CN117844280A - High-temperature antioxidant coating for steel billets and coating method thereof - Google Patents
High-temperature antioxidant coating for steel billets and coating method thereof Download PDFInfo
- Publication number
- CN117844280A CN117844280A CN202410263404.3A CN202410263404A CN117844280A CN 117844280 A CN117844280 A CN 117844280A CN 202410263404 A CN202410263404 A CN 202410263404A CN 117844280 A CN117844280 A CN 117844280A
- Authority
- CN
- China
- Prior art keywords
- coating
- billet
- steel billet
- weight
- steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 161
- 239000010959 steel Substances 0.000 title claims abstract description 161
- 238000000576 coating method Methods 0.000 title claims abstract description 135
- 239000011248 coating agent Substances 0.000 title claims abstract description 111
- 239000003963 antioxidant agent Substances 0.000 title description 4
- 230000003078 antioxidant effect Effects 0.000 title description 4
- 239000007921 spray Substances 0.000 claims abstract description 52
- 238000010438 heat treatment Methods 0.000 claims abstract description 45
- 238000005507 spraying Methods 0.000 claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 29
- 239000002904 solvent Substances 0.000 claims abstract description 22
- 239000011230 binding agent Substances 0.000 claims abstract description 11
- 229910004298 SiO 2 Inorganic materials 0.000 claims abstract description 10
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims abstract description 6
- 230000003064 anti-oxidating effect Effects 0.000 claims abstract description 5
- 230000003647 oxidation Effects 0.000 claims description 22
- 238000007254 oxidation reaction Methods 0.000 claims description 22
- 239000003973 paint Substances 0.000 claims description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 8
- 238000007605 air drying Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 14
- 238000005096 rolling process Methods 0.000 description 27
- 238000001816 cooling Methods 0.000 description 18
- 238000004519 manufacturing process Methods 0.000 description 17
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 16
- 238000000227 grinding Methods 0.000 description 15
- 238000005496 tempering Methods 0.000 description 12
- 238000002360 preparation method Methods 0.000 description 11
- 230000000694 effects Effects 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 230000007547 defect Effects 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 230000008901 benefit Effects 0.000 description 7
- 238000005098 hot rolling Methods 0.000 description 7
- 239000000843 powder Substances 0.000 description 7
- 238000000498 ball milling Methods 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 238000001514 detection method Methods 0.000 description 6
- 238000010791 quenching Methods 0.000 description 6
- 230000000171 quenching effect Effects 0.000 description 6
- 239000007769 metal material Substances 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 238000002791 soaking Methods 0.000 description 5
- 239000011651 chromium Substances 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000004321 preservation Methods 0.000 description 4
- 238000004381 surface treatment Methods 0.000 description 4
- 238000010301 surface-oxidation reaction Methods 0.000 description 4
- 238000010998 test method Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000005422 blasting Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000011253 protective coating Substances 0.000 description 3
- 238000005728 strengthening Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 229940090961 chromium dioxide Drugs 0.000 description 1
- IAQWMWUKBQPOIY-UHFFFAOYSA-N chromium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Cr+4] IAQWMWUKBQPOIY-UHFFFAOYSA-N 0.000 description 1
- AYTAKQFHWFYBMA-UHFFFAOYSA-N chromium(IV) oxide Inorganic materials O=[Cr]=O AYTAKQFHWFYBMA-UHFFFAOYSA-N 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 150000004677 hydrates Chemical class 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000006060 molten glass Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000004482 other powder Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 238000011895 specific detection Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
- B05D7/14—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials to metal, e.g. car bodies
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
- B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
- C09D1/02—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances alkali metal silicates
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
- C09D7/40—Additives
- C09D7/60—Additives non-macromolecular
- C09D7/61—Additives non-macromolecular inorganic
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
- C21D1/72—Temporary coatings or embedding materials applied before or during heat treatment during chemical change of surfaces
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D2202/00—Metallic substrate
- B05D2202/10—Metallic substrate based on Fe
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Inorganic Chemistry (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a high-temperature antioxidation coating for a steel billet and a coating method thereof. The coating consists of 30-60 parts by weight of SiO 2 3-20 parts by weight of Al 2 O 3 5-18 parts by weight of ZrO 2 1 to 12 parts by weight of SiC,1 to 8 parts by weight of C and 1 to 3 parts by weight of B 4 And C, 2-16 parts by weight of binder and solvent. The coating method comprises the steps of adopting a spray gun with the caliber of 0.3-1.5 mm to spray the coating on the surface of a steel billet, wherein the air pressure of the spray gun is 0.5-0.8 MPa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between a nozzle and the surface of the steel billet is 20-35 cm, and the spray width is 20-45 cm; the superposition rate of two adjacent spraying widths is 30-40%. The coating disclosed by the invention can reduce the viscosity of the oxide skin generated by high-temperature heating, so that the oxide skin is easy to remove in the subsequent descaling process, and the component is safe and has no secondary pollution risk.
Description
Technical Field
The invention belongs to the technical field of coatings, and relates to a high-temperature antioxidant coating for a steel billet and a coating method thereof.
Background
In the process of preparing steel billets into steel products such as plates, bars, wires and the like, heating the billets is an essential important ring, for example, the billets to be rolled are usually required to be heated at 750-1200 ℃ in a heating furnace. In the heating process, the surface layer of the steel billet is contacted with oxygen in the environment to form oxide scales, and the oxide scales are pressed deep into the steel once entering the subsequent rolling process, so that the surface defects of the final steel product are caused. On the other hand, the generation of oxide skin can also cause the increase of the tissue loss of steel, and the treatment procedure of removing the oxide skin is added, so that the economic benefit of the production of steel materials is seriously affected.
In order to overcome the technical problems, one existing method is to coat protective coating on the surface of the steel billet before heating, so that the high-temperature oxidation-resistant protection of the surface of the steel billet is expected to be realized by utilizing the protective coating, and further, the surface defects of the steel product caused by oxide scale are reduced. In this application, these protective coatings are referred to as high temperature oxidation resistant coatings.
