G0Cr13Co5Ni3Mo2V stainless bearing steel, stainless bearing steel bar and preparation method thereof

Abstract

The invention relates to G0Cr13Co5Ni3Mo2V stainless bearing steel, a stainless bearing steel bar and a preparation method of the stainless bearing steel bar, and relates to the technical field of aviation bearing steel preparation. According to the main technical scheme, the stainless bearing steel comprises the following chemical components in percentage by weight: 0.05-0.12 wt% of C; si: 0.1 to 0.6 wt%; mn: 0.5 to 1.0 wt%; p is less than or equal to 0.01 wt%; s < = 0.002 wt%; cr: 12 to 16.5 wt%; ni: 2.0 to 3.0 wt%; co: 4.0 to 7.0 wt%; mo: 1.2 to 2.7 wt%; 0.4 to 0.8 weight percent of V; w < = 0.5 wt%; nb is less than or equal to 0.05 wt%; al: 0.02 to 0.05 wt%; and the balance of Fe. The method is mainly used for preparing the high-quality G0Cr13Co5Ni3Mo2V stainless bearing steel bar so as to meet the service performance requirements of a long-life bearing under the harsh working conditions of corrosion resistance, high speed, high temperature (315-500 DEG C) and large load.

Description

Technical Field

[0001] This invention relates to the field of aerospace bearing steel preparation technology, and in particular to a G0Cr13Co5Ni3Mo2V stainless bearing steel, stainless bearing steel bars and their preparation methods. Background Technology

[0002] G0Cr13Co5Ni3Mo2V, a key bearing steel for aerospace applications, exhibits excellent high-temperature stability, wear resistance, and corrosion resistance after carburizing. This steel can replace AMS 5930 standard and imported Pyrowear 675 bearing steel.

[0003] To meet the demands of high-speed, high-temperature, and high-load operating conditions, as well as long fatigue life performance, high-quality bar stock is manufactured using vacuum induction melting combined with vacuum arc remelting and forging combined with rolling hot deformation. As is well known, aerospace bearings have extremely high requirements for reliability and lifespan consistency; high-quality bar stock is a crucial guarantee for high-quality bearings.

[0004] Research on aerospace bearing steel started relatively late. Currently, there is very little research on aerospace bearing steel that can meet the requirements of high-temperature stability, wear resistance, and good corrosion resistance. Similarly, there is a lack of research on the preparation process of high-quality bars. Therefore, it is urgent to systematically develop a preparation method for high-quality G0Cr13Co5Ni3Mo2V stainless bearing steel, solve the quality problems of existing bars, and help to achieve the preparation of an aerospace bearing steel with high-temperature stability, wear resistance, and corrosion resistance. Summary of the Invention

[0005] In view of this, the present invention provides G0Cr13Co5Ni3Mo2V stainless bearing steel, stainless bearing steel bars and their preparation methods, the main purpose of which is to improve the high-temperature stability, wear resistance and corrosion resistance of stainless steel bearing bars.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions: On one hand, embodiments of the present invention provide a G0Cr13Co5Ni3Mo2V stainless bearing steel, wherein, by weight percentage, the stainless bearing steel comprises the following chemical composition: C: 0.05-0.12wt%; Si: 0.1-0.6wt%; Mn: 0.5-1.0wt%; P≤0.01wt%; S≤0.002wt%; Cr: 12-16.5wt%; Ni: 2.0-3.0wt%; Co: 4.0-7.0wt%; Mo: 1.2-2.7wt%; V: 0.4-0.8wt%; W≤0.5wt%; Nb≤0.05wt%; Al: 0.02-0.05wt%; balance Fe; Preferably, in the stainless bearing steel, the weight percentage of Cr is 13-13.5 wt%. Preferably, in the stainless bearing steel, the sum of the weight percentages of V, W and Nb elements is ≤0.8%.

[0007] Preferably, the stainless bearing steel bar is made from the aforementioned stainless bearing steel.

[0008] Preferably, in the stainless bearing steel bar: δ-ferrite content ≤ 1%, maximum carbide size ≤ 2 μm, TO ≤ 6 ppm, inclusion size < 10 μm, and inclusion density ≤ 4 inclusions / mm². 2 ; and / or the grain size of the stainless bearing steel bar is ≥ grade 5; preferably, the maximum size of the carbides in the stainless bearing steel bar is ≤ 0.5 μm, and preferably, the carbides are uniformly distributed; and / or the room temperature Charpy V-notch impact energy of the stainless bearing steel bar after quenching, cryogenic treatment, and multiple tempering treatments is ≥ 100 J; wherein, the quenching temperature is 1020-1050℃; the cryogenic treatment temperature is ≤ -73℃; the tempering temperature is 300-500℃; preferably, the number of tempering treatments is ≥ 2 times.

[0009] Preferably, the stainless bearing steel bar, after surface carbonitriding treatment, meets the acid corrosion resistance test at pH=3.5; and / or the stainless bearing steel bar, after surface strengthening treatment, has a surface hardness ≥60HRC at room temperature and a surface hardness ≥58HRC at 400℃.

[0010] On the other hand, the method for preparing G0Cr13Co5Ni3Mo2V stainless bearing steel bars according to any one of the above claims of the present invention includes the following steps: Preparation of consumable ingots: The raw materials are subjected to vacuum induction melting and refining to obtain electrode blanks; the electrode blanks are subjected to vacuum consumable treatment to prepare consumable ingots that meet the set requirements. High-temperature homogenization treatment: The consumable ingot is subjected to high-temperature homogenization treatment to obtain a steel ingot after high-temperature homogenization treatment; Hot deformation treatment: The steel ingot after the high temperature homogenization treatment is subjected to hot deformation treatment to obtain hot-deformed bar stock; First annealing treatment: The hot-deformed bar is subjected to a first annealing treatment to obtain stainless bearing steel bar.

