CN115011871A - Preparation method of Cu-containing ultralow-titanium bearing steel - Google Patents

Preparation method of Cu-containing ultralow-titanium bearing steel Download PDF

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CN115011871A
CN115011871A CN202210487708.9A CN202210487708A CN115011871A CN 115011871 A CN115011871 A CN 115011871A CN 202210487708 A CN202210487708 A CN 202210487708A CN 115011871 A CN115011871 A CN 115011871A
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steel
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王德勇
齐锐
卢秉军
齐峰
阚开
赵千水
张群
蒋艳菊
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Bengang Steel Plates Co Ltd
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Abstract

The invention relates to a preparation method of Cu-containing ultralow titanium bearing steel, belonging to the field of steel production. A preparation method of Cu-containing ultra-low titanium bearing steel is disclosed, wherein molten steel components are controlled in the method, and the method comprises the following steps: c: 0.80-1.20%, Si: 0.10 to 2.00%, Mn: 0.20 to 2.50%, P: less than or equal to 0.020%, S: less than or equal to 0.012 percent, Cr: 1.20 to 2.50%, Mo: less than or equal to 0.08 percent, Al: less than or equal to 0.05%, Cu: 0.25 to 0.50%, Ni: less than or equal to 0.20 percent, O: less than or equal to 0.0006 percent, Ti: less than or equal to 0.0015%, Ca: less than or equal to 0.0010%, Pb: less than or equal to 0.002%, Sb: less than or equal to 0.005%, Sn: less than or equal to 0.03%, As: less than or equal to 0.04 percent, and the balance of iron and inevitable impurities. The invention comprises the following steps: EBT electric furnace smelting → LF refining → VD vacuum degassing → continuous casting of square billet → rolling of phi 800mm bar continuous rolling mill. The method can effectively reduce the titanium content in the bearing steel, so that the bearing steel meets the quality requirement of the super-grade high-quality bearing steel, and the indexes such as inclusion content, oxygen content and the like can also meet the standard requirement.

Description

Preparation method of Cu-containing ultralow-titanium bearing steel
Technical Field
The invention relates to a preparation method of Cu-containing ultralow titanium bearing steel, belonging to the field of steel production.
Background
The bearing steel is an important steel material, nitrides in the bearing steel mainly exist in TiN or TiCN, titanium nitride is a hard and brittle inclusion and is very harmful to the fatigue life of the steel, and downstream users have increasingly strict requirements (such as inclusions, carbides and the like) on the internal metallurgical quality of the bearing steel produced by metallurgical enterprises at present and particularly have strict requirements on the size, the quantity and the distribution of large-particle inclusion TiN in the steel because (i) the titanium nitride (TiN) inclusion destroys the continuity of a steel matrix and easily generates stress concentration under the condition of external deformation force; secondly, when the steel is deformed or thermally treated, because the thermal expansion coefficients of the metal matrix and the TiN inclusions are different, an initial crack is formed at the interface of the metal and the TiN inclusions, and the initial crack is a fatigue source for further fatigue failure of the metal; and the TiN inclusions are hard and angular, so that the bearing is easy to fall off when rolling, and the fatigue life is influenced. The titanium content in the steel is reduced as much as possible, the possibility of forming titanium nitride inclusions is reduced, and the lower the requirement of the bearing steel on titanium is, the better the requirement is. GB/T18254-2016 divides the bearing steel into three grades, namely high quality, high-grade high quality and special-grade high quality, wherein the Ti content in the special-grade high quality bearing steel is required to be less than or equal to 15 ppm.
The biggest technical difficulty in smelting ultra-low titanium bearing steel is the control of titanium content, most of titanium in the steel is from ferroalloy, and the alloy used for producing the bearing steel comprises ferrochrome, ferromanganese, ferrosilicon and the like, so in order to reduce the titanium content, the currently adopted smelting method is preferred to use the alloy with lower titanium content. At present, the smelting method for producing the low-titanium bearing steel by using the low-titanium ferrochrome is easy to realize, but the requirement of controlling the titanium content cannot be met only by using the low-titanium alloy to realize the production of the ultra-low-titanium bearing steel (Ti is less than or equal to 15 ppm). The method can be realized only by matching strict technical control measures in the production process.