For example, chinese patent application publication No. CN111440990a mentions "spray" technique to prevent high temperature oxidation of billets, but specific coating compositions and effects of use are not disclosed therein; for another example, chinese patent application publication No. CN101857452A, CN104498683a discloses specific components of the coating, but the coating has the defects of high risk of secondary pollution (such as vanadium extraction tailings and chromium dioxide), complex and difficult control of components, high preparation difficulty and the like, and the high-temperature antioxidation effect is also general.
Disclosure of Invention
In order to solve the problem of surface oxidation in the heating process of a steel billet, the invention aims to provide a high-temperature antioxidation coating for the steel billet and a coating method thereof.
In order to achieve the above object, an embodiment of the present invention provides a high-temperature oxidation-resistant coating for a steel billet. The coating consists of a component A and a solvent;
the component A comprises: 30-60 parts by weight of SiO 2 3-20 parts by weight of Al 2 O 3 5-18 parts by weight of ZrO 2 1 to 12 parts by weight of SiC,1 to 8 parts by weight of C and 1 to 3 parts by weight of B 4 C, 2-16 parts by weight of a binder;
the weight of the solvent is 0.25-0.4 times of the weight of the component A.
Preferably, the component a also satisfies, in parts by weight: al (Al) 2 O 3 =(0.1~0.4)SiO 2 ，ZrO 2 = (1 to 1.5) SiC and sic+c+b 4 C=3~23。
Preferably, the binder has a composition K 2 SiO 3 Or Na (or) 5 P 3 O 10 。
Preferably, the solvent is water.
In order to achieve the above object, an embodiment of the present invention provides a method for applying the paint. The coating method adopts a spray gun with the caliber of 0.3-1.5 mm to spray the coating on the surface of the billet;
wherein, one-time comprehensive spraying is finished through multiple passes;
in each spray coating pass, the air pressure of the spray gun is 0.5-0.8 MPa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between the nozzle and the surface of the steel billet is 20-35 cm, and the spray width is 20-45 cm;
and starting from the 2 nd pass, the spray width sprayed in each pass is overlapped with 30-40% of the spray width sprayed in the previous pass.
Preferably, the thickness of the paint sprayed comprehensively each time is 0.2-0.3 mm.
Preferably, the coating method further comprises:
obtaining the heating time t of the steel billet in the furnace, and finishing spraying after finishing one-time comprehensive spraying on the surface of the steel billet when t is less than or equal to 400 min; when t is more than 400min, finishing the spraying after finishing n=ceil ((t-400 min)/30 min) times of full spraying on the surface of the steel billet.
Preferably, when t is more than 400min, the time interval between any two full spraying is not less than 15min.
Preferably, the steel billet after finishing the spraying is air-dried in an environment of a temperature T ℃ and a relative humidity P%, and the air-drying period is not less than (0.075 P×T) 0.5 +10~15)min。
In order to achieve the above object, an embodiment of the present invention provides a method for applying the paint. The coating method comprises the steps of adopting a spray gun with caliber of 0.3-1.5 mm to spray the coating on the surface of a steel billet, wherein the air pressure of the spray gun is 0.5-0.8 MPa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between a nozzle and the surface of the steel billet is 20-35 cm, the spray width is 20-45 cm, and the superposition rate of two adjacent spray widths is 30-40%;
when the heating time t of the steel billet is less than or equal to 400min, the thickness H of the paint sprayed on the surface of the steel billet is 0.2-0.3 mm;
when the heating time t of the steel billet is more than 400min, the thickness H of the paint sprayed on the surface of the steel billet is (0.2-0.3 mm) x ceil ((t-400 min)/30 min).
Compared with the prior art, the beneficial effects of an embodiment of the invention are as follows: the coating can be coated on the surface of a steel billet for high-temperature antioxidation protection on the surface of the steel billet, on one hand, compared with the existing known coating, the coating can greatly reduce the generation probability of oxide skin of the steel billet in the heating process, on the other hand, the coating can reduce the viscosity of the oxide skin of the steel billet generated by high-temperature heating, so that the oxide skin is easy to remove in the subsequent descaling process, namely, the removal rate is high, on the other hand, the coating has the advantages of safe components, no secondary pollution risk, low cost, small preparation difficulty, low cost, low preparation difficulty and high safety, improves the surface quality of a steel product, reduces the production cost and the production difficulty of the steel product, and has great comprehensive economic benefit and environmental protection benefit.
Drawings
FIG. 1 is a diagram showing the positional relationship between a billet and a spray gun in a method of applying a high temperature oxidation resistant coating according to an embodiment of the present invention;
fig. 2 is a schematic view of the surface of a steel billet sprayed in a certain pass in the method for applying the high-temperature oxidation-resistant coating according to an embodiment of the present invention.
Detailed Description
The technical scheme of the invention is further described below with reference to the accompanying drawings and specific embodiments.
An embodiment of the invention provides a high-temperature antioxidant coating, which consists of a component A and a solvent.
The component A comprises: 30-60 parts by weight of SiO 2 3-20 parts by weight of Al 2 O 3 5-18 parts by weight of ZrO 2 1 to 12 parts by weight of SiC,1 to 8 parts by weight of C and 1 to 3 parts by weight of B 4 C, 2-16 parts by weight of a binder; the weight of the solvent is 0.25-0.4 times of the weight of the component A.
As described above, the coating material according to the present embodiment, which is in a suspension state based on the components of the solvent, can be applied to the surface of a billet for high-temperature oxidation-resistant protection of the surface of the billet, for example: in the process of preparing steel products such as plates, bars and wires from billets, before the billets enter a heating furnace for heating, the coating is coated on the surfaces of the billets, so that the surfaces of the billets can be protected, on one hand, compared with the existing known coating, the coating can greatly reduce the generation probability of oxide skin of the billets in the heating process, on the other hand, the coating can reduce the viscosity of the oxide skin generated by high-temperature heating of the billets, so that the oxide skin is easy to remove in the subsequent descaling process, namely, the removal rate is high, on the other hand, the components of the coating are safe, have no secondary pollution risk, low cost and small preparation difficulty, and the coating with low cost, low preparation difficulty and high safety is used for improving the surface quality of the steel products, reducing the production cost and the production difficulty of the steel products, and has great comprehensive economic benefit and environmental benefit.