[0011] Preferably, in the step of preparing consumable ingots: during the vacuum induction melting and refining process of the raw materials: the raw materials are first melted into molten metal, and then subjected to low-temperature vacuum carbon deoxidation. The vacuum carbon deoxidation time is 30-50 minutes, the temperature is 1500-1550°C, and the vacuum degree is controlled at ≤50Pa to ensure that TO in the molten metal is ≤20ppm. Then, in the refining stage, an alloy including Si and Mn elements is added to adjust the composition of the molten metal. Then, Al elements are added to the molten metal for Al deoxidation. The refining stirring time during Al deoxidation is controlled at 30-50 minutes to reduce dissolved oxygen in the molten metal and allow inclusions to float fully. Finally, rare earth elements (RE) are added to the molten metal for final deoxidation. Oxygen, wherein the refining stirring time during final deoxidation is controlled at 30-50 min, and the operating temperature is controlled below 1600℃; finally, casting is performed to obtain an electrode billet with TO≤10ppm; preferably, the amount of Al added is 0.02-0.05wt% of the metal liquid mass; rare earth RE is a composite rare earth of Ce and La; preferably, the amount of rare earth RE added is 0.01-0.03wt% of the metal liquid; and / or during the vacuum consumable treatment, the ratio of the center depth of the molten pool to the diameter of the consumable ingot is controlled at 0.55-0.65 to promote the flotation of inclusions; and / or the consumable ingot meets the following requirements: TO≤6ppm, S≤0.002wt%, P≤0.006wt%, Ti≤0.0020wt%.

[0012] Preferably, before the high-temperature homogenization treatment step, the method further includes: sequentially performing a second annealing treatment and a surface peeling treatment on the consumable ingot; preferably, the second annealing treatment includes: first holding the consumable ingot at a temperature of 800-850℃ for 1.5-2.5h / 25mm, then lowering the temperature to 700-750℃, and then holding the consumable ingot at this temperature for 1-2h / 25mm.

[0013] Preferably, in the high-temperature homogenization treatment step: the consumable ingot is heated, and the consumable ingot is first held at a temperature of 500-600℃, then held at a temperature of 800-1000℃ for a second time, and then heated to 1160-1250℃ for high-temperature homogenization diffusion treatment; preferably, the high-temperature homogenization diffusion treatment time is ≥20h; preferably, the first holding time is 2-6h; preferably, the second holding time is 2-6h; preferably, after the second holding time and before the high-temperature homogenization diffusion treatment, the method further includes: pre-deformation treatment of the consumable ingot to promote δ-ferrite transformation and carbide dissolution; preferably, the pre-deformation treatment includes: first holding the consumable ingot at 1130-1150℃, and then upsetting and drawing; wherein, the forging ratio is ≥2.

[0014] Preferably, in the heat deformation treatment step: The hot deformation treatment steps include: forging the steel ingot after high-temperature homogenization treatment to obtain a hot-deformed bar with a grain size ≥ 5, a δ-ferrite content ≤ 1%, and a diameter of 90-130 mm; or, forging the steel ingot after high-temperature homogenization treatment to obtain a square bar; and then rolling the square bar to obtain a hot-deformed bar with a grain size ≥ 5, a δ-ferrite content ≤ 1%, and a diameter of less than 90 mm. Preferably, the forging process includes: employing at least two upsetting and drawing operations; preferably, the forging ratio for each operation is ≥2 and the total forging ratio is ≥8; preferably, during each drawing operation, a symmetrical pressing method is used to ensure that the center position of the steel ingot does not shift. Preferably, the forging temperature during the deformation process is not lower than 950°C; Preferably, the bar stock is cooled after the heat deformation treatment. More preferably, the first annealing treatment is performed after the bar stock temperature is ≤300℃.

[0015] Preferably, in the first annealing step: After the hot-deformed bar undergoes a first annealing treatment, the maximum size of carbides in the resulting stainless bearing steel bar is ≤2μm; and / or The first annealing treatment includes: first holding the heat-deformed bar at a temperature of 640-750℃ for 1.5-2.5h / 25mm.

[0016] Compared with the prior art, the G0Cr13Co5Ni3Mo2V stainless steel bearing bar and its preparation method of the present invention have at least the following beneficial effects: On one hand, embodiments of the present invention provide a G0Cr13Co5Ni3Mo2V stainless bearing steel, wherein, by weight percentage, the stainless bearing steel comprises the following chemical composition: C: 0.05-0.12wt%; Si: 0.1-0.6wt%; Mn: 0.5-1.0wt%; P≤0.01wt%; S≤0.002wt%; Cr: 12-16.5wt%; Ni: 2.0-3.0wt%; Co: 4.0-7.0wt%; Mo: 1.2-2.7wt%; V: 0.4-0.8wt%; W≤0.5wt%; Nb≤0.05wt%; Al: 0.02-0.05wt%; the balance being Fe. The chemical composition described above is explained as follows: This invention, for the first time, selects Cr element with a content of 12 wt% or more, and rationally matches C, Mo, V, W, and Nb to obtain finely dispersed carbides. This gives the stainless bearing steel matrix excellent corrosion resistance. Even after surface strengthening treatments such as carbonitriding, the surface carbides remain dispersed, with grain boundary carbides <5 μm. The surface nitrogen content increases, yet good corrosion resistance is still maintained. This invention, by adding Co, an element that promotes carbide dispersion and precipitation, and Mo, V, W, and Nb, which stabilize carbides at high temperatures, combined with surface strengthening treatments such as carbonitriding, enables the stainless bearing steel to have a service temperature >315℃ and excellent high-temperature stability, superior to the commonly used M50 and M50NiL bearing steels. Furthermore, in the stainless bearing steel: the weight percentage of Cr element is 13-13.5 wt%; the sum of the weight percentages of V, W, and Nb elements is ≤0.8%, to meet the comprehensive control requirements for corrosion resistance and grain size.

[0017] On the other hand, embodiments of the present invention provide a method for preparing G0Cr13Co5Ni3Mo2V stainless bearing steel bars. These stainless bearing steel bars are prepared from the aforementioned stainless bearing steel and mainly include the following steps: preparing consumable ingots that meet set requirements; subjecting the consumable ingots to high-temperature homogenization treatment to obtain high-temperature homogenized steel ingots; subjecting the high-temperature homogenized steel ingots to hot deformation treatment to obtain hot-deformed bars; and subjecting the hot-deformed bars to a first annealing treatment to obtain the stainless bearing steel bars. Further, based on the AC1 phase transformation point and stress reduction requirements of this steel grade, the present invention controls the temperature of the first annealing treatment to 640-750℃.

