alloy adopts a low-aluminum alloy, and the Al content in the steel is controlled below 0.006 wt%.

The invention relates to a manufacturing method of a carbon steel hard wire rod for a steel wire rope, which comprises the steps of LF refining after converter smelting, and adding deoxidizing agents in the LF refining process in the following sequence: 50kg of fluorite particles, 100kg of lime, 40kg of carbon powder and 75kg of silicon carbide are added in the first power transmission, 100kg of lime, 200kg of silica, 45kg of silicon carbide and 25kg of carbon powder are added in the second power transmission, the residual time is deoxidized by adopting silicon carbide, and the accumulated addition of the silicon carbide is less than or equal to 20kg.

The invention relates to a method for manufacturing a carbon steel hard wire rod for a steel wire rope, wherein the refining time of white slag is 15-25 minutes, and the refining slag is prepared according to SiO (silicon dioxide) ₂ 15-23wt% of CaO, 45-55wt% of Al ₂ O ₃ 6 to 10 weight percent of MgO, less than or equal to 8 weight percent of FeO+MnO, less than or equal to 0.8 weight percent of FeO+MnO, 2.5 to 3.0 weight percent of slag system alkalinity R, adjusting the components to 0.80 to 0.82 weight percent of C, 0.20 to 0.25 weight percent of Si, 0.56 to 0.60 weight percent of Mn, less than or equal to 0.08 weight percent of Cr, less than or equal to 0.018 weight percent of P, less than or equal to 0.015 weight percent of S, less than or equal to 0.006 weight percent of Al and less than or equal to 0.005 weight percent of Ti, adding 70kg of carbonized rice husk into a continuous casting machine at the temperature of 1515 to 1535 ℃ for casting.

The invention relates to a manufacturing method of a carbon steel hard wire rod for a steel wire rope, which is characterized in that after LF refining, a billet continuous casting machine is used for continuous casting, and in the continuous casting process of the billet continuous casting machine, a continuous casting billet adopts static light reduction total reduction of 15mm, tension leveler pressure of 30bar,1# tension leveler reduction of 0mm,2# tension leveler reduction of 2mm,3# tension leveler reduction of 5mm,4# tension leveler reduction of 5mm and 5-6# tension leveler reduction of 3mm.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, steel billets are heated after continuous casting of billets, the temperature of a heating preheating section of a heat accumulating type heating furnace is 870-930 ℃, the temperature of a heating section is 1040-1080 ℃, the temperature of a soaking section is 1070-1100 ℃, the heating time is 120-180min, and the residual oxygen content in the furnace is controlled below 1.5%.

The invention relates to a manufacturing method of a carbon steel hard wire rod for a steel wire rope, which comprises the steps of controlling rolling and cooling after billet heating, controlling cogging temperature in the rolling process to 900-980 ℃, controlling feeding finishing mill group temperature to 870-900 ℃ and wire-laying temperature to 890-910 ℃ by adopting large rolling reduction of 53-55 mm.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, after a steel billet is heated, rolling and cooling are controlled, the speed of a Cheng Sitai mol air cooling wire roll is controlled to be 0.8m/s at the first section, the advance coefficient of the 2 nd section to the 12 th section is 3%, the advance coefficient of the 13 th section is 0.9%, the opening degree of the first two groups of middle fans is 70%, and the opening degree of fans at two sides is 75%; the opening degree of the middle fans of the third group is 30%, and the opening degree of the fans at the two sides is 40%; the rest fans are closed, the 1 st-6 th section roller way heat preservation cover is opened, the 7 th-12 th section roller way heat preservation cover is closed, and the 13 th section roller way heat preservation cover is opened.

According to the carbon steel hard wire rod for the steel wire rope, the carbon elements are helpful for improving the material strength, the tensile strength of a finished steel wire reaches 1860MPa, the carbon content is improved to the highest, and the performance of the common steel wire rope material is improved by improving the carbon content. However, since segregation is more likely to occur as the carbon element is higher, grain boundary cementite is likely to form in grain boundaries even when controlled cooling is not performed, and thus the drawing performance of the wire rod is greatly reduced, too high carbon content is not preferably controlled. The carbon content is controlled to be 0.80-0.82% after two comprehensive consideration, and the cold control process after rolling can ensure the tensile strength of the finished steel wire and the drawing quality of the wire rod.