In a more preferred embodiment, the component A also satisfies the following in parts by weight: al (Al) 2 O 3 =(0.1~0.4)SiO 2 ，ZrO 2 = (1 to 1.5) SiC and sic+c+b 4 C=3~23。
The action and content of each component of the paint are described below:
SiO 2 : the coating formed by the paint provides a main substance with melt film shielding property; the coating is hard, and the strength of the coating at normal temperature when the surface of the steel billet is coated can be improved; the melting point is high, which is the key of high temperature resistance of the coating; the viscosity is moderate, and the adhesive compact membrane layer is a main component part at high temperature; the linear expansion coefficient is low, and the self-shedding property is provided for the coating; in the present embodiment, siO is contained in the whole of the remaining components excluding the solvent 2 30-60 parts by weight of a base;
Al 2 O 3 : the chemical stability is good, the melting point is high, and the high-temperature softening temperature of the coating can be improved; can be combined with SiO at high temperature 2 Combining the ceramic mullite to fill cracks and gaps of the coating in the film forming process, so that a coating formed by the coating is more compact; in the present embodiment, al is contained in the whole of the remaining components except the solvent 2 O 3 3-20 parts by weight of the composition;
ZrO 2 : the melting point is higher, and the monoclinic system is converted into tetragonal system at high temperature, so that the volume of a coating formed by the coating is expanded; the heat conductivity is poor, after the billet is discharged from the heating furnace, huge stress is generated between a coating formed by the coating and a substrate of the billet, and the coating is easy to fall off in the process of descaling by high-pressure water; in the present embodiment, zrO in the whole of the remaining components except the solvent 2 5-18 parts by weight of the composition;
SiC: the coating formed by the paint provides a redox primary substance; in the heating process, fe reacts with oxygen to generate SiO 2 And C, the surface oxidation of the steel billet can be effectively prevented; product SiO 2 An active ingredient for providing shielding properties to the melt film; the product C is taken as a reducing substance, and can also prevent the oxidation of the billet; in the embodiment, siC accounts for 1-12 parts by weight of the whole components except the solvent;
c: providing redox to the coating and relieving decarburization of the surface of the billet; in the embodiment, C accounts for 1-8 parts by weight of the whole components except the solvent;
B 4 c: the coating formed by the coating provides redox and inter-fusion reactive species; at a temperature of above 600 ℃, reacts with oxygen to generate B 2 O 3 Can effectively dissolve iron scales generated on the surface of the slab; in the present embodiment, B in the whole of the remaining components except the solvent 4 C accounts for 1-3 parts by weight;
and (2) a binder: is easily dissolved in a solvent, and can be used as a dispersing agent to be combined with a metal matrix at normal temperature when a coating in a suspension state is prepared by using the solvent; in the heating process of the steel billet, film forming can be assisted; in this embodiment, the binder accounts for 2 to 16 parts by weight of the entire components except the solvent.
The binder may be K 2 SiO 3 Or Na (or) 5 P 3 O 10 Preferably Na 5 P 3 O 10 Which is capable of forming stable hydrates; and the melting point is low, the fluidity is good, and the porous structure formed in the film forming process of the coating can be rapidly filled as a low-melting-point component in the heating process of the steel billet, and the porous structure is wrappedWrapping the surrounding powder to form a molten glass film.
In this embodiment, the weight of the flux is the remainder of the coating (i.e., siO 2 、Al 2 O 3 、ZrO 2 、SiC、C、B 4 The sum of C and the binder) by 0.25 to 0.4 times by weight.
Preferably, the solvent is water, so that the resource is rich, the cost is low, the acquisition is simple, and the safety and the harmlessness are realized.
Further, in one embodiment, the preparation process of the coating comprises the following steps: weighing each component according to the target weight portion, and adding SiC and B 4 Mixing other powder materials except the C, and then putting the mixture into a ball milling container made of SiC material for ball milling; after ball milling is completed, siC and B are mixed 4 C, mixing the powder obtained by ball milling, and then adding a solvent; stirring for 30-60 min at a rotating speed of 200-500 r/min to obtain a mixture with a viscosity of 3-15 mPa.s, and standing for 30min to obtain the coating.
Preferably, the granularity of the powder obtained by ball milling is 200-400 meshes.
In the ball milling process, a SiC grinding ball is adopted, the ball-material ratio (i.e. the mass ratio of the grinding ball to the powder) is 3.5:1-5:1, the rotating speed of the ball mill is (0.2-1.3) R r/s/mm, and the operation time is 2-4 hours. When the maximum particle diameter R of the original powder is larger than 15mm, a large grinding ball with the specification of 20mm and a middle grinding ball with the specification of 5mm are adopted, and the mass ratio of the large grinding ball to the middle grinding ball is 4.5:1-6:1; when the maximum particle diameter R of the original powder is 5-15 mm, a middle grinding ball with the specification of 5mm and a small grinding ball with the specification of 3mm are adopted, and the mass ratio of the middle grinding ball to the small grinding ball is 2:1-4:1; when the maximum particle diameter R of the original powder is smaller than 5mm, small grinding balls with the specification of 3mm are adopted, and the mass ratio of the large grinding balls to the medium grinding balls is 4.5:1-6:1.
Further, an embodiment of the present invention also provides a preferable application of the coating material, for example, a method for coating the coating material on a steel billet, and the coating method can be used to spray the surface of the steel billet, so as to maximally improve the surface protection effect of the coating material on the steel billet, avoid causing other defects, and simultaneously ensure the production efficiency of the steel product.
Referring to fig. 1 and 2, the coating method specifically includes: and spraying the coating on the surface of the steel billet by adopting a spray gun with the caliber of 0.3-1.5 mm.