[0018] Furthermore, this invention provides a G0Cr13Co5Ni3Mo2V stainless bearing steel bar. Based on the aforementioned chemical composition and preparation method, the δ-ferrite content and carbide size in the G0Cr13Co5Ni3Mo2V stainless bearing steel bar are optimally controlled. The grain size of the G0Cr13Co5Ni3Mo2V stainless bearing steel bar is grade 5 or finer, overcoming the problem of partial mixed crystals widely present in domestically produced bars. The room temperature Charpy V-notch impact energy of the G0Cr13Co5Ni3Mo2V stainless bearing steel is ≥150J. The G0Cr13Co5Ni3Mo2V stainless bearing steel bar exhibits excellent corrosion resistance, wear resistance, and high-temperature stability. Therefore, the G0Cr13Co5Ni3Mo2V bar prepared by this invention has excellent performance, further solving the fatigue spalling problem of in-service bearings, greatly improving the service life of aerospace bearings, and contributing to the advancement of aerospace bearing manufacturing. This invention provides raw materials for the preparation of high-quality corrosion-resistant bearings in the fields of aviation and aerospace, and can replace imported P675 and similar stainless steel bars.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a microstructure diagram of a G0Cr13Co5Ni3Mo2V stainless bearing steel bar prepared in Example 1; Figure 2 This is a microstructure diagram of a G0Cr13Co5Ni3Mo2V stainless bearing steel bar prepared in Example 2; Figure 3 This is a microstructure diagram of a G0Cr13Co5Ni3Mo2V stainless bearing steel bar prepared in Example 3. Detailed Implementation

[0021] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0022] This invention provides a G0Cr13Co5Ni3Mo2V stainless bearing steel, stainless bearing steel bars, and a method for preparing the same. The main inventive concept is as follows: Firstly, the chemical composition of the G0Cr13Co5Ni3Mo2V stainless bearing steel is designed as follows: C: 0.05-0.12wt%; Si: 0.1-0.6wt%; Mn: 0.5-1.0wt%; P≤0.01wt%; S≤0.002wt%; Cr: 12-16.5wt%; Ni: 2.0-3.0wt%; Co: 4.0-7.0wt%; Mo: 1.2-2.7wt%; V: 0.4-0.8wt%; W≤0.5wt%; Nb≤0.05wt%; Al: 0.02-0.05wt%; the balance is Fe. This invention, for the first time, selects Cr element with a content of more than 12wt% and rationally matches C, Mo, V, W, and Nb to give the stainless bearing steel matrix excellent corrosion resistance, which remains good even after surface strengthening treatments such as carbonitriding. This invention, by adding Co, Mo, V, W, and Nb alloys and combining them with surface strengthening treatments such as carbonitriding, enables the stainless bearing steel to have an operating temperature >315℃ and excellent high-temperature stability, superior to the commonly used M50 and M50NiL bearing steels. Furthermore, based on the above-mentioned chemical composition of the stainless bearing steel, combined with short-time vacuum carbon deoxidation, Al refining deoxidation, rare earth deep deoxidation during vacuum induction melting and refining processes, and a self-consumable melting process with a large aspect ratio molten pool, a low-oxygen electrode billet is obtained; by utilizing large deformation and strong carbide precipitation control, the difficult-to-control target of grain size ≥5 is achieved, resulting in high-performance stainless bearing steel bars. Based on the reasonable alloying of the bar material and the combination of a reasonable carbonitriding surface treatment process, the material is endowed with high hot hardness, meeting the high performance requirement of hardness ≥58HRC at 400℃.

[0023] The preparation method of G0Cr13Co5Ni3Mo2V stainless bearing steel mainly includes the following steps: Preparation of consumable ingots: First, an electrode blank that meets the set requirements is prepared; wherein, the set requirements are as follows: the total oxygen content in the electrode blank is TO≤10ppm, S≤0.002wt%, P≤0.006wt%, and Ti≤0.0020wt%; the electrode blank is subjected to a vacuum consumable remelting process with a large aspect ratio to remove inclusions, thereby obtaining a consumable ingot; wherein, by controlling the parameters of the vacuum consumable remelting process, the consumable ingot is made to meet the following requirements: TO≤6ppm, S≤0.002wt%, P≤0.006wt%, and Ti≤0.0020wt%.

[0024] Preferably, the electrode blank is prepared by vacuum induction melting; wherein the steps of preparing the electrode blank by vacuum induction melting are as follows: A high-purity electrode blank is prepared using a vacuum induction furnace. First, high-quality iron-based raw materials (TO≤25ppm, S≤0.001%, P≤0.004%, Ti≤0.0010%), along with other alloys and carbon, are added to the vacuum induction furnace according to the lower limit of the target composition. After evacuation, the metal is then electrically heated to melt it. The impurity elements in the added alloys must meet the technical requirements of S≤0.002%, P≤0.006%, and Ti≤0.0015% in the molten metal. After the molten metal melts, vacuum carbon deoxidation is first performed for 30-50 minutes, with the temperature controlled at 1500-1550℃, the vacuum degree controlled at ≤50Pa, and TO reaching below 20ppm. Then, in the refining stage, Si, Mn, and other alloys are added to adjust the composition of the molten alloy. Afterward, Al is added for deoxidation, with the deoxidation time controlled at 30-50 minutes to significantly reduce dissolved oxygen and allow inclusions to float to the surface. Finally, rare earth elements are used for final deoxidation, with the refining stirring time controlled at 30-50 minutes and the operating temperature optimally controlled below 1600℃ (not exceeding 1600℃). The stirring operation is performed at least three times using alternating strong and weak stirring power supplies from both the stirring and melting power sources. Finally, the molten steel (metal) is poured into an tundish using a slag-blocking weir to prepare electrode billets.

[0025] Preferably, in the vacuum arc remelting step: the center depth of the molten pool and the diameter of the arc remelting ingot are controlled to be 0.55-0.65 mm, so that the arc remelting ingot meets the following requirements: TO ≤ 6 ppm, S ≤ 0.002 wt%, P ≤ 0.006 wt%, Ti ≤ 0.0020 wt%. Preferably, the center depth of the molten pool and the diameter of the arc remelting ingot are controlled to be 0.55-0.65 mm by adjusting the melting power, applying forced cooling of the crystallizer, and adding gap air cooling according to the size of the arc remelting ingot under the condition of crystallizer water cooling.

[0026] The consumable ingot prepared in this step, after its head and tail ends are removed, has a carbon content fluctuation of ≤0.04% at its cross-section.

[0027] Here, it should be noted that the present invention first achieves the preparation of high-purity electrode billets through the selection of raw materials and purification smelting in a vacuum induction furnace; on this basis, the electrode billets are subjected to vacuum consumable remelting treatment, and the oxygen content and cross-sectional carbon segregation in the consumable ingot are effectively controlled (preferably by controlling the consumable remelting parameters to control the solidification structure in the consumable ingot and obtain a low-segregation consumable ingot); wherein, TO≤6ppm, S≤0.002%, P≤0.006%, Ti≤0.0020% in the consumable ingot; the cross-sectional carbon composition fluctuation of the consumable ingot is controlled within ≤0.04%. This achieves the preparation of low-segregation, high-purity G0Cr13Co5Ni3Mo2V consumable ingots, laying a good foundation for the preparation of high-quality bearing steel bars.