According to the carbon steel hard wire rod for the steel wire rope, the silicon element is taken as a deoxidizing element, the content of the silicon element is calculated according to the deoxidizing requirement of the material and is not lower than 0.20%, but is not too high, so that a large amount of silicon oxide inclusion generated in the material is prevented from affecting the drawing performance of a finished wire rod, and the silicon content is comprehensively considered to be controlled to be 0.20-0.25%.

The carbon steel hard wire rod for the steel wire rope, disclosed by the invention, has the advantages that the manganese element serving as a weak deoxidizer can be combined with sulfur and oxygen for eliminating the thermal embrittlement effect of materials, and the thermal processing performance of steel is improved. The performance of the material is gradually improved along with the increase of the manganese content, but the manganese content is controlled to be below 1.0 percent so as not to reduce the plasticity of the material to influence the drawing performance of the finished wire rod, and the manganese content is generally controlled to be 0.60-0.80 percent in the same industry. Considering the production cost, the cold control process can increase the sorbite proportion and further improve the material performance, and can control the manganese content to be 0.56-0.60%.

The carbon steel hard wire rod for the steel wire rope has the advantages that phosphorus and sulfur are harmful impurity elements in steel, and in order to ensure that the wire rod has good plasticity, the lower the phosphorus and sulfur content is, the better the phosphorus and sulfur content is, the phosphorus and sulfur content of the material is controlled below 0.015%.

According to the carbon steel hard wire rod for the steel wire rope, the titanium and aluminum elements in the material are easy to form high-melting-point inclusions, the hardness is higher than that of a material matrix, the inclusions are not easy to deform, and the drawing quality of a finished wire rod is seriously affected, so that the titanium and aluminum content is controlled to be the lowest, the titanium content in the material is controlled to be below 0.004%, and the aluminum content is controlled to be below 0.006%.

According to the carbon steel hard wire rod for the steel wire rope, the chromium element blocks diffusion of carbon atoms in the material and stabilizes an austenite phase region, so that the phase transition temperature of the material is reduced, carbide can be precipitated at a lower temperature, precipitation of grain boundary cementite during wire rod cooling control is affected by excessive chromium content, and the drawing performance of the wire rod is reduced, and therefore the chromium content of the material is controlled to be below 0.05%.

According to the carbon steel hard wire rod for the steel wire rope, ni and V alloy elements are eliminated, meanwhile, mn content is optimized to be 0.56-0.60%, production cost is reduced, tensile strength is 1100-1200MPa, shrinkage rate is more than 35%, sorbite proportion is more than 95%, grain size is 8.5, decarburization is less than or equal to 0.9% D, abnormal structures such as grain boundary cementite and martensite are avoided, and structural and performance uniformity is greatly improved.

Drawings

FIG. 1 is a metallographic photograph of the grain size of a carbon steel hard wire rod for a steel wire rope, prepared by a method according to an embodiment;

FIG. 2 is a metallographic photograph of the structure of a carbon steel hard wire rod for a steel wire rope, prepared by a method according to an embodiment;

FIG. 3 is a photograph of a cross-section of a decarbonized carbon steel hard wire rod for a steel wire rope made by a method according to an embodiment;

fig. 4 is a SEM photograph of the spacing between sheets of a carbon steel hard wire rod for a steel wire rope according to a method of one embodiment.

Detailed Description

The first embodiment is as follows:

a carbon steel hard wire rod for a steel wire rope comprises the chemical components of 0.81wt% of C, 0.22wt% of Si, 0.58wt% of Mn, 0.05wt% of Cr, 0.010wt% of P, 0.006wt% of S, 0.01wt% of Ni, 0.02wt% of Cu, 0.01wt% of Mo, 0.004wt% of Al, 0.001wt% of Ti and the balance of Fe.

The manufacturing method of the carbon steel hard wire rod for the steel wire rope comprises a converter smelting step, wherein steel tapping components in the converter smelting process are regulated according to an inner control lower limit to reduce carburetion in a refining process, stirring is carried out to increase nitrogen content control, the content of C is 0.74-77wt%, the content of Si is 0.14-0.20wt%, the content of Mn is 0.52-0.56wt%, the content of Cr is less than or equal to 0.08wt%, the content of P is less than or equal to 0.018wt%, and the steel tapping temperature is 1600-1640 ℃, and steel ladle argon is subjected to bottom blowing strong stirring in the steel tapping process.