Wherein, one-time comprehensive spraying is finished through multiple passes; in each spray coating pass, the air pressure of the spray gun is 0.5-0.8 MPa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between the nozzle and the surface of the steel billet is 20-35 cm, and the spray width is 20-45 cm; and starting from the 2 nd pass, the spray width sprayed in each pass is overlapped with 30-40% of the spray width sprayed in the previous pass.
Therefore, compared with the prior art, the coating method of the embodiment can enhance the surface protection effect of the coating on the steel billet, reduce the surface oxidation of the steel billet during heating more, further reduce the surface defect of the steel product caused by the oxide skin of the steel billet, reduce the production difficulty and the production cost caused by the oxide skin removal, and ensure that the coating thickness on each part of the surface of the steel billet is uniform due to the simple operation of the coating mode, so that the high-temperature oxidation resistance protection effect on each part of the surface of the steel billet is consistent.
Referring to fig. 1, during each pass of spraying, the spray gun 20 and the surface 101 of the steel billet 10 have a spraying angle α, and the spraying angle α is 25-40 ℃; typically, the billet 10 is placed horizontally and the surface 101 is horizontal, and the spray gun 20 sprays paint at an angle of 25 to 40 ℃ with respect to the horizontal.
Further, referring to fig. 1, the distance h between the spray gun 20 and the surface 101 of the billet 10 is 20 to 35cm during each spray.
In addition, referring to fig. 2, for the same surface 101 of the billet 10, multiple passes of spraying are required to complete one full spray, i.e., the entire surface 101 is sprayed with the coating. The spray width L of each pass is 20-45 cm; and, from the 2 nd pass, the spray width of each pass is overlapped with 30-40% of the spray width of the previous pass, for example, the spray width D2 of the 2 nd pass is overlapped with the spray width D1 of the 1 st pass by 30-40%, and the overlapped spray width is shown as the oblique line marked area in fig. 2. In terms of the change, namely, the superposition ratio of two adjacent spraying widths is 30-40%.
Preferably, the thickness of the paint sprayed comprehensively each time is 0.2-0.3 mm.
And, in a further preferred embodiment, the coating method further comprises:
obtaining the heating time t of the steel billet, namely, when the steel billet is used for producing a steel finished product, the steel billet needs to be heated after coating and before rolling;
when t is less than or equal to 400min, finishing spraying after finishing one-time comprehensive spraying on the surface of the steel billet, so that the thickness H of the coating on the surface of the obtained steel billet is 0.2-0.3 mm; when t is more than 400min, after n=ceil ((t-400 min)/30 min) times of full-surface spraying are finished on the surface of the steel billet, the spraying is finished, and the coating thickness H of the surface of the obtained steel billet is (0.2-0.3 mm) ×ceil ((t-400 min)/30 min).
Where ceil (x) represents an upward rounding function for x, that is, a minimum integer not smaller than x, for example, when x takes a value of 1.2, then ceil (x) takes a value of 2, more specifically, when t=440 min, (t-400 min)/30 min=1.33, then n=ceil (1.33) =2, and correspondingly, after performing 2 times of full spraying on the surface of the steel billet, spraying is finished.
Thus, in the preferred embodiment, the number of times of overall spraying is adjusted according to the heating time t of the steel billet in the furnace, so that the thickness H of the sprayed coating is adjusted, the quality of the coating formed by the coating on the surface of the steel billet is ensured, and the surface protection effect of the steel billet can be further greatly improved.
Further, when t is more than 400min, the time interval between any two full spraying is not less than 15min. Therefore, good compactness of a coating formed by the paint sprayed comprehensively each time can be ensured, and further, compactness of a complete coating formed finally is improved.
It will be appreciated that in the coating method, the surface of the steel billet is polished, for example by a polishing amount of 3mm, in advance before the coating is sprayed onto the surface of the steel billet, so as to ensure that the subsequently sprayed coating can be well fixed with the substrate of the steel billet.
In addition, the coating method further includes: the steel billet after finishing spraying is air-dried in an environment with the temperature T ℃ and the relative humidity P percent for a period of time not less than (0.075P multiplied by T) 0.5 +10-15) min, and then the billet can be heated in a heating furnace. Wherein the temperature T is preferably 15-30 ℃, and the relative humidity P% is preferably 40-70%.
In summary, compared with the prior art, the coating method of the embodiment can enhance the surface protection effect of the coating on the steel billet, reduce the surface oxidation of the steel billet during heating more, further reduce the surface defect of the steel product caused by the oxide skin of the steel billet, reduce the production difficulty and the production cost caused by the oxide skin removal, and ensure that the coating thickness on each part of the surface of the steel billet is uniform due to simple operation of the coating mode, so that the high-temperature oxidation resistance protection effect on each part of the surface of the steel billet is consistent.
The paint and the coating method thereof according to an embodiment of the present invention are described above, and a series of examples and comparative examples are provided below in order to more intuitively demonstrate the advantageous effects of the present invention.
< preparation of coating >
By Na 5 P 3 O 10 The coatings of the two examples in table 1 were formulated using the preparation method described in the present invention with binder and water as solvents.
TABLE 1
< preparation of billet >
The billet 1 is prepared by the prior known steelmaking technology.
Wherein, the billet 1 is low Wen Gangchong, and the chemical components of the billet are as follows by mass percent: 0.05-0.07% of C, 0.15-0.25% of Si, 0.5-0.7% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, less than or equal to 0.05% of Cr, 4.85-5.3% of Ni, less than or equal to 0.015% of Cu, less than or equal to 0.002% of Nb, less than or equal to 0.002% of Ti, 0.02-0.05% of Alt, less than or equal to 0.004% of N, mn=2Si+0.05-0.22% of Mn+Si: 0.65-0.95%, and the balance of iron and unavoidable impurities.
Specifically, specific chemical compositions of the steel slab 1 are shown in table 2.
TABLE 2
< coating application >
5 examples and 1 comparative example are provided, each of which surface-grinds the billet 1.