Disclosure of Invention
The invention aims to provide a method for producing Cu-containing ultra-low titanium bearing steel GCr15-CDT, which adopts an EBT electric furnace, external refining, continuous casting of a medium square billet and a phi 800mm bar mill to produce and manufacture Cu-containing ultra-low titanium bearing steel GCr15-CDT, thereby ensuring the indexes of low oxygen, low calcium, low inclusion content and the like of the bearing steel and ensuring that the titanium content of the bearing steel reaches the quality level of special grade high quality bearing steel.
A preparation method of Cu-containing ultra-low titanium bearing steel comprises the following steps of controlling molten steel components in percentage by mass:
c: 0.80-1.20%, Si: 0.10 to 2.00%, Mn: 0.20 to 2.50%, P: less than or equal to 0.020%, S: less than or equal to 0.012 percent, Cr: 1.20 to 2.50%, Mo: less than or equal to 0.08 percent, Al: less than or equal to 0.05 percent, Cu: 0.25 to 0.50%, Ni: less than or equal to 0.20 percent, O: less than or equal to 0.0006 percent, Ti: less than or equal to 0.0015%, Ca: less than or equal to 0.0010%, Pb: less than or equal to 0.002%, Sb: less than or equal to 0.005%, Sn: less than or equal to 0.03%, As: less than or equal to 0.04 percent, and the balance of iron and inevitable impurities.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the method comprises the following process steps: the method comprises the following steps of smelting molten steel by an EBT electric arc furnace, refining molten steel by an LF ladle refining furnace, refining molten steel by a VD vacuum degassing furnace, continuously casting a square billet, heating and rolling, wherein the step of smelting the molten steel by the EBT electric arc furnace comprises the following steps: scrap steel and molten iron are used as furnace burden, the proportion of the scrap steel is 15-35%, and the proportion of the molten iron is 65-85%; the content of the added C is more than or equal to 1.10 percent, the oxygen is oxidized, the mixture is boiled violently and flows slag automatically, the oxidation temperature is 1555-1585 ℃, the decarburization weight is more than or equal to 0.30 percent, and the steel tapping requirement is as follows: the content of C is less than or equal to 0.10%, the content of P is less than or equal to 0.010%, other residual elements are qualified, the temperature is 1635-1650 ℃, an oxidation method is adopted in the tapping process to perform alloy titanium removal treatment, namely, oxygen in steel is utilized to oxidize and remove titanium in the alloy so as to achieve the purpose of ultralow titanium content, the alloy is added in the following sequence, 8-15 kg/t of low-titanium high-chromium and 10-35 kg/t of medium manganese are added during tapping 1/4-1/3, and then 5-20 kg/t of low-carbon ferrosilicon, 8-10 kg/t of low-titanium carburant, 4-6 kg/t of active lime and 2-4 kg/t of alumina powder are added.
Furthermore, the scrap steel adopts high-quality scrap steel without impurity elements; the molten iron is low-phosphorus and low-sulfur molten iron.
In the step of smelting molten steel in the EBT electric arc furnace, calcium or calcium alloy is not allowed to be used as a deoxidizer in the whole smelting process. The whole smelting process should prevent titanium pollution, and not allow direct production after the grade of titanium-containing steel, and production must be discharged after the secondary casting of bearing steel with Ti less than or equal to 50ppm, and the ladle uses the ladle of upper casting bearing steel.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the step of refining molten steel by the LF ladle refining furnace comprises the following steps: deslagging, namely removing the slag by adopting a slag pan to remove oxidizing slag generated in the tapping process of the electric furnace so as to remove titanium dioxide in the slag and reduce titanium dioxide which is reduced into titanium in the refining process and enters into molten steel to increase titanium in the molten steel; slagging, namely adjusting Al in steel to 0.020-0.040%, controlling Al to be less than or equal to 0.050% in the whole LF process, adding 1-3 kg/t of a diffusion deoxidizer ferrosilicon powder into the first batch for diffusion deoxidation, closing a furnace door for 10min, adding the second batch, wherein the total addition is 2-4 kg/t, and taking a primary sample after the slag is white according with the requirement; ca-containing deoxidizer is not allowed to be used in the whole refining process; continuously diffusing and deoxidizing after full analysis, keeping the reducing atmosphere to the ladle, and keeping the white slag for not less than 25 min; after the deoxidation is good, adding the baked low-titanium high-chromium, medium-manganese, low-carbon ferrosilicon and waste copper alloy according to the component target control, adjusting the components to the target, and controlling the argon pressure to be 0.2-0.3 MPa in the whole process.