A method for manufacturing a carbon steel hard wire rod for a steel wire rope according to the present embodiment,

the addition of Ti, mo and Ni waste steel is forbidden in converter smelting so as to prevent the generation of high-hardness oxide and the reduction of the drawing performance of the material. The tapping component is regulated according to the internal control lower limit to reduce carburetion in the refining process, and the consumption of final deoxidized aluminum and silicon-manganese alloy is controlled to ensure the content of residual aluminum and titanium in steel.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, disclosed by the embodiment, 80kg of calcium silicate and barium are added after 30 tons of steel are tapped from a converter smelting, 600kg of lime and 9kg of silicon-manganese alloy are added after 40 tons of steel are tapped, 150kg of fluorite is added after 50 tons of steel are tapped, low-aluminum alloy is adopted as the alloy, and the Al content in steel is controlled below 0.006 wt%.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, LF refining is performed after converter smelting, and the addition sequence of deoxidizing agents in the LF refining process is as follows: 50kg of fluorite particles, 100kg of lime, 40kg of carbon powder and 75kg of silicon carbide are added in the first power transmission, 100kg of lime, 200kg of silica, 45kg of silicon carbide and 25kg of carbon powder are added in the second power transmission, the residual time is deoxidized by adopting silicon carbide, and the accumulated addition of the silicon carbide is less than or equal to 20kg.

The method for manufacturing the carbon steel hard wire rod for the steel wire rope, disclosed in the embodiment, has the advantages that the white slag refining time is 15-25 minutes, and the refining slag is prepared according to SiO (silicon dioxide) ₂ 15-23wt% of CaO, 45-55wt% of Al ₂ O ₃ 6 to 10 weight percent of MgO, less than or equal to 8 weight percent of FeO+MnO, less than or equal to 0.8 weight percent of FeO+MnO, 2.5 to 3.0 weight percent of slag system alkalinity R, adjusting the components to 0.80 to 0.82 weight percent of C, 0.20 to 0.25 weight percent of Si, 0.56 to 0.60 weight percent of Mn, less than or equal to 0.08 weight percent of Cr, less than or equal to 0.018 weight percent of P, less than or equal to 0.015 weight percent of S, less than or equal to 0.006 weight percent of Al and less than or equal to 0.005 weight percent of Ti, adding 70kg of carbonized rice husk into a continuous casting machine at the temperature of 1515 to 1535 ℃ for casting.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, LF refining is followed by continuous casting by a continuous casting machine, continuous casting is carried out by the continuous casting machine, the continuous casting is carried out by adopting static light reduction total reduction of 15mm, tension leveler pressure of 30bar,1# tension leveler reduction of 0mm,2# tension leveler reduction of 2mm,3# tension leveler reduction of 5mm,4# tension leveler reduction of 5mm and 5-6# tension leveler reduction of 3mm.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, a square billet continuous casting machine is used for continuously casting six-machine six-flow arc 200mm square billet continuous casting machines, a slag blocking wall is adopted in the casting process, an integral water gap is adopted, a submerged water gap sealing gasket has the argon sealing capability, and the liquid level insertion depth is 100-120mm. Filling argon into the middle ladle for blowing 3min before casting, protecting the whole process by argon, wherein the mold flux adopts special mold flux of peritectic steel, the start pulling speed is controlled to be 0.60m/min, the process pulling speed is 1.40m/min, and the water flow of the crystallizer is 135m ³ And/h, the fluctuation of the liquid level in the crystallizer is less than or equal to +/-3 mm.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, billet heating is performed after billet continuous casting, the temperature of a heating preheating section of a heat accumulating type heating furnace is 930 ℃, the temperature of a heating section is 1058 ℃, the temperature of a soaking section is 1082 ℃, the heating time is 154min, and the residual oxygen content in the furnace is controlled below 1.5%.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, after a steel billet is heated, rolling and cooling are controlled, the cogging temperature in the rolling control process is 900-980 ℃, the large reduction is 53-55mm, the feeding finishing mill group temperature is 870-900 ℃, and the spinning temperature is 906 ℃.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, after a steel billet is heated, rolling and cooling are controlled, the speed of a Cheng Sitai mol air cooling wire roll is controlled to be 0.8m/s at the first section, the advance coefficient of the 2 nd section to the 12 th section is 3%, the advance coefficient of the 13 th section is 0.9%, the opening degree of the first two groups of middle fans is 70%, and the opening degree of the fans at two sides is 75%; the opening degree of the middle fans of the third group is 30%, and the opening degree of the fans at the two sides is 40%; the rest fans are closed, the 1 st-6 th section roller way heat preservation cover is opened, the 7 th-12 th section roller way heat preservation cover is closed, and the 13 th section roller way heat preservation cover is opened.