Then, as shown in table 3: examples 1 to 3 each applied a coating on the polished surface by a conventional coating method, in which the coating was applied to the surface of the billet 1 to a thickness of 0.4mm; while examples 4 and 5 each use the coating method provided by the invention to spray paint on the polished surface; the surface of the steel slab 1 of comparative example 1 was not coated with the paint.
Thereafter, the billets of each of the examples and comparative examples were transported to a heating furnace for heating at a soaking temperature of 1200 c for the furnace duration shown in table 3.
After the billets of each example and comparative example are discharged from the heating furnace, the surface quality is respectively subjected to metallographic structure detection, for example, the metallographic structure detection is carried out by using GB/T15125-2009 standards of samples and test methods for metallographic examination of metal materials, and specific detection results are shown in Table 3; the same descaling water pressure (specifically 18 MPa) is adopted to perform high-pressure water descaling, and then the surface quality of the descaled billet is subjected to metallographic structure detection, for example, the GB/T15125-2009 standard of a sample and a test method for metallographic examination of a metal material is adopted to perform structure detection, so that the removal rate of oxide skin is shown in a table 3.
TABLE 3
As can be seen from the above examples and comparative examples, the coating provided by the embodiment of the invention has a high-efficiency oxidation-resistant protective effect on billets, can greatly reduce the generation of oxide scale at high temperature, has poor viscosity of the oxide scale, is easy to remove scales, and can greatly solve the problem of surface defects caused by difficult removal of the oxide scale for low-temperature steel grade nickel-based steel. In addition, compared with the conventional brushing method, the coating mode of the embodiment can improve and ensure the uniformity of the coating, thereby influencing the generation, depth and removal rate of the oxide scale.
In the present application, "surface scale coverage" refers to the area ratio of the scale covered on the surface of the steel, and is characterized by the ratio of the scale area of the taken sample to the total area of the sample; "surface scale average depth" is characterized by the average of the scale depths of n samples taken; "scale removal rate" refers to the ratio of the scale area removed after descaling to the scale area before descaling, characterized by the formula (100% -S1/(surface scale coverage×s)) based on the scale area S1 of the sample (after descaling) and the total area S of the sample (after descaling).
Further, an embodiment of the invention also provides a production method of the low-temperature steel plate adopting the coating.
In view of the requirements of low-temperature steel on excellent mechanical properties and low-temperature toughness, P, S, N and other impurity elements are required to be controlled at a low level, and the nickel content of the low-temperature steel is high, so that the iron scale generated by the low-temperature steel in the heating process is high in viscosity and difficult to remove, and finally the surface quality and the low-temperature toughness are difficult to ensure simultaneously. The production method provided by the embodiment of the invention combines the control of heating, hot rolling and heat treatment while adopting the coating, thereby realizing the combination of the surface quality and the low-temperature toughness.
Specifically, the chemical components of the low-temperature steel billet comprise the following components in percentage by mass: 0.05-0.07% of C, 0.15-0.25% of Si, 0.5-0.7% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, less than or equal to 0.05% of Cr, 4.85-5.3% of Ni, less than or equal to 0.015% of Cu, less than or equal to 0.002% of Nb, less than or equal to 0.002% of Ti, 0.02-0.05% of Alt, less than or equal to 0.004% of N, and the balance of iron and unavoidable impurities.
The actions and amounts of the chemical components in the low-temperature billet according to the present embodiment will be described below.
C: is a strengthening element and also an austenite stabilizing element; if the C content is low, the strength of the steel plate is difficult to ensure; the C content is higher, so that the ductile-brittle transition temperature can be improved, and the low-temperature toughness of the steel plate is affected. Therefore, the lower the C content is, the better the strength is ensured. In the invention, the content of C is controlled to be 0.05-0.07%.
Si: is deoxidizing element and can inhibit the grain boundary segregation behavior of P. However, when the Si content is high, the low-temperature toughness of the steel sheet is affected. In the invention, the Si content is controlled to be 0.15-0.25%, so that the deoxidization effect is ensured and oxide inclusions in steel are reduced on the premise of not influencing the low-temperature toughness.
Mn: the Mn is added as a solid solution strengthening and fine crystal strengthening element and also an austenite stabilizing element, so that the hardenability of the material can be obviously improved; meanwhile, the steel plate is easy to segregate and form inclusion elements, and the fracture toughness and the low-temperature impact toughness of the steel plate are affected by excessive addition. In the invention, the Mn content is controlled to be 0.5-0.7%.
Ni: the hardenability of the steel plate can be improved, and the alloy is an effective element for improving fracture toughness and low-temperature toughness, but the alloy cost is higher, viscous iron scales are easy to generate on the surface at high temperature, and the viscous iron scales are difficult to remove. In the invention, the Ni content is 4.85-5.3%.
Al: as deoxidizing element, excessive aluminum is easy to lead Al in steel 2 O 3 The inclusion is increased to affect the low-temperature toughness of the steel, and Alt is controlled to be 0.02-0.05%.
Cr, cu, nb, ti: the content of the scrap steel added in smelting is not added, and the content control of the scrap steel is controlled to be less than or equal to 0.05 percent of Cr, less than or equal to 0.015 percent of Cu, less than or equal to 0.002 percent of Nb and less than or equal to 0.002 percent of Ti.
P, S, N: the impurity elements should be controlled in a low range as much as possible. In the invention, P is less than or equal to 0.008 percent, S is less than or equal to 0.003 percent and N is less than or equal to 0.005 percent.
And further preferably, the chemical components of the low-temperature steel billet are as follows by mass percent: mn=2si+0.05 to 0.22%, mn+si: 0.65-0.95%.
In the production method, the blank is subjected to a surface treatment, heating, hot rolling, cooling and heat treatment process to prepare a steel plate finished product with the thickness of 8-50 mm. Wherein, for the steel plate finished product with the thickness of 8-12 mm, blanks with the thickness of 80-120 mm can be adopted; for the steel plate finished product with the thickness of more than 12mm, a blank with the thickness of 220-250 mm can be adopted.