[0028] High-temperature homogenization treatment: The consumable ingot is subjected to high-temperature homogenization treatment to obtain a steel ingot with δ ferrite content ≤3% and maximum carbide size ≤3μm.

[0029] Before the high-temperature homogenization treatment of the consumable ingot, the ingot needs to undergo a second annealing treatment and a surface peeling treatment sequentially. Preferably, the second annealing treatment includes: first holding the consumable ingot at a temperature of 800-850℃, and then holding it at a temperature of 700-750℃. Alternatively, the annealing treatment can be performed directly in the two temperature ranges to ensure that the surface peeling process proceeds normally.

[0030] The high-temperature homogenization treatment specifically involves heating the consumable ingot, first holding it at 500-600℃, then holding it at 800-1000℃, and finally raising the temperature to 1160-1250℃ for high-temperature homogenization diffusion treatment. Preferably, the high-temperature homogenization diffusion treatment lasts for ≥20 hours; preferably, the first holding time is 2-6 hours; preferably, the second holding time is 2-6 hours.

[0031] Preferably, after the second heat treatment and before the high-temperature homogenization and diffusion treatment, the consumable ingot is subjected to a pre-deformation treatment to increase ferrite transformation and carbide dissolution; wherein the pre-deformation treatment includes: first heat treatment of the consumable ingot at 1130-1150℃, and then roughing and drawing treatment; wherein the forging ratio is ≥2.

[0032] In this step, after the consumable ingot is subjected to high-temperature uniform treatment, the resulting G0Cr13Co5Ni3Mo2V stainless bearing steel ingot has the following characteristics: δ ferrite content ≤3% and maximum carbide ≤3μm, as observed by metallographic method.

[0033] Here, it should be noted that: based on the consumable ingot prepared in the previous step, the present invention uses a high-temperature homogenization diffusion treatment process of ≥1130℃, preferably combined with a pre-deformation process before high-temperature homogenization, to prepare a steel ingot with δ ferrite content ≤3% and maximum carbide ≤3μm.

[0034] Hot deformation treatment steps: The steel ingot after high-temperature homogenization treatment is subjected to hot deformation treatment to obtain hot-deformed bars with grain size ≥ 5 and δ ferrite content ≤ 1%.

[0035] The hot deformation treatment step includes: forging the steel ingot after high-temperature homogenization treatment to obtain a hot-deformed bar with a grain size ≥ 5, a δ ferrite content ≤ 1%, and a diameter of 90-130mm; or forging the steel ingot after high-temperature homogenization treatment to obtain a square billet; and then rolling the square billet to obtain a hot-deformed bar with a grain size ≥ 5, a δ ferrite content ≤ 1%, and a diameter of less than 90mm (the billet can be forged into a φ90-130mm round bar; or forged into a 120mm×120mm×L square billet, which can be used to roll bars with a diameter of less than φ90mm).

[0036] The forging process includes: employing at least two upsetting and drawing operations; each forging ratio ≥2 and the total forging ratio ≥8; preferably, during each drawing, a symmetrical pressing method is used to ensure that the center position of the G0Cr13Co5Ni3Mo2V stainless bearing steel ingot does not shift.

[0037] The process involves cooling after heat deformation treatment. Preferably, the first annealing treatment is performed after the bar stock temperature is ≤300℃.

[0038] Here, it should be noted that, based on the aforementioned steps of "preparing consumable ingots and hot deformation treatment", this invention has formulated a reasonable hot deformation process to ensure that the δ-ferrite content in the prepared bar is ≤1% and the maximum size of the carbides is ≤2μm. This provides raw materials for the preparation of high-quality bearings in the aerospace and aviation fields and can replace imported G0Cr13Co5Ni3Mo2V bars.

[0039] First annealing treatment: The hot-deformed bar is subjected to a first annealing treatment to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bar.

[0040] In the case of the G0Cr13Co5Ni3Mo2V stainless bearing steel bar obtained after the first annealing treatment of the hot-deformed bar, the maximum size of the carbides is ≤2μm.

[0041] The first annealing process includes: first holding the heat-deformed bar at a temperature of 640-750℃ for 1.5-2.5h / 25mm.

[0042] In summary, the present invention proposes a method for preparing G0Cr13Co5Ni3Mo2V stainless bearing steel bars. Through double-vacuum purification smelting, the prepared consumable ingot meets the following requirements: TO ≤ 6ppm, S ≤ 0.002wt%, P ≤ 0.006wt%, Ti ≤ 0.0020wt%, and the carbon composition fluctuation of the ingot cross-section is controlled to ≤ 0.04%. Based on the high-purity, low-segregation consumable ingot, it undergoes high-temperature homogenization treatment combined with hot deformation process control. Pre-deformation control can be performed before the high-temperature homogenization treatment to achieve the dissolution of carbides and reduce the content and size of δ-ferrite in the bar, resulting in a δ-ferrite content ≤ 0.1%, a maximum carbide size ≤ 2μm, a grain size of grade 5 or finer, TO ≤ 6ppm, inclusion size < 10μm, and an inclusion number density ≤ 4 inclusions / mm². 2 The G0Cr13Co5Ni3Mo2V stainless bearing steel bar prepared by this invention, after performance heat treatment, exhibits a V-notch impact energy ≥100J. Furthermore, the steel demonstrates excellent corrosion resistance after carbon and nitrogen treatment of the matrix, meeting the requirements of a pH=3.5 acidic test. After surface strengthening treatment, the surface hardness is ≥60HRC at room temperature and ≥58HRC at 400℃. This invention achieves the preparation of high-quality, high-temperature resistant, and corrosion-resistant aerospace bearing steel bars, meeting the performance requirements of long-life bearings under harsh conditions of high speed, high temperature, and high load.