In the above steps, the slag is melted, the content of titanium dioxide in the slag is reduced, and the reduction of titanium is reduced.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the step of refining molten steel by the VD vacuum degassing furnace is as follows: the VD temperature is 1570-1610 ℃, Al is adjusted to 0.025-0.035% before VD is added, so that finished product Al is ensured to reach 0.015-0.025%, the vacuum degree is less than 100Pa, and the holding time is more than or equal to 20 min; after vacuum treatment, the static argon blowing time is more than or equal to 25min, the argon pressure is 0.1-0.3 MPa, and the bag temperature is controlled at 1525-1545 ℃.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the continuous casting of the square billet comprises the following steps: the temperature of a first furnace of the big ladle is 1525-1535 ℃, the temperature of continuous casting is 1505-1515 ℃, the temperature of a tundish is 1470-1475 ℃, the pulling speed is 0.75m/min, the specific water amount of secondary cooling water is 0.25L/kg, the electromagnetic stirring current of the crystallizer is 450A, the electromagnetic stirring current of the tail end is 330A, and the frequency is 8 Hz. Strictly performing whole-process protective casting, wherein the crystallizer protective slag is special high-carbon steel protective slag, and the casting blank heat preservation time is more than or equal to 30 hours.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the heating step is as follows: the heating is carried out by adopting a heat accumulating type walking beam heating furnace, the heating temperature is 1235 ℃, the soaking time is 98min, the total heating time is 380-448 min, and the tapping temperature is 1180-1200 ℃.
Further, the heating steps are controlled in the following sections: a preheating section: at the temperature of less than or equal to 650 ℃, and for 53-60 min; and (3) heating for a second stage: 820-940 ℃, 88-100 min; heating for a first period: 1180-1240 ℃ and 142-158 min; a soaking section: 1180-1240 ℃, 98-130 min and 1180-1200 ℃ of discharge temperature.
In the preparation method of the Cu-containing ultra-low titanium bearing steel, the rolling steps are as follows: the rolling steps are as follows: the initial rolling temperature is 1100-1200 ℃, and the final rolling temperature is 850-1000 ℃; slowly cooling rolled steel in time, wherein the pit entry temperature of the steel is more than or equal to 550 ℃, the pit exit temperature of the steel is less than or equal to 200 ℃, and the heat preservation time is more than or equal to 48 hours; performing a stack cooling process on the small bar product; putting the steel plate into a water cooling facility with the diameter less than or equal to phi 60mm, and controlling the final rolling temperature target to be 750-850 ℃.
The invention has the beneficial effects that: the invention provides a production method of Cu-containing ultra-low titanium bearing steel GCr15-CDT, which comprises the following steps: EBT electric furnace smelting → LF refining → VD vacuum degassing → continuous casting of square billet → rolling of phi 800mm bar continuous rolling mill. The method can effectively reduce the titanium content in the bearing steel, so that the bearing steel meets the quality requirement of the super-grade high-quality bearing steel, and the indexes such as inclusion content, oxygen content and the like can also meet the standard requirement. The invention has the advantages that aiming at the technical problem of titanium content in the ultra-low titanium bearing steel, the preparation method of the ultra-low titanium bearing steel GCr15-CDT is provided by reasonably selecting the process route and reasonably designing the process parameters, the purity of the steel is high, and the inclusion level is low; the titanium content can be controlled to be within 15ppm, the oxygen content can be controlled to be within 6ppm, the surface quality of the round steel is good, the quality is stable, and the requirements of domestic and foreign ultra-low titanium bearing steel customers are completely met.
Drawings
Fig. 1 is a drawing of a slag salvaging pan.
Detailed Description
The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.
The test methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
In order to meet the production requirement of super-grade high-quality bearing steel, the invention aims to provide a method capable of effectively reducing the titanium content in the bearing steel GCr 15-CDT.