In the surface treatment step, the blank is first subjected to surface grinding, and then, a paint is applied to the surface of the ground blank, wherein the paint has the components as described in the embodiment of the present invention, and the specific application mode is also preferably as described in the embodiment of the present invention.
In the heating procedure, after the blank is coated with the coating, the blank enters a heating furnace to be heated at a high temperature, and the temperature of a soaking section is 1160-1200 ℃.
Preferably, in an embodiment that the thickness k of the steel plate finished product is 12mm less than or equal to k mm less than or equal to 50mm, the temperature of the soaking section is 1170-1200 ℃, and the heating time t in the furnace is 380-420 min; it will be appreciated that in the preceding surface treatment step, the overall number of coating applications and/or the coating thickness H of the coating application is controlled in accordance with the furnace duration t.
In another preferred embodiment, in the embodiment that the thickness k of the steel plate finished product is k mm < 12mm, the temperature of the soaking section is 1160-1180 ℃, the heat preservation time of the soaking section is 60-80 min, and the heating time t is 80-120 min; it will be appreciated that in the preceding surface treatment step, the overall number of coating applications and/or the coating thickness H of the coating application is controlled in accordance with the furnace duration t.
Then, after the blank is discharged from the heating furnace and before entering the roller way, the roller way water between the heating furnace and the rough descaling machine is closed in advance; then rough descaling is carried out at the rough descaling machine of the blank advancing path, and fine descaling is carried out at the inlet of the rolling mill; finally, the hot-rolled steel sheet enters a rolling mill to carry out a hot rolling process so as to roll the hot-rolled steel sheet with the thickness k.
In a preferred embodiment, the hot rolling process is carried out by single-stage rolling to obtain a hot rolled steel plate with the thickness k of 8mm less than or equal to k mm less than 12mm, and the specific process comprises the following steps: performing high-pressure water descaling after the first pass and three passes of rolling, wherein the descaling water pressure is more than or equal to 22MPa; of course, intermittent fine descaling can be performed according to the condition of the oxide skin on the surface of the steel plate, for example, high-pressure water descaling can be performed before five passes if needed; the initial rolling temperature is 1050-1100 ℃ and the final rolling temperature T fr +100 to 120 ℃; preferably, in the first 5 passes, the reduction of at least 3 passes is more than 16mm, and the single pass reduction is 10-35%. Thereafter, use is made ofAn Accelerated cooling control system (English full name Accelerated-cooling ControlSystem, ACC for short) is used for cooling the hot rolled steel plate, and the water inlet temperature T is fc The cooling speed is (25+1.5 k) +/-1.5 ℃/s, and the final cooling temperature is less than or equal to 200 ℃. And preferably, the redback temperature is less than or equal to 300 ℃, and the steel plate can be straightened after cooling. After the steel plate is cooled, firstly performing shot blasting at the speed of 0.06-0.1 m/s, and then performing tempering treatment, wherein the tempering temperature is Ac 1 -50~60℃，Ac 1 =T fc The tempering heat preservation time is at least 30min and is preferably [ (2.0-3.0) k at the temperature of 200-220 DEG C]And (5) min, air cooling after the steel plate is taken out of the tempering furnace, and obtaining a steel plate finished product.
In another preferred embodiment, the hot rolling process is to obtain a hot rolled steel plate with a thickness k of 12 mm.ltoreq.k mm.ltoreq.50 mm by two-stage rolling, and the specific process includes: performing high-pressure water descaling before the first pass and the third pass of rolling in the first stage, wherein the descaling water pressure is more than or equal to 22MPa; of course, intermittent fine descaling can be performed according to the condition of the oxide skin on the surface of the steel plate, for example, high-pressure water descaling can be performed before five passes if needed; the initial rolling temperature of the first-stage rolling is 1050-1100 ℃, the first-pass rolling reduction of the first-stage rolling is more than or equal to 15%, and the total rolling reduction is 53-79%; the total rolling reduction of the second stage rolling is more than or equal to 49 percent.
Preferably, for a hot rolled steel sheet having a thickness k of 12mm or less and k mm or less and 40mm or less, the second stage rolling is performed at a start rolling temperature of 890 to 940 ℃ and a finish rolling temperature T fr 20 ℃. After the hot rolled steel sheet is discharged from the rolling mill, it is cooled by air cooling. After air cooling, firstly performing shot blasting at the speed of 0.06-0.1 m/s, then performing quenching treatment and tempering treatment successively, wherein the quenching temperature is Ac 3 +30~50℃，Ac 3 =T fr -60-90 ℃ and tempering temperature of Ac 1 -50~80℃，Ac 1 =T fc The heat preservation time of quenching and tempering are respectively [ (2.0-3.0) k at the temperature of 200-220 DEG C]And (5) min, air cooling after the steel plate is taken out of the tempering furnace, and obtaining a steel plate finished product.
Preferably, for a hot rolled steel sheet with a thickness k of 40mm < k mm < 50mm, the initial rolling temperature 820-860 ℃ and the final rolling temperature T of the second stage rolling fr 10 ℃. After the hot rolled steel plate leaves the rolling mill, an accelerated cooling control system is adopted for cooling, and water is addedTemperature T fc Cooling speed (25+0.5k) +/-1.5deg.C/s at 10 ℃ and final cooling temperature less than or equal to 200deg.C. And preferably, the redback temperature is less than or equal to 300 ℃, and the steel plate can be straightened after cooling. Then, firstly performing shot blasting at the speed of 0.06-0.1 m/s, and then performing quenching treatment and tempering treatment successively, wherein the quenching temperature is Ac 3 -50~90℃，Ac 3 =T fr -60-90 ℃ and tempering temperature of Ac 1 -70~80℃，Ac 1 =T fc The heat preservation time of quenching and tempering are respectively [ (2.0-3.0) k at the temperature of 200-220 DEG C]And (5) min, air cooling after the steel plate is taken out of the tempering furnace, and obtaining a steel plate finished product.
