CN114934248B - Production method of hot-base galvanized plate for refrigerator slide rail - Google Patents
Production method of hot-base galvanized plate for refrigerator slide rail Download PDFInfo
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- CN114934248B CN114934248B CN202210328971.3A CN202210328971A CN114934248B CN 114934248 B CN114934248 B CN 114934248B CN 202210328971 A CN202210328971 A CN 202210328971A CN 114934248 B CN114934248 B CN 114934248B
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 38
- 238000005096 rolling process Methods 0.000 claims abstract description 58
- 238000000034 method Methods 0.000 claims abstract description 35
- 238000005554 pickling Methods 0.000 claims abstract description 24
- 238000010438 heat treatment Methods 0.000 claims abstract description 23
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 20
- 239000010959 steel Substances 0.000 claims abstract description 20
- 238000009749 continuous casting Methods 0.000 claims abstract description 19
- 230000008569 process Effects 0.000 claims abstract description 19
- 239000002253 acid Substances 0.000 claims abstract description 15
- 238000005246 galvanizing Methods 0.000 claims abstract description 13
- 238000002161 passivation Methods 0.000 claims abstract description 11
- 238000005498 polishing Methods 0.000 claims abstract description 10
- 238000005406 washing Methods 0.000 claims abstract description 10
- 238000009628 steelmaking Methods 0.000 claims abstract description 9
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 5
- 239000011574 phosphorus Substances 0.000 claims abstract description 5
- 238000007747 plating Methods 0.000 claims description 21
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 16
- 239000011701 zinc Substances 0.000 claims description 16
- 229910052725 zinc Inorganic materials 0.000 claims description 16
- 230000006698 induction Effects 0.000 claims description 11
- 239000000758 substrate Substances 0.000 claims description 10
- 238000002791 soaking Methods 0.000 claims description 6
- 238000010583 slow cooling Methods 0.000 claims description 5
- 238000003723 Smelting Methods 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 4
- 239000003930 superacid Substances 0.000 claims description 2
- 230000001050 lubricating effect Effects 0.000 claims 1
- 239000000047 product Substances 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 9
- 238000001556 precipitation Methods 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 238000005266 casting Methods 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 230000007547 defect Effects 0.000 description 5
- 238000005098 hot rolling Methods 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 230000003746 surface roughness Effects 0.000 description 5
- 239000010936 titanium Substances 0.000 description 5
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 238000007664 blowing Methods 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 230000032683 aging Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 238000010079 rubber tapping Methods 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 238000009489 vacuum treatment Methods 0.000 description 2
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- 229910000997 High-speed steel Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000002500 effect on skin Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000008397 galvanized steel Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000008237 rinsing water Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
- B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
- C22C18/04—Alloys based on zinc with aluminium as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- 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
- C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
- C23C2/36—Elongated material
- C23C2/40—Plates; Strips
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Coating With Molten Metal (AREA)
Abstract
The invention discloses a production method of a hot-base galvanized plate for a refrigerator slide rail, which belongs to the technical field of steel production, and comprises the following process flow routes: steelmaking, continuous casting, hot continuous rolling, continuous pickling and galvanizing; continuous pickling and galvanization: comprises the steps of drawing and straightening, phosphorus breaking, acid washing, rinsing, heating, galvanization, polishing, passivation and drawing and straightening. The product performance yield strength after galvanization is less than or equal to 290MPa, the tensile strength is less than or equal to 400MPa, the elongation is more than or equal to 31 percent, and the stamping forming requirement of the refrigerator slide rail is met.
Description
Technical Field
The invention relates to the technical field of steel production, in particular to a production method of a hot-base galvanized sheet suitable for a refrigerator slide rail.
Background
The refrigerator slide rail is divided into an outer rail, a middle rail and an inner rail, and galvanized plates with thickness of 1.0mm-2.0mm and thickness tolerance of +/-0.04 mm are mainly used. The surface quality requirement is high, and the galvanized surface cannot have defects of zinc flow marks, chromatic aberration, scratches and the like; the ball type sliding rail reduces the noise requirement, and the surface roughness is less than 1.0 mu; the yield strength is 260-300Mpa, the tensile strength is 360-420Mpa, the elongation is 30-39%, the hardness is 66-73HRB, and the requirements of sliding rail molding and wear resistance are met.