A preparation method of Cu-containing ultra-low titanium bearing steel comprises the following process steps: EBT electric furnace smelting → LF refining → VD vacuum degassing → continuous casting of square billet → rolling of phi 800mm bar continuous rolling mill.
Smelting molten steel by an EBT electric arc furnace, refining molten steel by an LF ladle refining furnace, refining molten steel by a VD vacuum degassing furnace, continuously casting a 235mm multiplied by 265mm square billet, heating and rolling, wherein the molten steel in the steps comprises the following components in percentage by mass: 0.80 to 1.20%, Si: 0.10 to 2.00%, Mn: 0.20-2.50%, P: less than or equal to 0.020%, S: less than or equal to 0.012 percent, Cr: 1.20 to 2.50%, Mo: less than or equal to 0.08 percent, Al: less than or equal to 0.05 percent, Cu: 0.25 to 0.50%, Ni: less than or equal to 0.20 percent, O: less than or equal to 0.0006 percent, Ti: less than or equal to 0.0015%, Ca: less than or equal to 0.0010%, Pb: less than or equal to 0.002%, Sb: less than or equal to 0.005%, Sn: less than or equal to 0.03%, As: less than or equal to 0.04 percent, and the balance of iron and inevitable impurities.
The method comprises the following specific steps:
1. EBT electric furnace smelting
The whole smelting process does not allow the use of calcium or calcium alloy as a deoxidizer. Titanium pollution is prevented in the whole smelting process, direct production after the titanium-containing steel is not allowed, production is discharged after the bearing steel casting process with Ti less than or equal to 50ppm, and the upper casting bearing steel ladle is used as a ladle.
The method comprises the following steps of (1) taking scrap steel and molten iron as furnace burden, wherein the scrap steel is high-quality scrap steel without impurity elements, the proportion is 15-35%, and the molten iron is low-phosphorus and low-sulfur molten iron, and the proportion is 65-85%; the amount of the prepared C is more than or equal to 1.10 percent, the oxidation temperature is 1555-1585 ℃, the decarburization weight is more than or equal to 0.30 percent, the tapping requirement is met, the C is less than or equal to 0.010 percent (ensuring that steel contains a certain amount of oxygen and can remove titanium in the alloy during alloying), the P is less than or equal to 0.010 percent, other residual elements are qualified, the temperature is 1635-1650 ℃, and a pre-deoxidizer (low-carbon ferrosilicon 50kg), a carburant, ferroalloy (low-titanium high-chromium, medium-manganese, waste copper), slag materials (active lime, alumina powder) and the like are added during the tapping of 1/4-1/3.
2. LF refining
Electrifying to melt slag for 10min after the slag is melted, carrying out slag fishing operation after the slag is melted, fishing out oxidized slag in the process of electric furnace steel tapping by adopting a slag pan to fish the slag, reducing the content of titanium dioxide in the slag and reducing titanium, then feeding an Al wire for 0.5-1.5kg/t, adjusting Al in steel to 0.02-0.04%, controlling the Al to be less than or equal to 0.050% in the whole LF process, adding 1-3 kg/t of a diffusion deoxidizer in the first batch for diffusion deoxidation, closing a furnace door for 10min, adding the second batch, wherein the total addition amount is 2-4 kg/t, and taking a sample when the temperature is white; the Ca-containing deoxidizer is not allowed to be used in the whole refining process. And continuously diffusing and deoxidizing after full analysis, keeping the reducing atmosphere to the ladle, and keeping the white slag for not less than 25 min. After the deoxidation is good, the roasted low-titanium high-chromium, medium-manganese, low-carbon ferrosilicon and other alloys are added according to the component target control, and the components are adjusted to the target. The argon pressure is controlled to be 0.2-0.3 MPa in the whole process, and secondary oxidation caused by exposure of molten steel is prevented on the basis of fluctuation of slag surface and no exposure of molten steel.
3. VD refining
The VD temperature is 1570-1610 ℃, and Al is adjusted to 0.025-0.035% before VD is added, so that the finished product Al is ensured to reach 0.015-0.025%. The vacuum degree reaches below 100Pa, and the holding time is more than or equal to 20 min. And after wire feeding, the static argon blowing time is more than or equal to 25min, the argon pressure is 0.1-0.3 MPa, and secondary oxidation is prevented on the basis of micro-motion of slag surfaces and no exposure of molten steel. The temperature of the crane ladle is controlled to be 1525-1545 ℃.