The manufacturing method of the carbon steel hard wire rod for the steel wire rope, disclosed by the embodiment, adopts a Steyr air cooling line for controlling cooling, the total length of the cooling line is 105.3 meters, 10 groups of 30 centrifugal fans are arranged, 3 fans in each group are sequentially arranged in a left-right manner, the air quantity of the fans can be independently adjusted, the power of the fans is 160KW, and the maximum air quantity is 120000m ³ And/h. The air cooling line is provided with a heat preservation cover to realize delay cooling, the cooling speed range is 0.5-20 ℃/s, and the delay cooling and standard cooling can be realized. The air cooling line roller way is divided into 13 sections, the length of the first section is 3.5 meters, the lengths of the 2 nd section and the 12 th section are respectively 8.8 meters, the 13 th section is 5 meters, and each section of roller way is provided with an independent motor to realize the sectional control of the roller way speed. Except the first section of roller way, each of the other sections is provided with 2 heat preservation covers.

According to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, roller speed setting of each section of a stelmor air cooling line is shown in table 1, air volume setting is shown in table 2, control of a heat preservation cover is shown in table 3, and coiling temperature of each position of an air cooling roller table is shown in table 4:

table 1 stelmor air-cooled line section roller speed

Roller way	1 section	2 segments	3 segments	4 sections	5 segments	6 segments	7 segments	8 sections of	9 sections	10 sections	11 sections	12 sections	13 sections
														Coefficient of advance%	——	1	1	1	1	1	1	1	1	1	1	1	0.9
Roll speed m/s	0.8	0.81	0.82	0.82	0.83	0.84	0.85	0.86	0.87	0.87	0.88	0.89	0.90
														Length m of roller table	3.5	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	8.8	5.0

TABLE 2 Steyr air-cooled line air volume

Blower fan

Group 1

Group 2

Group 3

Group 4

Group 5

6 groups

7 groups

8 groups of

9 groups

10 groups

Left side

75％

40％

Switch for closing

Intermediate part

70％

30％

Switch for closing

Right side

75％

40％

Switch for closing

TABLE 3 Steyr air cooled line thermal shield control

Roller way

1 section

2 segments

3 segments

4 sections

5 segments

6 segments

7 segments

8 sections of

9 sections

10 sections

11 sections

12 sections

13 sections

On/off state

Opening the valve

Closing

Opening the valve

TABLE 4 temperature of coil at each position of air-cooled roller table of Steyr air-cooled line

Position of	Spinning device	Group 1	Group 2	Group 3	Group 4	Group 5	6 groups	7 groups	8 groups of	9 groups	10 groups
												Left side	906	716	635	612	609	601	577	561	533	511	483
Intermediate part	897	703	622	601	597	588	573	553	531	506	474
												Right side	903	710	627	607	602	600	582	562	541	509	488
Extremely poor	9	13	13	11	12	13	9	9	10	5	14

From Table 4, it can be seen that the wire rod temperature starts to stabilize at the group 2 fan position and reaches the sorbite structure formation temperature range (550-650 ℃), and austenite starts to transform into sorbite structure. The temperature of the left side, the middle side and the right side of the wire rod is extremely 5-14 ℃, the interlayer spacing of pearlite sheets transformed in the temperature range tends to be consistent, and the sorbite rate, the grain size and the performance uniformity are high.

The carbon steel hard wire rod for the steel wire rope is characterized in that each circle of wire rod is 3.1-3.3 m long, the coil produced by the process is cut into one circle, 300mm sections are formed, 01-10 are marked in sequence, the test performance and the structure are shown in table 5, and the structure photographs are shown in fig. 1-4:

table 5 shows the properties of a carbon steel hard wire rod for a steel wire rope

As can be seen from Table 5, the tensile strength of the carbon steel hard wire rod for the steel wire rope is 1133-1154MPa, and the extremely poor tensile strength is 21MPa; shrinkage rate is 33-35% and extremely poor is 2%; the sorbite proportion is 95.8-97.3%, and the extremely poor is 1.5%; the grain size is 8.5 grade, the depth of decarburized layer is 37.55-47.63 μm (less than or equal to 0.9% D), the spacing between sorbite sheets is 0.19-0.23 μm, and no abnormal structures such as grain boundary cementite, martensite and the like exist.