At present, cold-base zinc plating is generally adopted in the industry to prepare the sliding rail, but based on the original purpose of energy conservation and emission reduction, the use of hot-base zinc plating plates to replace cold-base zinc plating is continuously explored in the field of sliding rails in recent years. As stated in the company, the method (CN 202110116290.6) for manufacturing 500 MPa-level seat slide rail steel based on continuous casting and rolling line is used for producing 1.5-3.0mm hot base plates, and can realize thin specifications of 2.0mm and below. However, the method can only produce the sliding rail of the automobile seat, the yield strength is more than or equal to 500MPa, the tensile strength is more than or equal to 600MPa, and the elongation after break A80 is 17-19%; a zinc-flower-free hot-dip galvanized sheet process (CN202010246403. X) is used for producing a galvanized sheet with a grid of 1.2-4.0mm, wherein the product performance yield strength is more than or equal to 350MPa, the tensile strength is more than or equal to 420MPa, and the elongation is more than or equal to 14%. The reason is that the recrystallization annealing process is not used in the hot base galvanizing production process, the strength is higher after the galvanizing process due to factors such as precipitation strengthening, dislocation strengthening and the like, the yield strength cannot be reduced to below 300Mpa, the elongation is generally less than 30%, the surface roughness is 0.8-1.2 mu, the processability is deviated, chromatic aberration and bright spots exist on the galvanized surface, the surface of the colder base galvanizing is poor, and the performance and the surface parameters cannot be applied to refrigerator slide rails in the home appliance industry. And the thickness tolerance is +/-0.09 mm, so that the stability of the thickness tolerance is poor, and the mass production cannot be realized.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a production method of a hot-base galvanized plate for a refrigerator slide rail, aiming at a hot-base galvanized product with a thin specification of 2.0mm or below, the production of a common stamping grade hot-dip galvanized product is realized by optimizing the substrate component design and hot rolling and galvanization processes, controlling aging, organization and precipitation strengthening, the requirements of forming and surface quality of a galvanized stamping plate for the refrigerator slide rail are met, and the cold-base product is replaced in the household slide rail industry, so that the cost and consumption are reduced.
The technical scheme for solving the technical problems is as follows: a production method of a hot-base galvanized sheet for a refrigerator slide rail comprises the following process flow routes: steelmaking, continuous casting, hot continuous rolling, continuous pickling and galvanizing; the method is characterized by comprising the following steps of:
S1: steelmaking;
s2: continuous casting: smelting to obtain molten steel with required components;
S3: hot continuous rolling: the method comprises rough rolling, induction heating, high-pressure descaling, and finish rolling; wherein the finish rolling adopts a polishing frame for rolling and lubrication rolling, and the finishing rolling temperature is 870-910 ℃;
S4, continuous pickling and galvanization: comprises the steps of drawing and straightening to break phosphorus, acid washing, rinsing, heating, galvanization, finishing, passivation and drawing and straightening; wherein, the substrate is in a super-acid washing state in the acid washing process; in the heating process, the temperature after induction heating is 530-550 ℃, the temperature of a soaking slow cooling rear plate is 485-490 ℃, and the temperature of a zinc pot plate is 462-467 ℃; the elongation of the withdrawal and straightening breaker is 0.2-0.4%, the elongation of the finishing machine after plating is 0.7-0.9%, the elongation of the withdrawal and straightening machine is 0.2-0.3%, and the total elongation is 1.4+/-0.2%.
Further, the continuous casting tundish molten steel comprises the following components: c is less than or equal to 0.008 percent, si:0.04 to 0.05 percent; mn:0.06-0.10%; s: less than or equal to 0.003%; p: less than or equal to 0.015 percent; ti:0.015 to 0.020 percent; n: less than or equal to 0.003 percent, and the balance of Fe element and unavoidable impurities.