4. Continuous casting
The temperature of a first furnace of the big ladle is 1525-1535 ℃, the temperature of continuous casting is 1505-1515 ℃, the temperature of a tundish is 1470-1475 ℃, the pulling speed is 0.75m/min, the specific water amount of secondary cooling water is 0.25L/kg, the electromagnetic stirring current of the crystallizer is 450A, the electromagnetic stirring current of the tail end is 330A, and the frequency is 8 Hz. The whole process of protective casting is strictly executed, and the crystallizer protective slag uses special high-carbon steel protective slag. The heat preservation time of the casting blank is more than or equal to 30 h.
5. Heating and rolling
The heating is carried out by adopting a heat accumulating type walking beam heating furnace, the heating temperature is 1235 ℃, the soaking time is 98min, and the total heating time is 380-448 min. The tapping temperature is 1180-1200 ℃.
The specific heating process is as follows.
Preheating section Heating two stage Heating one section Soaking section Discharging from the furnace
Temperature, C ≤650 820～940 1180～1240 1180～1240 1180～1200
Time, min 53～60 88～100 142～158 98～130
The rolling is carried out by adopting an 800 blooming mill and a 650 finishing mill. Wherein the initial rolling temperature is 1100-1200 ℃, the final rolling temperature is 850-1000 ℃, and the rolled steel is required to be slowly cooled in time. The pit entry temperature of the steel is more than or equal to 550 ℃, the pit exit temperature is less than or equal to 200 ℃, and the heat preservation time is more than or equal to 48 hours; the small bar product is subjected to a heap cooling process. Throwing the steel plate into a through water cooling facility with the diameter of less than or equal to phi 60mm, and controlling the final rolling temperature at 750-850 ℃.
Example 1
A preparation method of Cu-containing ultra-low titanium bearing steel comprises the following process steps: smelting molten steel by an EBT electric arc furnace, refining molten steel by an LF ladle refining furnace, refining molten steel by a VD vacuum degassing furnace, continuously casting a 235mm multiplied by 265mm square billet, heating and rolling.
The actual production steps for manufacturing the Cu-containing ultra-low titanium bearing steel GCr15-CDT steel by adopting the technical scheme of the invention are as follows:
1) EBT electric furnace smelting
The material is prepared by mixing 38t molten iron and 15t scrap steel; blowing oxygen into molten steel through a supersonic speed oxygen lance to remove C, boiling violently and flowing slag automatically, wherein the oxidation temperature is 1580 ℃, C is 0.05 percent when tapping, P is 0.006 percent, other residual elements are qualified, the temperature is 1645 ℃, and a pre-deoxidizer, namely low-carbon ferrosilicon, 50kg, carburant, ferroalloy (low-titanium high-chromium, medium-manganese, 120kg and waste copper) and slag materials (active lime, 300kg and alumina powder, 50kg) are added when tapping 1/4.
2) LF refining
Electrifying for slagging for 10min after entering the station, fishing the slag after slagging, fishing the oxidized slag in the electric furnace tapping process by using a slag pan for fishing the slag, and fishing 3 pans of slag. Then feeding 100 meters of Al wire, adjusting Al in the steel to 0.035%, controlling Al to be less than or equal to 0.050% in the whole LF process, adding 105kg of diffusion deoxidizer in the first batch for diffusion deoxidation, closing a furnace door for 10min, adding the second batch with the total addition of 120kg, and taking a sample when the temperature is in accordance with the requirement after slag is white; and continuously diffusing and deoxidizing after full analysis, keeping the reducing atmosphere to the ladle, and keeping the white slag for 28 min. After the deoxidation is good, the roasted low-titanium high-chromium, medium-manganese and low-carbon ferrosilicon alloy is added according to the component target control, and the components are adjusted to the target. The argon pressure is controlled to be 0.2-0.3 MPa in the whole process, and secondary oxidation caused by exposure of molten steel is prevented on the basis of fluctuation of slag surface and no exposure of molten steel. The ladle temperature is 1590 ℃.