[0043] The present invention will be further illustrated below through specific experimental examples: Example 1 This embodiment prepares a G0Cr13Co5Ni3Mo2V stainless bearing steel bar, and the main steps are as follows: 1) Preparation of consumable ingots: First, a high-purity electrode blank is prepared; the high-purity electrode blank is then subjected to vacuum consumable remelting to obtain consumable ingots. The chemical composition of the consumable ingots, by weight percentage, is as follows: C: 0.06wt%; Si: 0.3wt%; Mn: 0.55wt%; P: 0.005wt%; S: 0.0012wt%; Cr: 12.7wt%; Ni: 2.3wt%; Co: 5.5wt%; Mo: 1.8wt%; V: 0.55wt%; W≤0.03wt%; Nb≤0.02wt%; Al: 0.035wt%, with the balance being Fe. The specific steps are as follows: Preparation of high-purity electrode blanks: Electrode blanks are prepared by vacuum induction melting. First, high-quality iron-based raw materials (meeting the following conditions: TO=20ppm, S=0.0008wt%, P=0.003wt%, Ti=0.0008wt%), along with other alloys and carbon, are added to a vacuum induction furnace according to the lower limit of the target composition. After vacuuming, the metal is then electrically heated to melt it. The impurity elements in the added alloys must meet the high-purity technical requirements of S≤0.0010wt%, P≤0.0060wt%, and Ti≤0.0010wt% in the electrode blank. After melting, the molten metal undergoes vacuum carbon deoxidation treatment within a melting temperature range of 1500-1550℃ to control TO at 15ppm. Then, the composition of the alloy liquid is adjusted. Subsequently, Al deoxidation was performed during the refining stage. The optimal refining stirring time for the final deoxidation was controlled at 35 minutes. Then, rare earth elements (0.025 wt% of the molten metal) were added for final deoxidation. The optimal operating temperature was controlled at 1600℃, and the stirring was performed three times with alternating strong and weak stirring. Finally, the molten steel (metal) was poured into an tundish using a slag-blocking weir to prepare the electrode billet. The Al content in the electrode billet was controlled at 0.035 wt%.

[0044] Preparation of consumable ingots: The electrode blanks after vacuum induction melting are subjected to vacuum consumable remelting to prepare consumable ingots. Specifically, the electrode blanks are subjected to vacuum consumable remelting; during the vacuum consumable remelting process, the melting power is adjusted and forced cooling of the crystallizer is applied. Under water-cooled crystallizer conditions, gap air cooling is added to control the depth / width ratio of the molten pool ("depth" refers to the center depth of the molten pool; "width" refers to the diameter of the consumable ingot) to be 0.65. The consumable ingots meet the following requirements: O ≤ 6 ppm, S ≤ 0.002 wt%, P ≤ 0.006 wt%, Ti ≤ 0.0020 wt%.

[0045] After the head and tail ends of the consumable ingot are removed, the cross-sectional carbon composition fluctuation of the consumable ingot is controlled to ≤0.04%, and there is no point segregation in the cross-section of the consumable ingot at low magnification.

[0046] The consumable ingot is subjected to a second annealing treatment and a surface peeling treatment in sequence. The second annealing treatment includes: first holding the consumable ingot at a temperature of 850℃ for 2 hours / 25mm, then lowering the temperature to 720℃ and holding the consumable ingot at this temperature for 1.5 hours / 25mm.

[0047] 2) High-temperature homogenization treatment: The consumable ingot is heated, first held at 600℃ for 5 hours, then held at 800℃ for 5 hours. Next, the temperature is raised to 1140±10℃ for pre-deformation, where the forging ratio is ≥2. Finally, a high-temperature homogenization diffusion treatment is performed at 1180℃ for 30 hours.

[0048] Among them, the steel ingot obtained after high-temperature homogenization treatment of the consumable ingot has the following characteristics: the δ ferrite content is ≤3% and the maximum size of carbides is ≤3μm, as observed by metallographic method.

[0049] 3) Hot deformation treatment steps: The steel ingot after high temperature homogenization treatment is forged and rolled (forged into 120mm×120mm×L square material, and further rolled into bars with a diameter of less than φ90mm) to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bars.

[0050] To obtain a 70mm diameter bar, two upsetting and drawing operations were used during the forging process; the total forging ratio was 12; and a symmetrical pressing method was used during each drawing to ensure that the center position of the ingot did not shift. The forging temperature during the deformation process was not lower than 950℃.

[0051] 4) First annealing treatment: G0Cr13Co5Ni3Mo2V stainless bearing steel bars were obtained after heat treatment at 640℃ (heat treatment time was 2h / 25mm).

[0052] See Figure 1 In this embodiment, the δ-ferrite content of the G0Cr13Co5Ni3Mo2V stainless bearing steel bar is ≤1%, the maximum carbide size is ≤2μm, and the grain size of the bar is grade 6.5; furthermore, the bar contains: TO=6ppm, inclusion size <8μm, and inclusion number density ≤3 inclusions / mm. 2 .

[0053] Samples of the G0Cr13Co5Ni3Mo2V stainless bearing steel bars prepared in this embodiment were taken for performance testing. After performance heat treatment (quenching, deep cryogenic treatment, and two tempering treatments; quenching temperature controlled at 1020-1050℃, deep cryogenic treatment at (≤-73℃), and two tempering treatments, with tempering temperature controlled at 300-500℃), the room temperature Charpy V-notch impact value was ≥100J, as shown in Table 1. After surface carbon and nitrogen treatment of the matrix, it met the pH=3.5 acid test requirements. After surface strengthening treatment, the room temperature surface hardness was ≥60HRC, and the surface hardness at 400℃ was ≥58HRC, exhibiting good high-temperature performance. The steel grade of this embodiment with surface strengthening treatment had a 5GPa contact fatigue L10 ≥1×10⁻⁶. 8 .

[0054] Example 2 This embodiment prepares a G0Cr13Co5Ni3Mo2V stainless bearing steel bar, and the main steps are as follows: 1) Preparation of consumable ingots: First, a high-purity electrode blank is prepared; then, the high-purity electrode blank is subjected to vacuum consumable remelting to obtain consumable ingots. The chemical composition of the consumable ingots, by weight percentage, is as follows: C: 0.12wt%; Si: 0.5wt%; Mn: 0.8wt%; P: 0.006wt%; S≤0.0008wt%; Cr: 13.5wt%; Ni: 2.6wt%; Co: 6wt%; Mo: 2.5wt%; V: 0.5wt%; W: 0.2wt%; Nb: 0.03wt%; Al: 0.045wt%; balance Fe.

[0055] The specific steps are as follows: Preparation of high-purity electrode blanks: Electrode blanks are prepared by vacuum induction melting. First, high-quality iron-based raw materials (meeting the following requirements: TO=25ppm, S=0.0005wt%, P=0.004wt%, Ti=0.0006wt%), along with other alloys and carbon, are added to a vacuum induction furnace according to the lower limit of the target composition. After vacuuming, the metal is then electrically heated to melt it. The impurity elements in the added alloys must meet the technical requirements of S≤0.0008wt%, P≤0.0050wt%, and Ti≤0.0012wt% in the prepared high-purity electrode blank. After the molten metal melts, a low-temperature vacuum carbon deoxidation operation is performed at 1550℃ for 30 minutes, controlling the TO at 13ppm. Then, the composition of the alloy liquid is adjusted, followed by Al deoxidation for 30 minutes. Then, rare earth elements (0.025 wt% of the molten metal) are added to the molten metal for final deoxidation. The refining stirring time is controlled at 45 min, and the alternating stirring operation is performed 5 times. Finally, the molten steel (metal) is poured into an tundish using a slag-blocking weir to prepare an electrode billet. The Al content in the prepared electrode billet is controlled at 0.045 wt%.