Wherein T is fr =902-98C+47Si-10Mn-9.7Ni+95Cr-24Cu-115Ti+223Nb-202Al，T fc =784+117c+28si-10mn+11ni-126 Cr-34Cu-131ti+357nb-173Al, wherein the symbol of the element represents 100 times of the mass percentage of each element in the low-temperature billet.
Compared with the prior art, the production method of the low-temperature steel plate, disclosed by the embodiment, has the advantages that before the low-temperature steel billet is heated, the coating is coated on the surface of the low-temperature steel billet, so that the surface high-temperature oxidation resistance protection is carried out on the low-temperature steel billet, the problem of surface quality defect caused by high-temperature oxidation of the low-temperature steel billet is solved, the improvement of mechanical property and low-temperature toughness due to the influence of the surface quality is avoided, and therefore, the mechanical property and low-temperature toughness of a finished steel plate product are improved through the control of heating, hot rolling and heat treatment.
The low-temperature steel plate finished product prepared by the production method of the embodiment has the tensile strength of 600-710 MPa, the yield strength of 400-710 MPa, the elongation rate of more than or equal to 25%, the impact at minus 135 ℃ of more than or equal to 230J and the surface quality of excellent.
The method for producing the low-temperature steel sheet according to one embodiment is described above, and specific examples are provided below.
First, billets having the thicknesses and chemical compositions shown in table 4 were prepared. The preparation process of the steel billet A1 is approximately molten iron pretreatment-converter smelting-LF refining-RH refining-continuous casting-cogging, and the preparation processes of the steel billets A2 and A3 are approximately molten iron pretreatment-converter smelting-LF refining-RH refining-continuous casting.
TABLE 4
Carrying out surface grinding on each billet, and then respectively spraying the coating 1 in the table 1 on the ground surface by adopting the coating mode provided by the invention; next, a steel sheet finished product was produced using the production method described in one embodiment of the present invention, wherein important parameters of the heating process, the hot rolling process, the cooling process, and the heat treatment process are shown in table 5, and the "two-start temperature" in table 5 refers to the start rolling temperature of the second stage rolling.
TABLE 5
[ Table 5 continuation ]
The steel plate finished products prepared by each steel billet are sampled by using GB/T15125-2009 test sample and test method for metallographic examination of metal materials, and then the first part of the tensile test of the metal materials is carried out according to GB/T228.1-2021: the room temperature test method detects mechanical properties, the GB/T229-2007 Charpy pendulum impact test method for metal materials detects low-temperature toughness, the detection results are shown in Table 6, and the surface quality metallographic structure detection is performed, so that the surface quality, mechanical properties and low-temperature toughness of each steel plate finished product are excellent.
TABLE 6
Claims (10)
1. The high-temperature antioxidation coating for the steel billet is characterized by comprising a component A and a solvent;
the component A comprises: 30-60 parts by weight of SiO 2 3-20 parts by weight of Al 2 O 3 5-18 parts by weight of ZrO 2 1 to 12 parts by weight of SiC,1 to 8 parts by weight of C and 1 to 3 parts by weight of B 4 C, 2-16 parts by weight of a binder;
the weight of the solvent is 0.25-0.4 times of the weight of the component A.
2. The high-temperature oxidation-resistant coating for steel billets according to claim 1, wherein the component a further satisfies, in parts by weight: al (Al) 2 O 3 =(0.1~0.4)SiO 2 ，ZrO 2 = (1 to 1.5) SiC and sic+c+b 4 C=3~23。
3. The high-temperature oxidation-resistant coating for steel billets as claimed in claim 1, wherein the binder has a composition of K 2 SiO 3 Or Na (or) 5 P 3 O 10 。
4. The high-temperature oxidation-resistant coating for steel billets as claimed in claim 1, wherein the solvent is water.
5. A method of coating a billet with a high temperature oxidation resistant coating according to any one of claims 1 to 4, wherein the coating is sprayed onto the surface of the billet using a spray gun having a caliber of 0.3 to 1.5 mm;
wherein, one-time comprehensive spraying is finished through multiple passes;
in each spray coating pass, the air pressure of the spray gun is 0.5-0.8 MPa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between the nozzle and the surface of the steel billet is 20-35 cm, and the spray width is 20-45 cm;
and starting from the 2 nd pass, the spray width sprayed in each pass is overlapped with 30-40% of the spray width sprayed in the previous pass.
6. The method of coating a billet with a high-temperature oxidation-resistant coating according to claim 5, wherein the thickness of the coating sprayed on the whole surface each time is 0.2-0.3 mm.
7. The method of coating a billet with a high temperature oxidation resistant coating according to claim 6, further comprising:
obtaining the heating time t of the steel billet in the furnace, and finishing spraying after finishing one-time comprehensive spraying on the surface of the steel billet when t is less than or equal to 400 min; when t is more than 400min, finishing the spraying after finishing n=ceil ((t-400 min)/30 min) times of full spraying on the surface of the steel billet.
8. The method of coating a billet with a high temperature oxidation resistant coating according to claim 7, wherein when t > 400min, the time interval between any two full spray is not less than 15min.