3) VD degassing treatment
The VD temperature is 1585 ℃, and the Al content is 0.035%. The vacuum degree reaches below 100Pa, and the holding time is 25 min. And after wire feeding, the static argon blowing time is 28min, the argon pressure is 0.25MPa, and secondary oxidation is prevented on the basis of micro movement of the slag surface and no exposure of molten steel. The temperature of the bale was 1520 ℃.
4) Continuous casting
The temperature of a platform of the large ladle is 1515 ℃, the temperature of a tundish is 1474 ℃, 1472 ℃ and 1473 ℃, the pulling speed is 0.75m/min, the specific water amount of secondary cooling water is 0.25L/kg, the electromagnetic stirring current of the crystallizer is 450A, the electromagnetic stirring current of the tail end is 330A, and the frequency is 8 Hz. The whole process of protective casting is strictly executed, and the crystallizer protective slag uses special high-carbon steel protective slag. And keeping the temperature of the casting blank for 35 h.
5) Heating and rolling
The heating is carried out by adopting a heat accumulating type walking beam heating furnace, the heating temperature is 1235 ℃, the soaking time is 98min, and the total heating time is 420 min. The tapping temperature is 1190 ℃. The specific process comprises the following steps:
preheating section Heating two stage Heating one section Soaking zone Discharging from the furnace
Temperature, C ≤650 820～940 1180～1240 1180～1240 1190
Time, min 55 95 148 122
The rolling adopts an 800 blooming mill and a 650 finishing mill group. Wherein the initial rolling temperature is 1120 ℃, the final rolling temperature is 950 ℃, and the rolled steel is slowly cooled in time. The pit entry temperature of the steel is more than or equal to 550 ℃, the pit exit temperature is less than or equal to 200 ℃, and the heat preservation time is more than or equal to 48 hours;
6) quality of the product
Chemical composition (mass% /)
C Si Mn P S Cu Alt Cr Ni
0.97 0.22 0.31 0.017 0.002 0.30 0.018 1.46 0.02
Mo Sb Sn As Pb Bi O Ti Ca
0.01 0.0001 0.0014 0.0010 0.0014 0.0001 0.0005 0.0012 0.0005
The product has the characteristics that the A, B types are all 0.5 grade, the C, D, Ds types are all 0 grade, and the purity is higher.
The production method of the copper-containing ultralow-titanium bearing steel provided by the invention can control the content of Ti element in the copper-containing bearing steel GCr15-CDT to be 0.0012% and the content of oxygen to be 0.0005%, and has higher purity at the same time.

Claims (9)

1. A preparation method of Cu-containing ultra-low titanium bearing steel is characterized by comprising the following steps: in the method, the molten steel components are controlled, and the method comprises the following steps of:
c: 0.80-1.20%, Si: 0.10 to 2.00%, Mn: 0.20-2.50%, P: less than or equal to 0.020%, S: less than or equal to 0.012 percent, Cr: 1.20 to 2.50%, Mo: less than or equal to 0.08 percent, Al: less than or equal to 0.05 percent, Cu: 0.25 to 0.50%, Ni: less than or equal to 0.20 percent, O: less than or equal to 0.0006 percent, Ti: less than or equal to 0.0015 percent, Ca: less than or equal to 0.0010%, Pb: less than or equal to 0.002%, Sb: less than or equal to 0.005%, Sn: less than or equal to 0.03%, As: less than or equal to 0.04 percent, and the balance of iron and inevitable impurities.
2. The method of claim 1, wherein: the method comprises the following process steps: the method comprises the following steps of smelting molten steel by an EBT electric arc furnace, refining molten steel by an LF ladle refining furnace, refining molten steel by a VD vacuum degassing furnace, continuously casting a square billet, heating and rolling, wherein the step of smelting the molten steel by the EBT electric arc furnace comprises the following steps: scrap steel and molten iron are used as furnace burden, the proportion of the scrap steel is 15-35%, and the proportion of the molten iron is 65-85%; the content of the added C is more than or equal to 1.10 percent, the oxygen is oxidized, the mixture is boiled violently and flows slag automatically, the oxidation temperature is 1555-1585 ℃, the decarburization weight is more than or equal to 0.30 percent, and the steel tapping requirement is as follows: the content of C is less than or equal to 0.10%, the content of P is less than or equal to 0.010%, other residual elements are qualified, the temperature is 1635-1650 ℃, an oxidation method is adopted for alloy titanium removal treatment in the tapping process, namely, oxygen in steel is used for oxidizing and removing titanium in the alloy so as to achieve the purpose of ultra-low titanium content, the alloy is added in the following sequence, 8-15 kg/t of low-titanium high-chromium and 10-35 kg/t of medium manganese are firstly added during tapping 1/4-1/3, and then 5-20 kg/t of low-carbon ferrosilicon, 8-10 kg/t of low-titanium carburant, 4-6 kg/t of active lime and 2-4 kg/t of alumina powder are added.