As can be seen from fig. 1 of the specification, the grain size of the carbon steel hard wire rod for the steel wire rope is 8.5 grade; FIG. 2 shows that the proportion of sorbite is 95.8%, the proportion of ferrite is 4.2%, the proportion of grain boundary cementite is 0%, and the martensite is 0%; FIG. 3 shows decarburization of 47.63 μm,0.86% D; FIG. 4 shows that the spacing between the sorbite sheets is 0.23 μm.

The second embodiment is as follows:

The carbon steel hard wire rod for the steel wire rope, which is prepared by the embodiment, has the advantages that the components of steel billets cancel Ni and V alloy elements, and the Mn content is optimized to be 0.56-0.60%. The wire rod spinning temperature is controlled to 870-930 ℃, the roller speed of the first section of the stelmor air cooling line is 0.8m/s, the advance coefficient of the 2 nd section to 12 th section is 1%, and the advance coefficient of the 13 th section is 0.9%; the opening degree of the middle fans of the first two groups is 70 percent, the opening degree of the fans at the two sides is 75 percent, and the opening degree of the middle fans of the third group is 30 percent, and the opening degree of the fans at the two sides is 40 percent; the 1 st to 6 th section roller way heat preservation cover is opened, the 7 th to 12 th section roller way heat preservation cover is closed, and the 13 th section roller way heat preservation cover is opened. The production cost of the hard wire steel wire rod obtained by the process is reduced, the tensile strength is 1133-1154MPa, and the extremely poor tensile strength is 21MPa; shrinkage rate is 33-35% and extremely poor is 2%; the sorbite proportion is 95.8-97.3%, and the extremely poor is 1.5%; the grain size is 8.5 grade, the depth of decarburized layer is 37.55-47.63 μm (below 0.9% D), the spacing between sorbite sheets is 0.19-0.23 μm, and no abnormal structures such as grain boundary cementite, martensite and the like are generated.

And a third specific embodiment:

the carbon steel hard wire rod for a steel wire rope according to the second embodiment has a chemical composition of 0.81wt% of C, 0.22wt% of Si, 0.58wt% of Mn, 0.05wt% of Cr, 0.010wt% of P, 0.006wt% of S, 0.01wt% of Ni, 0.02wt% of Cu, 0.01wt% of Mo, 0.004wt% of Al, 0.001wt% of Ti, and the balance being Fe.

The specific embodiment IV is as follows:

according to the manufacturing method of the carbon steel hard wire rod for the steel wire rope, which comprises the converter smelting step, tapping components in the converter smelting process are regulated according to an internal control lower limit to reduce carburetion in the refining process, stirring is carried out to increase nitrogen content control, the content of C is 0.74-77wt%, the content of Si is 0.14-0.20wt%, the content of Mn is 0.52-0.56wt%, the content of Cr is less than or equal to 0.08wt%, the content of P is less than or equal to 0.018wt%, and the tapping temperature is 1600-1640 ℃, and steel ladle argon is strongly stirred by bottom blowing in the tapping process.

Fifth embodiment:

according to the method for manufacturing the carbon steel hard wire rod for the steel wire rope, which is described in the third embodiment, 80kg of calcium silicate and barium are added after 30 tons of steel are smelted and tapped by a converter, 600kg of lime and 9kg of silicon-manganese alloy are added after 40 tons of steel are tapped, 150kg of fluorite is added after 50 tons of steel are tapped, the alloy is low-aluminum alloy, and the Al content in the steel is controlled below 0.006 wt%.

Specific embodiment six:

according to the method for manufacturing the carbon steel hard wire rod for the steel wire rope, which is described in the third embodiment, LF refining is performed after converter smelting, and the addition sequence of deoxidizing agents in the LF refining process is as follows: 50kg of fluorite particles, 100kg of lime, 40kg of carbon powder and 75kg of silicon carbide are added in the first power transmission, 100kg of lime, 200kg of silica, 45kg of silicon carbide and 25kg of carbon powder are added in the second power transmission, the residual time is deoxidized by adopting silicon carbide, and the accumulated addition of the silicon carbide is less than or equal to 20kg.