[0056] Preparation of consumable ingots: The electrode blanks after vacuum induction melting are subjected to vacuum consumable remelting to prepare consumable ingots. Specifically, the electrode blanks are subjected to vacuum consumable remelting; during the vacuum consumable remelting process, the melting power is adjusted and forced cooling of the crystallizer is applied. Under water-cooled crystallizer conditions, gap air cooling is added to control the depth / width ratio of the molten pool ("depth" refers to the center depth of the molten pool; "width" refers to the diameter of the consumable ingot) to be 0.55. The consumable ingots meet the following requirements: TO≤6ppm, S≤0.002wt%, P≤0.006wt%, Ti≤0.0020wt%.

[0057] After the head and tail ends of the consumable ingot are removed, the carbon composition fluctuation of the consumable ingot cross section is controlled to ≤0.04%, and there is no point segregation in the low magnification of the consumable ingot cross section.

[0058] The consumable ingot is subjected to a second annealing treatment and a surface peeling treatment in sequence. The second annealing treatment includes: first holding the consumable ingot at a temperature of 830℃ for 1.5h / 25mm, then lowering the temperature to 750℃, and then holding the consumable ingot at this temperature for 2h / 25mm.

[0059] 2) High-temperature homogenization treatment: The consumable ingot is heated, first held at 600℃ for 5 hours, then held at 800℃ for 5 hours. Next, the temperature is raised to 1140±10℃ for pre-deformation, where the forging ratio is ≥2. Finally, a high-temperature homogenization diffusion treatment is performed at 1200℃ for 30 hours.

[0060] Among them, the steel ingot obtained after high-temperature homogenization treatment of the consumable ingot has the following characteristics: the δ ferrite content is ≤3% and the maximum size of carbides is ≤3μm, as observed by metallographic method.

[0061] 3) Hot Deformation Process: The steel ingot, after high-temperature homogenization, is forged and rolled (first forged into 120mm×120mm×L square bars, then further rolled into bars with a diameter of φ90mm or less) to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bars. To obtain bars with a diameter φ of 75mm, a high-speed forging mill is used for three upsetting and drawing operations during the forging process; the forging ratio for each operation is ≥4, and the total forging ratio is ≥16; and a symmetrical pressing method is used during each drawing to ensure that the center position of the steel ingot does not shift. During the deformation process, the forging temperature is not lower than 950℃.

[0062] 4) First annealing treatment: Hold at 690℃ for 2 hours / 25 minutes to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bars.

[0063] See Figure 2 In this embodiment, no δ-ferrite was observed in the G0Cr13Co5Ni3Mo2V stainless bearing steel bar. The maximum size of the carbides was ≤0.5μm, and they were uniformly distributed. The grain size of the bar was grade 6.5. Furthermore, the bar contained: TO=4ppm, inclusion size <6μm, and inclusion number density ≤2.5 inclusions / mm. 2 .

[0064] Samples of the G0Cr13Co5Ni3Mo2V stainless bearing steel bars prepared in this embodiment were taken for performance testing. After performance heat treatment (quenching, cryogenic treatment, and two tempering treatments; quenching temperature controlled at 1020-1050℃, cryogenic treatment at (≤-73℃), and two tempering treatments, with tempering temperature controlled at 300-500℃), the room temperature Charpy V-notch impact value of the bars was ≥135J, as shown in Table 1. After surface carbon and nitrogen treatment of the matrix, the pH=3.5 acid test was met, and the surface hardness after surface strengthening treatment was ≥60HRC at room temperature and ≥58HRC at 400℃. The steel grade of this embodiment with surface strengthening treatment had a 5GPa contact fatigue L10 ≥1.5×10 8 .

[0065] Example 3 This embodiment prepares a G0Cr13Co5Ni3Mo2V stainless bearing steel bar, and the main steps are as follows: 1) Preparation of consumable ingots: First, a high-purity electrode blank is prepared; the high-purity electrode blank is then subjected to vacuum consumable remelting to obtain consumable ingots. The chemical composition of the consumable ingots, by weight percentage, is as follows: C: 0.07wt%; Si: 0.35wt%; Mn: 0.8wt%; P≤0.006wt%; S≤0.002wt%; Cr: 16wt%; Ni: 3.0wt%; Co: 4.5wt%; Mo: 1.6wt%; V: 0.42wt%; W: 0.35wt%; Nb: 0.01wt%; Al: 0.05wt%, with the balance being Fe. Specific steps are as follows: Preparation of high-purity electrode blanks: Electrode blanks are prepared by vacuum induction melting. First, high-quality iron-based raw materials (meeting the following requirements: TO=18ppm, S=0.0006wt%, P=0.004wt%, Ti=0.0007wt%), along with other alloys and carbon, are added to a vacuum induction furnace according to the lower limit of the target composition. After evacuation, the metal is then electrically heated to melt it. The impurity elements in the added alloys must meet the technical requirements of S≤0.0009wt%, P≤0.0050wt%, and Ti≤0.0012wt% in the prepared high-purity electrode blank. After the molten metal melts, vacuum carbon deoxidation is performed. The operating temperature is controlled at 1520℃, the vacuum degree is controlled at less than or equal to 50Pa, and the operating time is 30min, with TO controlled at 7ppm. Then, the composition of the alloy liquid was adjusted, followed by Al refining and deoxidation. The optimal refining stirring time for Al deoxidation was controlled at 50 min, and the operating temperature was controlled at 1590℃. Next, rare earth elements were added to the molten metal for final rare earth deoxidation (the amount of rare earth added was 0.02 wt% of the molten metal). The stirring was repeated four times, with a total operating time of 35 min, and the operating temperature was 1600℃. Finally, the molten steel (metal liquid) was poured into an tundish using a slag-blocking weir to prepare electrode billets. The Al content in the prepared electrode billets was controlled at 0.05 wt%.