3. The method of claim 2, wherein: the scrap steel is high-quality scrap steel without impurity elements; the molten iron is low-phosphorus and low-sulfur molten iron.
4. The method of claim 2, wherein: the LF ladle refining furnace is used for refining molten steel and comprises the following steps: deslagging, namely removing oxidizing slag generated in the tapping process of the electric furnace by deslagging through a slag pan so as to remove titanium dioxide in the slag and reduce titanium dioxide which is reduced into titanium in the refining process and enters molten steel, so that the titanium content of the molten steel is increased; slagging, namely adjusting Al in steel to 0.020-0.040%, controlling Al to be less than or equal to 0.050% in the whole LF process, adding 1-3 kg/t of a diffusion deoxidizer ferrosilicon powder into the first batch for diffusion deoxidation, closing a furnace door for 10min, adding the second batch, wherein the total addition is 2-4 kg/t, and taking a primary sample after the slag is white according with the requirement; ca-containing deoxidizer is not allowed to be used in the whole refining process; continuously diffusing and deoxidizing after full analysis, keeping the reducing atmosphere to the ladle, and keeping the white slag for not less than 25 min; after the deoxidation is good, adding the baked low-titanium high-chromium, medium-manganese, low-carbon ferrosilicon and waste copper alloy according to the component target control, adjusting the components to the target, and controlling the argon pressure to be 0.2-0.3 MPa in the whole process.
5. The method of claim 2, wherein: the molten steel refining step of the VD vacuum degassing furnace comprises the following steps: the VD temperature is 1570-1610 ℃, Al is adjusted to 0.025-0.035% before VD, so that the finished product Al is ensured to reach 0.015-0.025%, the vacuum degree is below 100Pa, and the holding time is more than or equal to 20 min; after vacuum treatment, the static argon blowing time is more than or equal to 25min, the argon pressure is 0.1-0.3 MPa, and the bag temperature is controlled at 1525-1545 ℃.
6. The method of claim 2, wherein: the continuous casting of the square billet comprises the following steps: the temperature of a first furnace of the big ladle is 1525-1535 ℃, the temperature of continuous casting is 1505-1515 ℃, the temperature of a tundish is 1470-1475 ℃, the pulling speed is 0.75m/min, the specific water amount of secondary cooling water is 0.25L/kg, the electromagnetic stirring current of a crystallizer is 450A, the electromagnetic stirring current of the tail end is 330A, and the frequency is 8 Hz; the whole process is strictly carried out for casting protection, high-carbon steel casting powder is used as the crystallizer casting powder, and the casting blank heat preservation time is more than or equal to 30 h.
7. The method of claim 2, wherein: the heating step is as follows: the heating is carried out by adopting a heat accumulating type walking beam heating furnace, the heating temperature is 1235 ℃, the soaking time is 98min, the total heating time is 380-448 min, and the tapping temperature is 1180-1200 ℃.
8. The method of claim 7, wherein: the heating steps are controlled as follows: a preheating section: at the temperature of less than or equal to 650 ℃, for 53-60 min; and (3) heating for a second stage: 820-940 ℃, 88-100 min; heating for a first period: 1180-1240 ℃ and 142-158 min; a soaking section: 1180-1240 ℃, 98-130 min and 1180-1200 ℃ of discharge temperature.
9. The method of claim 2, wherein: the rolling steps are as follows: the initial rolling temperature is 1100-1200 ℃, and the final rolling temperature is 850-1000 ℃; slowly cooling rolled steel in time, wherein the pit entry temperature of the steel is more than or equal to 550 ℃, the pit exit temperature of the steel is less than or equal to 200 ℃, and the heat preservation time is more than or equal to 48 hours; performing a stack cooling process on the small bar product; putting the steel plate into a water cooling facility with the diameter less than or equal to phi 60mm, and controlling the final rolling temperature target to be 750-850 ℃.
