CN-122013060-A - Component regulation and control technology for optimizing cold heading performance of 55Cr3 steel stabilizer bar

CN122013060ACN 122013060 ACN122013060 ACN 122013060ACN-122013060-A

Abstract

The invention relates to the technical field of ferrous metallurgy, and discloses a component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar, which comprises the steps of determining an S1 target component system, controlling the basis of smelting components of an S2 converter, accurately regulating and controlling refining components of an S3 LF furnace, controlling the contents of S4 vacuum treatment and gas, homogenizing and controlling components in an S5 continuous casting process, checking and adjusting components of a casting blank in a closed loop, wherein the process realizes accurate matching of plasticity and strength, and improves cold heading forming stability: the cold heading cracking rate is reduced to below 0.5 percent by optimizing the core element proportion (C0.50-0.61 percent, si 0.22-0.53 percent, mn 0.65-1.05 percent and Cr 0.68-1.03 percent) and considering the plasticity required by cold heading and the subsequent strengthening capability; the low-content alloying elements (Al, V and Mo) act synergistically to refine grains and improve structural stability, and the elongation after fracture is improved by 10% -15%, so that the complex cold heading forming requirement is completely met.

Inventors

YUAN LIN
LUO XIAO
YUAN YUAN
WANG XUJI
LIN DAN
HOU GUANGHAO
Pan Xiquan
WU MIN
DU JIANG
WANG JUN
XU RUIJUN

Assignees

湖南华菱湘潭钢铁有限公司

Dates

Publication Date: 20260512
Application Date: 20260226

Claims (10)

1. A component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar comprises determining an S1 target component system, controlling a smelting component foundation of an S2 converter, accurately regulating and controlling a refining component of an S3 LF furnace, controlling vacuum treatment and gas content of the S4, homogenizing and controlling components in a S5 continuous casting process, checking and adjusting components of an S6 casting blank in a closed loop, and is characterized in that the S1 target component system comprises an S101 core element, an S102 impurity element, an S103 alloy element and an S104 gas content; the basic control of smelting components of the S2 converter comprises the regulation and control of an S201 tapping end point, the operation of S202 slag-stopping tapping and the S203 pre-deoxidation control; the precise regulation and control of the refining components of the S3 LF furnace comprises S301 refining atmosphere control, S302 slagging, deoxidizing and desulfurizing, S303 component fine adjustment and S304 calcium treatment optimization; Wherein, the S4 vacuum treatment and gas content control comprises S401 vacuum process parameters, S402 soft argon blowing process and S403 gas detection and control; wherein, the component homogenization regulation and control in the S5 continuous casting process comprises S501 continuous casting process parameters, S502 electromagnetic stirring and soft reduction and S503 casting blank slow cooling; The S6 casting blank component inspection and closed loop adjustment comprises S601 sampling detection, S602 deviation adjustment and S603 batch tracing.
2. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S101 core elements comprise 0.50-0.61C, 0.22-0.53 Si, 0.65-1.05 Mn and 0.68-1.03 Cr, wherein the C element is precisely controlled in a medium carbon section, and plasticity and subsequent strengthening capability during cold heading are ensured; S102 impurity elements, namely P is less than or equal to 0.022, S is less than or equal to 0.018, cu is less than or equal to 0.28, ni is less than or equal to 0.23, harmful impurity content is strictly controlled, grain boundary segregation and brittle phase generation are reduced, and cold heading cracking risk is reduced; S103 alloy elements are Al 0.012-0.043, V less than or equal to 0.045 and Mo less than or equal to 0.07, al refines grains, V improves structural stability, mo assists in improving toughness, and the cold heading plasticity is prevented from being influenced in a low content range; S104 gas content is less than or equal to 18ppm of [ O ] and less than or equal to 1.8ppm of [ H ], and damage of gas inclusion to cold heading performance is reduced.
3. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S201 tapping terminal point regulation and control comprises the following steps of controlling 0.07% -0.11% of target C, less than or equal to 0.014% of P, and 1570-1595 ℃ of tapping temperature, so that molten steel peroxidation caused by over-blowing is avoided, and the subsequent component regulation and deoxidization effects are influenced; S202 slag-stopping tapping operation, namely adopting a double slag-stopping process, strictly forbidding slag discharging, adding deoxidizing agents (aluminum particles and silicon carbide), alloys (medium carbon ferrochrome and medium carbon ferromanganese) and low-titanium slag materials along the steel flow during tapping for 1/4, controlling the Al content of an entering station of an LF furnace to be more than or equal to 0.032%, and laying a foundation for accurate regulation and control of components; S203, pre-deoxidizing control, namely adding deoxidizing agent in stages in the tapping process, controlling the total amount to be 8-12kg/t of steel, primarily reducing the oxygen content of molten steel, and reducing oxide inclusion generation.
4. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1 is characterized in that S301 refining atmosphere is controlled, wherein total argon blowing time of molten steel is 48-62 min, micro-positive pressure reducing atmosphere in a furnace is maintained, residual oxygen content is less than or equal to 1.2%, and component fluctuation and inclusion increase caused by secondary oxidation are avoided.
5. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1 is characterized in that S302 is used for slagging, deoxidizing and desulfurizing, wherein white slag is produced rapidly, the alkalinity of the white slag is controlled to be 4.8-7.2, the slag amount is 12kg/t-16kg/t, the white slag holding time is 28min-36min, the consumption of a diffusion deoxidizer (aluminum particles, carbon powder and silicon carbide) is more than or equal to 78 kg/furnace, al is regulated in place once when white slag is refined, and later-stage aluminum supplementing wires are forbidden to ensure uniformity of components.
6. The component regulating and controlling process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the component S303 is finely regulated, namely, the component S is precisely regulated element by element according to target components, the C element is regulated by carbon wires, al components are prevented from being regulated in the later stage of refining, mn and Cr alloys are added in batches, the stable absorption rate is ensured, and the fluctuation of the final component is controlled within +/-5% of the target range.
7. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S304 calcium treatment is optimized by feeding 110m-130m of Ca wire into a casting furnace and 70m-90m of Ca wire into a continuous casting furnace, finely adjusting the wire feeding amount according to molten steel fluidity and inclusion morphology, and modifying Al 2 O 3 inclusion into low-melting-point spherical calcium aluminate so as to reduce stress concentration during cold heading.
8. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S401 vacuum process parameters comprise that the standing time of a VD furnace is more than or equal to 38min, the standing time of an RH furnace is more than or equal to 33min, the vacuum pumping is carried out until the pressure is less than or equal to 72Pa, the holding time is more than or equal to 13min, and H, O gas in molten steel is removed effectively; S402, soft argon blowing is carried out for 8-28 min after the air break, the argon flow is controlled at 0.3m 3 /h-0.6m 3 /h, the micro-bubble floating and the inclusion polymerization removal are promoted, and the white point defect formed by gas residues is avoided; S403, gas detection and control, namely, pumping and fixing hydrogen for each casting time to be more than or equal to 1 furnace, ensuring that [ H ] is less than or equal to 1.8ppm, and sampling and detecting [ O ] of a steel billet, and prolonging the vacuum treatment time or supplementing deoxidizer until the requirement is met.
9. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S501 continuous casting process parameters are that 280mm multiplied by 280mm square billets are adopted for continuous casting, the pulling speed is 0.78m/min-0.92m/min, the specific water quantity is 0.26L/kg-0.36L/kg, the superheat degree of ladle molten steel is controlled to be less than or equal to 37 ℃ when a casting furnace is started, and the continuous casting furnace is at 13 ℃ to 27 ℃, so that component segregation caused by the superheat degree is avoided; S502, electromagnetic stirring and light pressing, namely starting the electromagnetic stirring of a crystallizer (current 210A-290A, frequency 2.2Hz-3.2 Hz) and the electromagnetic stirring of the tail end (current 370A-430A, frequency 4.3Hz-5.7 Hz), and adopting a combined process of light pressing and heavy pressing to inhibit center segregation and loosening and ensure the uniformity of casting blank components; And S503, slow cooling the casting blank, namely closely arranging and stacking the casting blank or slowly cooling the casting blank in a pit for 22-32 h, slowly releasing casting stress, and avoiding the formation of hard and brittle tissues in a component segregation region and influencing cold heading plasticity.
10. The component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar according to claim 1, wherein the S601 sampling and detection comprises the steps of taking more than or equal to 1 casting blank sample per flow, performing chemical component full analysis (gas content) and low-power tissue inspection, and ensuring that components meet a target range, wherein the general porosity in the low-power tissue and the ingot segregation level are less than or equal to 1.8 level; S602, deviation adjustment, namely, if the components exceed the target range, discharging the alloy to a furnace for targeted adjustment of the alloy addition (C is lower, carbon lines are added, cr is insufficient, and the medium carbon ferrochrome consumption is increased), and if the gas content exceeds the standard, optimizing the vacuum treatment time and the soft argon blowing parameters; And S603, carrying out batch tracing, namely establishing a component database, recording component adjustment data of each smelting, refining and continuous casting process to form closed-loop control, ensuring the stability of the components of the subsequent production and ensuring the consistency of cold heading performance.