[0066] Preparation of consumable ingots: The electrode blanks after vacuum induction melting are subjected to vacuum consumable remelting to prepare consumable ingots. Specifically, the electrode blanks are subjected to vacuum consumable remelting; during the vacuum consumable remelting process, the melting power is adjusted and forced cooling of the crystallizer is applied. Under water-cooled crystallizer conditions, gap air cooling is added to control the depth / width ratio of the molten pool ("depth" refers to the center depth of the molten pool; "width" refers to the diameter of the consumable ingot) to be 0.57. The consumable ingots meet the following requirements: TO≤6ppm, S≤0.002wt%, P≤0.006wt%, Ti≤0.0020wt%.

[0067] After cutting off 160mm from the head end and then 50mm from the tail end of the consumable ingot, the carbon composition fluctuation of the consumable ingot cross section is controlled to ≤0.04%, and there is no point segregation in the low magnification cross section of the consumable ingot.

[0068] The consumable ingot is subjected to a second annealing treatment and a surface peeling treatment in sequence. The second annealing treatment includes: first holding the consumable ingot at a temperature of 830℃ for 2.5h / 25mm, then lowering the temperature to 730℃, and then holding the consumable ingot at this temperature for 1h / 25mm.

[0069] 2) High-temperature homogenization treatment: The consumable ingot is heated and first held at 600°C for 5 hours, then held at 800°C for 5 hours. Finally, a high-temperature homogenization diffusion treatment is performed at 1250°C for 25 hours.

[0070] Among them, the steel ingot obtained after high-temperature homogenization treatment of the consumable ingot has the following characteristics: the δ ferrite content is ≤2% and the maximum size of carbides is ≤3μm, as observed by metallographic method.

[0071] 3) Hot Deformation Process: The steel ingot, after high-temperature homogenization, is forged to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bars. To obtain bars with a diameter of φ100mm, a high-speed forging mill is used for three upsetting and drawing operations during the forging process; the forging ratio for each operation is ≥4, and the total forging ratio is ≥12; and a symmetrical pressing method is used during each drawing to ensure that the center position of the steel ingot does not shift. During the deformation process, the forging temperature is not lower than 950℃. The billet is transformed from φ406mm to φ100mm bars, and then the bars undergo a first annealing treatment.

[0072] 4) First annealing treatment: Hold at 720℃ for 2 hours / 25 minutes to obtain G0Cr13Co5Ni3Mo2V stainless bearing steel bars.

[0073] See Figure 3 In this embodiment, no δ-ferrite was observed in the G0Cr13Co5Ni3Mo2V stainless bearing steel bar, the maximum size of the carbides was ≤1μm, and the grain size of the bar was grade 6.0. Furthermore, the bar contained: TO=5ppm, inclusion size <5μm, and inclusion number density ≤2.5 inclusions / mm². 2 .

[0074] Samples of the G0Cr13Co5Ni3Mo2V stainless bearing steel bars prepared in this embodiment were taken for performance testing. After performance heat treatment (quenching, deep cryogenic treatment, and two tempering treatments; quenching temperature controlled at 1020-1050℃, deep cryogenic treatment at (≤-73℃), and two tempering treatments, with tempering temperature controlled at 300-500℃), the room temperature Charpy V-notch impact value of the bars was ≥130J, as shown in Table 1. After surface carbon and nitrogen treatment of the matrix, the pH=3.5 acid test was met, and the room temperature surface hardness after surface strengthening treatment was ≥60HRC, and the surface hardness at 400℃ was ≥58HRC. The steel grade of this embodiment with surface strengthening treatment had a 5GPa contact fatigue L... 10 ≥0.8×10 8 .

[0075] Table 1 compares the impact properties of G0Cr13Co5Ni3Mo2V stainless bearing steel bars.

[0076] It should be noted that: Example 2 satisfies the requirement that "the weight percentage of Cr element is 13-13.5 wt%", while Examples 1 and 3 do not satisfy the requirement that "the weight percentage of Cr element is 13-13.5 wt%". Obviously, Example 2 has better impact resistance and contact fatigue performance.

[0077] Comparative Example 1 Comparative Example 1 prepared a stainless bearing steel bar, which differed from Example 1 in that: The chemical composition of the stainless bearing steel bar in Comparative Example 1 is as follows: C: 0.07wt%; Si: 0.4wt%; Mn: 0.75wt%; P≤0.01wt%; S≤0.002wt%; Cr: 10wt%; Ni: 2.5wt%; Co: 5.5wt%; Mo: 2.0wt%; V: 0.6wt%; Al: 0.03wt%; balance Fe; The other steps and parameters are the same as in Example 1.

[0078] When the Cr content in Comparative Example 1 is below 12-16.5 wt%, and no trace elements W and Nb are added for grain refinement, the resulting bar after forging has a grain size of <5 grade and does not meet the requirements for acid corrosion test at pH=3.5.

[0079] Comparative Example 2 Comparative Example 2 prepared an M50NiL stainless bearing steel bar. The difference between Comparative Example 2 and Example 1 is that the stainless bearing steel in Comparative Example 2 is made of a different material than that in Example 1, but the other steps and parameters are the same.

[0080] Here, due to the significant differences in composition between M50NiL stainless bearing steel and G0Cr13Co5Ni3Mo2V stainless bearing steel, G0Cr13Co5Ni3Mo2V stainless bearing steel is significantly superior to M50NiL stainless bearing steel in terms of high-temperature hardness and corrosion resistance.

[0081] Comparative Example 3 Comparative Example 3 prepared a G0Cr13Co5Ni3Mo2V stainless bearing steel bar, which differed from Example 1 in that: In the process of preparing the electrode blank, only traditional Al deoxidation was used, without vacuum carbon deoxidation or rare earth final deoxidation. This resulted in the oxygen content in the consumable ingot prepared in the next step not being able to be stably reduced to below 6 ppm, and the inclusion size in the final prepared rod not being able to be stably <10 μm.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A G0 Cr13Co5Ni3Mo2V stainless bearing steel, characterized in that, The stainless bearing steel comprises the following chemical components in percentage by weight: C: 0.05-0.12wt%; Si: 0.1-0.6wt%; Mn: 0.5-1.0wt%; P≤0.01wt%; S≤0.002wt%; Cr: 12-16.5wt%; Ni: 2.0-3.0wt%; Co: 4.0-7.0wt%; Mo: 1.2-2.7wt%; V: 0.4-0.8wt%; W≤0.5wt%; Nb≤0.05wt%; Al: 0.02-0.05wt%; and the balance of Fe. Preferably, in the stainless bearing steel, the percentage by weight of the Cr element is 13-13.5wt%. Preferably, in the stainless bearing steel, the sum of the percentages by weight of the V element, the W element and the Nb element is ≤0.8wt%. The stainless bearing steel bar is prepared from the stainless bearing steel of claim 1.