9. The method of coating a billet with a high temperature oxidation resistant coating according to claim 5, wherein the billet after finishing the spraying is air-dried in an atmosphere of a temperature T ℃ and a relative humidity P%, and the air-drying period is not less than (0.075P x T) 0.5 +10~15)min。
10. A coating method of the high-temperature oxidation-resistant coating for the steel billet according to any one of claims 1 to 4, characterized in that the coating method adopts a spray gun with caliber of 0.3-1.5 mm, the coating is sprayed on the surface of the steel billet, the air pressure of the spray gun is 0.5-0.8 mpa, the spray angle is 25-40 ℃ with the surface of the steel billet, the distance between a nozzle and the surface of the steel billet is 20-35 cm, the spray width is 20-45 cm, and the superposition ratio of two adjacent spray widths is 30-40%;
when the heating time t of the steel billet is less than or equal to 400min, the thickness H of the paint sprayed on the surface of the steel billet is 0.2-0.3 mm;
when the heating time t of the steel billet is more than 400min, the thickness H of the paint sprayed on the surface of the steel billet is (0.2-0.3 mm) x ceil ((t-400 min)/30 min).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410263404.3A CN117844280A (en) | 2024-03-08 | 2024-03-08 | High-temperature antioxidant coating for steel billets and coating method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410263404.3A CN117844280A (en) | 2024-03-08 | 2024-03-08 | High-temperature antioxidant coating for steel billets and coating method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117844280A true CN117844280A (en) | 2024-04-09 |
Family
ID=90543775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410263404.3A Pending CN117844280A (en) | 2024-03-08 | 2024-03-08 | High-temperature antioxidant coating for steel billets and coating method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117844280A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101058684A (en) * | 2006-04-21 | 2007-10-24 | 中国科学院过程工程研究所 | High temperature common mild steel anti-oxidation coating and application thereof |
| CN101693791A (en) * | 2009-11-02 | 2010-04-14 | 北京科技大学 | Continuous casting slab high-temperature oxidation resistant coatings and preparation process thereof |
| CN110591423A (en) * | 2019-10-09 | 2019-12-20 | 东北大学 | Anti-oxidation coating applied to hot working of 9CrMoCoB steel and use method |
| CN111499395A (en) * | 2020-04-24 | 2020-08-07 | 北京天力创玻璃科技开发有限公司 | Metal high-temperature protective coating and metal high-temperature protective method |
| CN111607257A (en) * | 2020-05-22 | 2020-09-01 | 唐山元力科技有限公司 | Decarburization-resistant protective coating in spring steel billet heating process and application thereof |
| CN117511260A (en) * | 2023-11-01 | 2024-02-06 | 北京首钢股份有限公司 | Oriented billet decarburization-preventing coating, coating and preparation method thereof |
-
2024
- 2024-03-08 CN CN202410263404.3A patent/CN117844280A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101058684A (en) * | 2006-04-21 | 2007-10-24 | 中国科学院过程工程研究所 | High temperature common mild steel anti-oxidation coating and application thereof |
| CN101693791A (en) * | 2009-11-02 | 2010-04-14 | 北京科技大学 | Continuous casting slab high-temperature oxidation resistant coatings and preparation process thereof |
| CN110591423A (en) * | 2019-10-09 | 2019-12-20 | 东北大学 | Anti-oxidation coating applied to hot working of 9CrMoCoB steel and use method |
| CN111499395A (en) * | 2020-04-24 | 2020-08-07 | 北京天力创玻璃科技开发有限公司 | Metal high-temperature protective coating and metal high-temperature protective method |
| CN111607257A (en) * | 2020-05-22 | 2020-09-01 | 唐山元力科技有限公司 | Decarburization-resistant protective coating in spring steel billet heating process and application thereof |
| CN117511260A (en) * | 2023-11-01 | 2024-02-06 | 北京首钢股份有限公司 | Oriented billet decarburization-preventing coating, coating and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106350731B (en) | A kind of cold rolling high strength steel plate and its manufacturing method with excellent phosphorus characteristic and formability | |
| CN104611658B (en) | Annealing method for TA3 titanium plate prepared by roll-type production process | |
| EP4206352A1 (en) | Production method for non-oriented silicon steel, and non-oriented silicon steel | |
| CN105154784B (en) | A kind of high phosphorus weather-proof structural steel plate and preparation method thereof | |
| CN112322995B (en) | Low-yield-ratio high-toughness TMCP (thermal mechanical control processing) type bridge steel plate and production method thereof | |
| CN114480806B (en) | Manufacturing method of thick TiC particle enhanced martensite wear-resistant steel plate | |
| CN106381454A (en) | Piston rod of closed mold height measuring device and heat treatment technology of piston rod | |
| CN110699589A (en) | Preparation method of 301L stainless steel | |
| CN104988406A (en) | 355Lblack surface steel for automobile frame and production method for 355L black surface steel | |
| CN117844280A (en) | High-temperature antioxidant coating for steel billets and coating method thereof | |
| CN116837296A (en) | Preparation method and application of anti-oxidation hot forming steel suitable for thick specification | |
| CN117844281A (en) | High-temperature antioxidant coating for steel billets, and preparation method and application thereof | |
| CN115927954A (en) | Method for improving impact toughness of weathering resistant steel | |
| CN115216683A (en) | Method for regulating and controlling ferrite form in casting blank tissue and prepared microalloyed steel | |
| CN113355605A (en) | N550CF steel plate with low welding crack sensitivity and low-cost manufacturing method thereof | |
| CN118064691A (en) | Production method of low-temperature steel plate for ship storage | |
| CN112474825A (en) | Method for controlling surface cracks of 316LN nuclear power steel in rolling process | |
| CN106636965A (en) | Iron-cobalt-nickel alloy cold rolling strip with grain size number of grade 6-9 and production method thereof | |
| CN106676398B (en) | The nitrogen atmosphere corrosion resistance structural steel molten steel of titanium containing vanadium and atmosphere corrosion resistance structural steel and its production method | |
| CN106676402B (en) | The atmosphere corrosion resistance structural steel molten steel of titanium containing chromium and atmosphere corrosion resistance structural steel and its production method | |
| CN106676428B (en) | Atmosphere corrosion resistance structural steel molten steel and the atmosphere corrosion resistance structural steel of nitrogen containing niobium and its production method | |
| CN109881172A (en) | A kind of metal composite oxide target material and its processing method | |
| CN106676417B (en) | The atmosphere corrosion resistance structural steel molten steel of nitrogen containing vanadium and atmosphere corrosion resistance structural steel and its production method | |
| CN117604223B (en) | Production method of low-cost 370 MPa-level weather-resistant bridge steel plate | |
| WO2024040761A1 (en) | Production method for high-strength, high-toughness and weather-resistant bridge steel plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |