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CN-122013071-A - High-strength anti-deformation light steel keel and preparation method thereof

CN122013071ACN 122013071 ACN122013071 ACN 122013071ACN-122013071-A

Abstract

The invention relates to the technical field of building structural materials, in particular to a high-strength anti-deformation light steel keel and a preparation method thereof, comprising the following steps of S1, proportioning according to preset raw material proportions, and smelting by adopting an electric furnace to obtain a plate blank; the method comprises the steps of S2, heating, heat preservation and multi-pass hot continuous rolling, then, on-line accelerated cooling to obtain hot rolled strip steel, S3, coiling the hot rolled strip steel cooled in the step S2, S4, pickling to remove oxidized iron scales, then, cold rolling to a target thickness to obtain a cold rolled strip steel, S5, continuously cold bending and forming to obtain a keel semi-finished product, S6, pre-straining the keel semi-finished product, then, carrying out low-temperature aging treatment, and S7, carrying out surface coating and plating treatment to obtain a high-strength anti-deformation light steel keel finished product. According to the invention, through the collaborative design of alloy component optimization, tissue strengthening control and surface coating, the comprehensive improvement of the light steel keel in the aspects of high strength, deformation resistance and corrosion resistance is realized.

Inventors

  • ZHANG MINGQUAN
  • NIU JUN
  • WU LONGLONG

Assignees

  • 泰山石膏(广东)有限公司

Dates

Publication Date
20260512
Application Date
20260210

Claims (10)

  1. 1. A high-strength deformation-resistant light steel keel is characterized by being prepared from the following raw materials, by weight, 0.05-0.15% of C, 0.10-0.35% of Si, 0.80-1.60% of Mn, 0.025% of P, 0.020% of S, 0.015-0.045% of Nb, 0.03-0.08% of V, 0.01-0.04% of Ti, 0.20-0.50% of Cu, 0.15-0.40% of Cr, 0.015-0.050% of Al, 0.007% of N, 0.05-0.20% of Mo, 0.10-0.30% of Ni and the balance of Fe.
  2. 2. The high-strength deformation-resistant light steel keel according to claim 1, wherein the cross section of the light steel keel is C-shaped, U-shaped or L-shaped, and the web or the flange of the light steel keel is provided with reinforcing ribs, concave-convex lines or lightening holes which are regularly distributed.
  3. 3. A method for preparing a high-strength anti-deformation light steel keel, which is used for preparing the high-strength anti-deformation light steel keel according to any one of claims 1-2, and is characterized by comprising the following steps: S1, proportioning according to the raw material ratio of claim 1, smelting by adopting an electric furnace, and continuously casting to obtain a slab; S2, heating, preserving heat and carrying out multi-pass hot continuous rolling on the slab, and then carrying out online accelerated cooling to obtain hot rolled strip steel; S3, coiling the hot rolled strip steel cooled in the step S2 to obtain a hot rolled coil; S4, pickling the hot rolled coil to remove oxidized iron scales, and then cold-rolling to a target thickness to obtain a cold-rolled steel strip; S5, continuously cold-bending the cold-rolled steel strip to form a keel semi-finished product with a preset cross-sectional shape; s6, pre-straining the keel semi-finished product, and then performing low-temperature aging treatment to promote microalloy elements and alloy elements in the raw materials to form a reinforced precipitated phase; And S7, carrying out surface coating treatment on the semi-finished keel product subjected to the aging treatment in S6, and finishing to obtain a high-strength anti-deformation light steel keel finished product.
  4. 4. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein the step S1 specifically comprises: s11, weighing the components according to the preset raw material proportion, and placing the components in an electric furnace; s12, smelting in an electric furnace, and controlling the tapping temperature to be 1620-1660 ℃; S13, transferring the molten steel into an LF refining furnace, and deoxidizing and desulfurizing under the protection of argon, wherein the refining time is 25-45 minutes; S14, transferring refined molten steel into an RH vacuum circulation degassing device, controlling the vacuum degree to be 50-100Pa, and treating for 15-25 minutes; S15, injecting the treated molten steel into a crystallizer for continuous casting, controlling the pulling speed to be 1.2-1.6m/min, and controlling the cooling water flow of the crystallizer to be 120-180m3/h to obtain a slab with the thickness of 150-220 mm.
  5. 5. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein said S2 specifically comprises: s21, conveying the plate blank into a heating furnace, heating to 1180-1250 ℃, and preserving heat for 1-3 hours; S22, rolling the heated and heat-preserved plate blank for 9-12 times, wherein the accumulated rolling reduction rate of the last three times is not lower than 40%, and the final rolling temperature is controlled to be 860-920 ℃; S23, immediately performing laminar cooling on the strip steel after finish rolling, and cooling the strip steel to 550-650 ℃ at a cooling rate of 15-40 ℃ per second to obtain the hot-rolled strip steel with a phase change structure.
  6. 6. The method for preparing a high-strength and deformation-resistant light steel keel according to claim 3, wherein the step S3 specifically comprises: s31, leading the head of the strip steel into a coiling machine, and coiling into coils under tension control to obtain hot-rolled coils; s32, placing the hot rolled coil in air and performing self-tempering treatment by using the waste heat of the hot rolled coil.
  7. 7. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein said S4 specifically comprises: s41, after uncoiling the hot rolled coil, leading the hot rolled coil to pass through a hydrochloric acid pickling tank, wherein the concentration of hydrochloric acid is 12-18wt%, the pickling temperature is 70-85 ℃, and the pickling time is 90-180 seconds, so as to remove iron scales on the surface of the hot rolled coil; S42, carrying out multi-pass cold rolling on the strip steel subjected to acid washing, cleaning and drying, wherein the total reduction rate is 50% -70%, and the cold-rolled strip steel with the thickness of 0.4-1.2mm is obtained.
  8. 8. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein said S5 specifically comprises: s51, uncoiling the cold-rolled steel strip, and straightening the cold-rolled steel strip through a straightener to eliminate poor plate shape; S52, continuously feeding the straightened steel strip into a cold bending forming unit consisting of 12-20 forming rollers, wherein the hole profile of each forming roller is changed in sequence, so that the steel strip is gradually bent at room temperature to form a continuous section with a preset cross-sectional shape; and S53, dynamically sizing and cutting off the continuous section bar according to a set length by using a flying saw or a hydraulic punching and shearing machine to obtain the keel semi-finished product.
  9. 9. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein said S6 specifically comprises: s61, placing the keel semi-finished product into a stretcher, and applying 0.8% -1.5% of tensile plastic strain along the longitudinal direction of the keel semi-finished product; S62, placing the pre-strained keel semi-finished product into a continuous ageing furnace, preserving heat for 45-90 minutes at the temperature of 300-380 ℃, and then air-cooling to room temperature.
  10. 10. The method for manufacturing a high-strength and deformation-resistant light steel keel according to claim 3, wherein said S7 specifically comprises: S71, degreasing, washing, acid washing activation and washing drying are sequentially carried out on the semi-finished keel product treated in the step S6, wherein the acid washing activation liquid is sulfuric acid solution with the concentration of 8-12wt% and the treatment time is 30-90 seconds; S72, immersing the pretreated keel semi-finished product into zinc-aluminum-magnesium alloy molten plating solution at 450-470 ℃ for 3-10 seconds, and controlling the thickness of the plating layer by an air knife and cooling to form a metal plating layer with the weight of 120-275g/m < 2 >; S73, coating a layer of chromium-free passivating agent or aqueous acrylic resin sealing agent with the thickness of 1-5 mu m on the keel with the metal coating; S74, cutting the coated keel to a fixed length, performing pressure straightening through a straightener to control straightness, checking and packaging to obtain the high-strength deformation-resistant light steel keel finished product.

Description

High-strength anti-deformation light steel keel and preparation method thereof Technical Field The invention relates to the technical field of building structural materials, in particular to a high-strength anti-deformation light steel keel and a preparation method thereof. Background Along with the continuous improvement of the requirements of the modern building industry on structure light weight, construction convenience and integral anti-seismic performance, the light steel joist has been widely applied to systems such as suspended ceilings, partition walls, roofs, light steel houses and the like due to the advantages of light weight, convenient installation, energy conservation, environmental protection and the like, and the light steel joist is required to have good forming performance and dimensional stability and also has high strength, corrosion resistance and deformation resistance in order to adapt to changeable use environments and long-term service conditions. However, the existing light steel keels mostly use common carbon steel or low alloy steel as a matrix material, and still face the problems of insufficient strength, poor long-dimension stability, easy deformation, low adhesion of a coating layer and the like in practical application, especially the hidden structural hazards of keel warpage, loosening of connecting points or corrosion resistance failure and the like are easy to occur in thin-specification, long-span or complex installation scenes, meanwhile, the current preparation process is mostly concentrated on conventional continuous rolling and simple cold roll forming, and lacks of systematic coupling of a microalloy precipitation strengthening mechanism, pre-strain aging treatment and interface collaborative coating technology, so that collaborative improvement of high strength and deformation resistance is difficult to realize. Therefore, there is a need for a high strength deformation-resistant light gauge steel and a method of making the same to address the above-mentioned problems. Disclosure of Invention Based on the above purpose, the invention provides a high-strength anti-deformation light steel keel and a preparation method thereof. A high-strength deformation-resistant light steel keel is prepared from the following raw materials, by weight, 0.05-0.15% of C, 0.10-0.35% of Si, 0.80-1.60% of Mn, 0.025% of P, 0.020% of S, 0.015-0.045% of Nb, 0.03-0.08% of V, 0.01-0.04% of Ti, 0.20-0.50% of Cu, 0.15-0.40% of Cr, 0.015-0.050% of Al, 0.007% of N, 0.05-0.20% of Mo, 0.10-0.30% of Ni and the balance of Fe. Optionally, the cross section of the light steel joist is C-shaped, U-shaped or L-shaped, and the web plate or the flange of the light steel joist is provided with regularly distributed reinforcing ribs, concave-convex lines or lightening holes. The preparation method of the high-strength anti-deformation light steel keel comprises the following steps of: S1, proportioning according to the raw material ratio of claim 1, smelting by adopting an electric furnace, and continuously casting after LF external refining and RH vacuum degassing treatment to obtain a slab; S2, heating, preserving heat and carrying out multi-pass hot continuous rolling on the slab, and then carrying out online accelerated cooling to obtain hot rolled strip steel; S3, coiling the hot rolled strip steel cooled in the step S2 to obtain a hot rolled coil; S4, pickling the hot rolled coil to remove oxidized iron scales, and then cold-rolling to a target thickness to obtain a cold-rolled steel strip; S5, continuously cold-bending the cold-rolled steel strip to form a keel semi-finished product with a preset cross-sectional shape; s6, pre-straining the keel semi-finished product, and then performing low-temperature aging treatment to promote microalloy elements and alloy elements in the raw materials to form a reinforced precipitated phase; And S7, carrying out surface coating treatment on the semi-finished keel product subjected to the aging treatment in S6, and finishing to obtain a high-strength anti-deformation light steel keel finished product. Optionally, the S1 specifically includes: s11, weighing the components according to the preset raw material proportion, and placing the components in an electric furnace; s12, smelting in an electric furnace, and controlling the tapping temperature to be 1620-1660 ℃; S13, transferring the molten steel into an LF refining furnace, and deoxidizing and desulfurizing under the protection of argon, wherein the refining time is 25-45 minutes; S14, transferring refined molten steel into an RH vacuum circulation degassing device, controlling the vacuum degree to be 50-100Pa, and treating for 15-25 minutes; S15, injecting the treated molten steel into a crystallizer for continuous casting, controlling the pulling speed to be 1.2-1.6m/min, and controlling the cooling water flow of the crystallizer to be 120-180m3/h to obtain a slab with the thickness of 150-220 mm. Optionally,