2. A bar of G0Cr13Co5Ni3Mo2V stainless bearing steel, characterized in that, The grain size of the stainless bearing steel bar is ≥5 grade; preferably, the maximum size of the carbide in the stainless bearing steel bar is ≤0.5μm, preferably, the carbide is uniformly distributed; and / or 3. The G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to claim 2, characterized in that, In said stainless bearing steel bar: the delta ferrite content is ≤ 1 %, the maximum size of carbides is ≤ 2 μm, the T.O is ≤ 6 ppm, the size of inclusions is < 10 μm, the density of the number of inclusions is ≤ 4 per mm 2 ; and / or After quenching, deep cooling and multiple times of tempering treatment, the Charpy V-notch impact energy at room temperature of the stainless bearing steel bar is ≥100J; wherein, the quenching temperature is 1020-1050℃; the deep cooling temperature is ≤-73℃; the tempering temperature is 300-500℃; and preferably, the number of times of tempering treatment is ≥2.

4. The G0Cr13Co5Ni3Mo2V stainless bearing steel bar of claim 3, wherein, After surface carbonitriding treatment, the stainless bearing steel bar satisfies the PH=3.5 acid corrosion resistance experiment; and / or After surface strengthening treatment, the surface hardness of the stainless bearing steel bar at room temperature is ≥60HRC, and the surface hardness at 400℃ is ≥58HRC. It comprises the following steps:

5. The method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to any one of claims 2 to 4, characterized in that, Preparation of consumable ingot: the raw materials are subjected to vacuum induction melting treatment and refining treatment to obtain electrode blank; the electrode blank is subjected to vacuum consumable treatment to prepare consumable ingot meeting the set requirements; High-temperature homogenization treatment: the consumable ingot is subjected to high-temperature homogenization treatment to obtain steel ingot after high-temperature homogenization treatment; Hot deformation treatment: the steel ingot after high-temperature homogenization treatment is subjected to hot deformation treatment to obtain bar after hot deformation treatment; First annealing treatment: the bar after hot deformation treatment is subjected to first annealing treatment to obtain stainless bearing steel bar. In the step of preparing consumable ingot:

6. The method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to claim 5, characterized in that, ​ In the process of vacuum induction smelting and refining treatment, the raw materials are first smelted, and then deoxidized by low-temperature vacuum carbon after the raw materials are melted into liquid metal, wherein the time of vacuum carbon deoxidation is 30-50 min, the temperature is 1500-1550℃, and the vacuum degree is controlled to be ≤50 Pa, so that the T.O in the liquid metal is ≤20 ppm; then, the refining stage is entered, the alloy containing Si and Mn elements is added to adjust the composition of the liquid metal, and then Al element is added to the liquid metal for Al deoxidation, wherein the refining stirring time during Al deoxidation is controlled to be 30-50 min to reduce the dissolved oxygen in the liquid metal and make the inclusions fully float up; then, rare earth RE is added to the liquid metal for final deoxidation, wherein the refining stirring time during the final deoxidation is controlled to be 30-50 min, and the operating temperature is controlled to be below 1600℃; finally, pouring is carried out to obtain an electrode blank with T.O≤10 ppm; preferably, the addition amount of Al element is 0.02-0.05wt% of the mass of the liquid metal; the rare earth RE is a composite rare earth of Ce and La; preferably, the addition amount of rare earth RE is 0.01-0.03wt% of the mass of the liquid metal; and / or In the process of the vacuum consumable treatment, the ratio of the center depth of the molten pool to the diameter of the consumable ingot is controlled to be 0.55-0.65 to promote the floating of inclusions; and / or The consumable ingot meets the following requirements: T.O≤6 ppm, S≤0.002wt%, P≤0.006wt%, Ti≤0.0020wt%.

7. The method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to claim 5 or 6, characterized in that, Before the step of high-temperature homogenization treatment, it further includes: The consumable ingot is sequentially subjected to a second annealing treatment and a surface peeling treatment; Preferably, the second annealing treatment includes: first heat treating the consumable ingot at a temperature of 800-850℃ for 1.5-2.5h / 25mm, then reducing the temperature to 700-750℃, and heat treating the consumable ingot at the temperature for 1-2h / 25mm.

8. The method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to any one of claims 5 to 7, characterized in that, In the step of high-temperature homogenization treatment: The consumable ingot is heated to first heat treat the consumable ingot at a temperature of 500-600℃, then heat treat the consumable ingot at a temperature of 800-1000℃, and then heat to 1160-1250℃ for high-temperature homogenization diffusion treatment at the temperature; Preferably, the time of the high-temperature homogenization diffusion treatment is ≥20h; Preferably, the time of the first heat treatment is 2-6h; Preferably, the time of the second heat treatment is 2-6h; Preferably, after the second heat treatment and before the high-temperature homogenization diffusion treatment, the consumable ingot is further subjected to a pre-deformation treatment to promote δ ferrite transformation and carbide dissolution; preferably, the pre-deformation treatment includes: first heat treating the consumable ingot at 1130-1150℃, and then upsetting and elongating the consumable ingot; wherein the forging ratio is ≥2.

9. A method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to any one of claims 5 to 8, characterized in that, In the step of hot deformation treatment: The step of the thermal deformation treatment comprises: forging the high-temperature homogenized ingot to obtain a thermal deformation treated bar with a grain size≥5, a δ-ferrite content≤1% and a diameter of 90-130 mm; or forging the high-temperature homogenized ingot to obtain a square material; and then rolling the square material to obtain a thermal deformation treated bar with a grain size≥5, a δ-ferrite content≤1% and a diameter less than 90 mm; Preferably, the forging treatment comprises: at least twice upsetting and drawing; preferably, the ratio of each forging is≥2 and the total ratio of forging is≥8; preferably, the symmetric pressing method is used in each drawing to ensure that the center position of the ingot is not deviated; Preferably, the temperature of the forging treatment is not less than 950℃ during the deformation process; Preferably, the thermal deformation treated bar is cooled after the thermal deformation treatment, and preferably, the first annealing treatment is performed when the temperature of the bar is≤300℃.

10. The method of producing a G0 Cr13Co5Ni3Mo2V stainless bearing steel bar according to any one of claims 5 to 9, characterized in that, In the step of the first annealing treatment: After the first annealing treatment of the thermal deformation treated bar, the maximum size of the carbide in the stainless bearing steel bar is≤2μm; And / or The first annealing treatment comprises: first heat preservation of the thermal deformation treated bar at a temperature of 640-750℃, and the heat preservation time is 1.5-2.5h / 25mm.

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