CN202210487708.9A 2022-05-06 2022-05-06 Preparation method of Cu-containing ultralow-titanium bearing steel Pending CN115011871A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116790961A (en) * 2023-05-31 2023-09-22 本钢板材股份有限公司 Method for smelting bearing steel by adopting full scrap steel based on ecological electric furnace
CN116790962A (en) * 2023-05-31 2023-09-22 本钢板材股份有限公司 High-carbon steel tapping production process of high-purity bearing steel electric furnace
CN116815048A (en) * 2023-03-31 2023-09-29 本钢板材股份有限公司 Alloy structural steel for railway axle and preparation method thereof
CN117051323A (en) * 2023-08-10 2023-11-14 南京钢铁股份有限公司 High-standard bearing hot-rolled narrow strip steel and preparation method thereof

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101397628A (en) * 2007-09-25 2009-04-01 宝山钢铁股份有限公司 Continuous casting bearing steel round steel and method for producing the same
CN102352466A (en) * 2011-11-02 2012-02-15 承德建龙特殊钢有限公司 High-carbon chromium bearing steel GCr15 and production method thereof
US20140261906A1 (en) * 2011-10-20 2014-09-18 Nippon Steel & Sumitomo Metal Corporation Bearing steel and method for producing same
CN106148844A (en) * 2016-08-12 2016-11-23 常州东大中天钢铁研究院有限公司 A kind of preparation method of sulfur-bearing ultralow titanium high standard bearing steel
WO2018214863A1 (en) * 2017-05-26 2018-11-29 宝山钢铁股份有限公司 Bearing steel for use in automobile wheels and manufacturing process therefor
CN110527909A (en) * 2019-09-11 2019-12-03 本钢板材股份有限公司 A kind of preparation method of the beating steel GCr15 of ultralow titanium containing Cu-J
CN112662833A (en) * 2020-11-18 2021-04-16 邯郸钢铁集团有限责任公司 Smelting method of low-cost high-carbon chromium bearing steel
CN114058970A (en) * 2021-11-22 2022-02-18 北京科技大学 Production method of bearing steel

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101397628A (en) * 2007-09-25 2009-04-01 宝山钢铁股份有限公司 Continuous casting bearing steel round steel and method for producing the same
US20140261906A1 (en) * 2011-10-20 2014-09-18 Nippon Steel & Sumitomo Metal Corporation Bearing steel and method for producing same
CN102352466A (en) * 2011-11-02 2012-02-15 承德建龙特殊钢有限公司 High-carbon chromium bearing steel GCr15 and production method thereof
CN106148844A (en) * 2016-08-12 2016-11-23 常州东大中天钢铁研究院有限公司 A kind of preparation method of sulfur-bearing ultralow titanium high standard bearing steel
WO2018214863A1 (en) * 2017-05-26 2018-11-29 宝山钢铁股份有限公司 Bearing steel for use in automobile wheels and manufacturing process therefor
CN110527909A (en) * 2019-09-11 2019-12-03 本钢板材股份有限公司 A kind of preparation method of the beating steel GCr15 of ultralow titanium containing Cu-J
CN112662833A (en) * 2020-11-18 2021-04-16 邯郸钢铁集团有限责任公司 Smelting method of low-cost high-carbon chromium bearing steel
CN114058970A (en) * 2021-11-22 2022-02-18 北京科技大学 Production method of bearing steel

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116815048A (en) * 2023-03-31 2023-09-29 本钢板材股份有限公司 Alloy structural steel for railway axle and preparation method thereof
CN116790961A (en) * 2023-05-31 2023-09-22 本钢板材股份有限公司 Method for smelting bearing steel by adopting full scrap steel based on ecological electric furnace
CN116790962A (en) * 2023-05-31 2023-09-22 本钢板材股份有限公司 High-carbon steel tapping production process of high-purity bearing steel electric furnace
CN117051323A (en) * 2023-08-10 2023-11-14 南京钢铁股份有限公司 High-standard bearing hot-rolled narrow strip steel and preparation method thereof

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