Seventh embodiment:

the method for manufacturing a carbon steel hard wire rod for a steel wire rope according to the third embodiment, wherein the white slag refining time is 15-25 minutes, and the refining slag is SiO ₂ 15-23wt% of CaO, 45-55wt% of Al ₂ O ₃ 6 to 10 weight percent of MgO, less than or equal to 8 weight percent of FeO+MnO, less than or equal to 0.8 weight percent of FeO+MnO, 2.5 to 3.0 weight percent of slag system alkalinity R, adjusting the components to 0.80 to 0.82 weight percent of C, 0.20 to 0.25 weight percent of Si, 0.56 to 0.60 weight percent of Mn, less than or equal to 0.08 weight percent of Cr, less than or equal to 0.018 weight percent of P, less than or equal to 0.015 weight percent of S, less than or equal to 0.006 weight percent of Al and less than or equal to 0.005 weight percent of Ti, adding 70kg of carbonized rice husk into a continuous casting machine at the temperature of 1515 to 1535 ℃ for casting.

Eighth embodiment:

according to the method for manufacturing the carbon steel hard wire rod for the steel wire rope, in the third embodiment, after LF refining, continuous casting is performed by a continuous casting machine, in the continuous casting process of the continuous casting machine, the continuous casting is subjected to static light reduction total reduction of 15mm, the tension leveler pressure is 30bar, the reduction of the 1# tension leveler is 0mm, the reduction of the 2# tension leveler is 2mm, the reduction of the 3# tension leveler is 5mm, the reduction of the 4# tension leveler is 5mm, and the reduction of the 5-6# tension leveler is 3mm.

Detailed description nine:

according to the method for manufacturing the carbon steel hard wire rod for the steel wire rope, in the third embodiment, the billet is heated after continuous casting, the temperature of a heating preheating section of a heat accumulating type heating furnace is 870-930 ℃, the temperature of a heating section is 1040-1080 ℃, the temperature of a soaking section is 1070-1100 ℃, the heating time is 120-180min, and the residual oxygen content in the furnace is controlled below 1.5%.

Detailed description ten:

the method for manufacturing the carbon steel hard wire rod for the steel wire rope according to the third embodiment comprises the steps of controlling rolling and cooling after billet heating, controlling cogging temperature in the rolling process to 900-980 ℃, controlling feeding finishing mill group temperature to 870-900 ℃ and wire laying temperature to 890-910 ℃ by adopting large rolling reduction of 53-55 mm.

Eleventh embodiment:

according to the method for manufacturing the carbon steel hard wire rod for the steel wire rope, in the third embodiment, after the steel billet is heated, rolling and cooling are controlled, the rolling speed of the cooling-controlled air cooling line is Cheng Sitai mol, the rolling speed of the first section is 0.8m/s, the advance coefficient of the 2 nd section to the 12 th section is 3%, the advance coefficient of the 13 th section is 0.9%, the opening degree of the first two groups of middle fans is 70%, and the opening degree of the fans at two sides is 75%; the opening degree of the middle fans of the third group is 30%, and the opening degree of the fans at the two sides is 40%; the rest fans are closed, the 1 st-6 th section roller way heat preservation cover is opened, the 7 th-12 th section roller way heat preservation cover is closed, and the 13 th section roller way heat preservation cover is opened.

Claims

1. A manufacturing approach of the hard wire rod of carbon steel for wire rope, the chemical composition of a hard wire rod of carbon steel for wire rope is 0.80-0.82wt% C, 0.20-0.25wt% Si, 0.56-0.605wt% Mn, 0.05wt% Cr, 0.05wt% P, 0.015wt% S, 0.03wt% Ni, 0.03wt% Cu, 0.03wt% Mo, 0.005wt% Al, 0.005wt% Ti, and the balance Fe;

the method is characterized in that: the method comprises the steps of converter smelting, wherein tapping components are regulated according to an inner control lower limit to reduce carburetion in a refining process, stirring is carried out to increase nitrogen content, the content of C is 0.74-77wt%, the content of Si is 0.14-0.20wt%, the content of Mn is 0.52-0.56wt%, the content of Cr is less than or equal to 0.08wt%, the content of P is less than or equal to 0.018wt%, the tapping temperature is 1600-1640 ℃, and ladle argon is strongly stirred in a bottom blowing manner in the tapping process;