Description

Component regulation and control technology for optimizing cold heading performance of 55Cr3 steel stabilizer bar Technical Field The invention relates to the technical field of ferrous metallurgy, in particular to a component regulation and control process for optimizing cold heading performance of a 55Cr3 steel stabilizer bar. Background The cold heading process is a core process for preparing key parts such as an automobile stabilizer bar by using spring round steel, and the materials are required to have excellent plasticity and strength balance, so that the defects of cracking, uneven deformation and the like in the cold heading process are avoided. Along with the continuous promotion of the automobile industry to spare part lightweight, high accuracy, market has put forward more harsh standard to the cold heading performance of spring round steel, not only need the shaping stability when guaranteeing the cold heading, still need compromise the mechanical properties reliability after the follow-up heat treatment. The traditional component regulating and controlling process has the technical bottlenecks that firstly, the proportion of core elements is unbalanced, the control precision of C content is insufficient, excessive addition or improper proportion of alloy elements such as Si, mn, cr and the like is caused, so that the plasticity and strength of materials are difficult to be compatible, cracking is easily caused by stress concentration during cold heading, secondly, impurity elements (P, S and the like) and gas contents ([ O ], [ H ]) are not strictly controlled, P, S is easy to form a low-melting-point brittle phase, the defect of white spots is easily formed during gas inclusion, the cold heading plasticity is remarkably reduced, thirdly, deoxidization and desulfurization are not thorough in the refining process, nonmetallic inclusion (such as Al 2O3) is irregular in morphology, becomes a stress concentration source during cold heading, so that the cracking risk is aggravated, fourthly, component segregation is serious during continuous casting, the difference between the center and the surface component is large, the uniformity of the cold heading performance is poor, and a closed-loop regulating mechanism is lacked, so that the requirement of the consistency of cold heading performance is difficult to be met for large-scale production. These problems seriously affect the qualification rate of products, increase the production cost, restrict the application of the spring round steel in the field of high-end automobile parts, and need to be solved by an accurate and efficient component regulation and control process. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides a component regulation and control process for optimizing the cold heading performance of a 55Cr3 steel stabilizer bar, which has the advantages of accurate plastic and strength matching, improved cold heading forming stability and the like, and solves the problems that the plastic and strength of the material are difficult to be compatible, and the cracking is easy to be caused by stress concentration during cold heading. (II) technical scheme In order to achieve the aim of precisely matching the plasticity and the strength and improving the cold heading forming stability, the invention provides the following technical scheme that the component regulation and control process for optimizing the cold heading performance of a 55Cr3 steel stabilizer bar comprises the steps of determining an S1 target component system, controlling the smelting component basis of an S2 converter, precisely regulating and controlling the refining component of an S3 LF furnace, controlling the vacuum treatment and the gas content of the S4, homogenizing and controlling the component in the S5 continuous casting process, checking and adjusting the component of a casting blank in a closed loop, wherein the S1 target component system comprises an S101 core element, an S102 impurity element, an S103 alloy element and an S104 gas content; the basic control of smelting components of the S2 converter comprises the regulation and control of an S201 tapping end point, the operation of S202 slag-stopping tapping and the S203 pre-deoxidation control; the precise regulation and control of the refining components of the S3 LF furnace comprises S301 refining atmosphere control, S302 slagging, deoxidizing and desulfurizing, S303 component fine adjustment and S304 calcium treatment optimization; Wherein, the S4 vacuum treatment and gas content control comprises S401 vacuum process parameters, S402 soft argon blowing process and S403 gas detection and control; wherein, the component homogenization regulation and control in the S5 continuous casting process comprises S501 continuous casting process parameters, S502 electromagnetic stirring and soft reduction and S503 casting blank slow cooling; The S