the refining time of the white slag is 15-25 minutes, and the refining slag is based on SiO ₂ 15-23wt% of CaO, 45-55wt% of Al ₂ O ₃ 6 to 10 weight percent of MgO, less than or equal to 8 weight percent of FeO+MnO, less than or equal to 0.8 weight percent of FeO+MnO, 2.5 to 3.0 weight percent of slag system alkalinity R, adjusting the components to 0.80 to 0.82 weight percent of C, 0.20 to 0.25 weight percent of Si, 0.56 to 0.60 weight percent of Mn, less than or equal to 0.08 weight percent of Cr, less than or equal to 0.018 weight percent of P, less than or equal to 0.015 weight percent of S, less than or equal to 0.006 weight percent of Al and less than or equal to 0.005 weight percent of Ti, adding 70kg of carbonized rice husk into a continuous casting machine at the temperature of 1515 to 1535 ℃ of molten steel, and casting;

heating the billet after continuous casting, wherein the temperature of a heating section of a regenerative heating furnace is 870-930 ℃, the temperature of a heating section is 1040-1080 ℃, the temperature of a soaking section is 1070-1100 ℃, the heating time is 120-180min, and the content of residual oxygen in the furnace is controlled below 1.5%;

after the billet is heated, rolling control and cooling control are performed, the roll speed of the cooling control is Cheng Sitai mol air cooling line is 0.8m/s of the roll speed of the first section, the advance coefficient of the 2 th section to the 12 th section is 3%, the advance coefficient of the 13 th section is 0.9%, the opening degree of the first two groups of middle fans is 70%, and the opening degree of the fans at the two sides is 75%; the opening degree of the middle fans of the third group is 30%, and the opening degree of the fans at the two sides is 40%; the rest fans are closed, the 1 st-6 th section roller way heat preservation cover is opened, the 7 th-12 th section roller way heat preservation cover is closed, and the 13 th section roller way heat preservation cover is opened.

2. The method for manufacturing a carbon steel hard wire rod for a steel wire rope according to claim 1, wherein: 80kg of calcium silicate and barium are added after 30 tons of steel are tapped by a converter, 600kg of lime and 9kg of silicon-manganese alloy are added after 40 tons of steel are tapped, 150kg of fluorite is added after 50 tons of steel are tapped, the alloy is low-aluminum alloy, and the Al content in the steel is controlled below 0.006 wt%.

3. The method for manufacturing a carbon steel hard wire rod for a steel wire rope according to claim 2, wherein: the converter smelting is followed by LF refining, and the addition sequence of deoxidizing agents in the LF refining process is as follows: 50kg of fluorite particles, 100kg of lime, 40kg of carbon powder and 75kg of silicon carbide are added in the first power transmission, 100kg of lime, 200kg of silica, 45kg of silicon carbide and 25kg of carbon powder are added in the second power transmission, the residual time is deoxidized by adopting silicon carbide, and the accumulated addition of the silicon carbide is less than or equal to 20kg.

4. A method of manufacturing a carbon steel hard wire rod for a wire rope according to claim 3, wherein: after LF refining, the continuous casting is performed by a billet continuous casting machine, and in the continuous casting process of the billet continuous casting machine, the total static light reduction of the continuous casting billet is 15mm, the pressure of a withdrawal and straightening machine is 30bar, the reduction of a No. 1 withdrawal and straightening machine is 0mm, the reduction of a No. 2 withdrawal and straightening machine is 2mm, the reduction of a No. 3 withdrawal and straightening machine is 5mm, the reduction of a No. 4 withdrawal and straightening machine is 5mm, and the reduction of a No. 5-6 withdrawal and straightening machine is 3mm.

5. The method for manufacturing a carbon steel hard wire rod for a steel wire rope according to claim 4, wherein: after the billet is heated, the controlled rolling and cooling are performed, the cogging temperature in the controlled rolling process is 900-980 ℃, the large rolling reduction is 53-55mm, the temperature of the finishing mill group is 870-900 ℃, and the wire laying temperature is 890-910 ℃.

6. The method for manufacturing a carbon steel hard wire rod for a steel wire rope according to claim 5, wherein: the chemical components of the carbon steel hard wire rod for the steel wire rope are 0.81wt% of C, 0.22wt% of Si, 0.58wt% of Mn, 0.05wt% of Cr, 0.010wt% of P, 0.006wt% of S, 0.01wt% of Ni, 0.02wt% of Cu, 0.01wt% of Mo, 0.004wt% of Al, 0.001wt% of Ti and the balance of Fe.