Further, the rolling of the polishing frame is changed from 5 rolling mills to 4 rolling mills.
Further, the pickling parameters in the pickling process are that the free acid concentration of the pickling tank is 90g/L-100g/L, and the pickling temperature is 80-95 ℃.
Further, the elongation sum of the post-plating finishing and withdrawal and straightening machine is 0.9-1.3%.
Further, the elongation sum of the post-plating finishing and withdrawal and straightening machine is 1.1+/-0.1%.
Further, the post-plating finishing adopts a finishing roller as a smooth roller.
Further, the original roughness of the roller surface of the smooth roller is 0.3-0.5 mu.
Further, the passivation is a chromate-free passivation.
Compared with the prior art, the invention has the following outstanding beneficial effects:
1. the production method for producing the hot-base galvanized plate for the refrigerator slide rail by the continuous pickling galvanization production line is provided, the binding force of a plating layer is excellent, the surface quality is equivalent to that of cold-base galvanization, the surface roughness of a smooth surface galvanization product is 0.3-0.6 mu, and the surface quality of the product is good;
2. The strength of the hot-base galvanized sheet is reduced, the elongation of the hot-base galvanized sheet is improved, the yield strength of the galvanized product performance is less than or equal to 290MPa, the tensile strength is less than or equal to 400MPa, the elongation is more than or equal to 31%, and the stamping forming requirement of the sliding rail of the refrigerator is met;
3. The steel for the refrigerator slide rail with the thickness specification of 1.0mm-2.0mm is produced, the performance and the dimensional deviation are stable, and the thickness tolerance is controlled to be +/-0.03 mm.
Detailed Description
The invention is further described below in connection with the following detailed description.
The invention provides a production method of a hot-base galvanized sheet for a refrigerator slide rail, which adopts a continuous pickling and galvanization combined unit to produce the hot-base galvanized sheet for the refrigerator slide rail. The method can be disassembled into two steps, firstly, the hot-base galvanized raw materials produced on the continuous hot rolling production line are used, then the hot-base galvanized raw materials enter a galvanization procedure for production, and finally, the hot-base galvanized sheet for the refrigerator slide rail is obtained.
The technical scheme of the invention comprises the following components in percentage by weight: c is less than or equal to 0.008 percent, si:0.04 to 0.05 percent; mn:0.06-0.10%; s: less than or equal to 0.003%; p: less than or equal to 0.015 percent; ti:0.015 to 0.020 percent; n: less than or equal to 0.003 percent. The balance of Fe element and unavoidable impurities.
Key component control C, ti control description of the invention:
c: the carbon element can be dissolved in the steel to form solid solution, which can play the role of solid solution strengthening, but the plasticity and the welding performance are reduced along with the increase of the carbon content; conversely, reducing the carbon content may increase the plasticity of the steel. To obtain higher elongation hypoeutectoid steels. The C content is controlled to be less than or equal to 0.008 percent in the invention. The C content is controlled to be less than or equal to 0.008 percent and exceeds the expectation, and the control of the end point C and tapping temperature of the converter, the vacuum treatment of an RH furnace and the application of a non-destructive electrode of an LF furnace are combined.
Ti: titanium is a strong carbonitride forming element in steel, and liquid precipitation and solid precipitation of TiN and Ti 4C2S2 particles occur in the continuous casting and cooling stages; in the rolling stage, deformation induction precipitation of TiC in austenite occurs; precipitation of TiC also occurs during the cooling and winding stages. The addition of Ti content can effectively inhibit the aging of steel. The Ti content in the invention is controlled to be 0.015-0.020%.
The relation of C, ti quantities in the present invention has the requirement: and when C is more than or equal to 0.01, the rest part easily causes part of TiC to be precipitated and strengthened, which is not beneficial to reducing the strength and the stamping formability of the steel plate.
The invention relates to a process mode for producing hot-base galvanized raw materials by adopting a continuous casting and rolling mode, which comprises the following steps: steelmaking, continuous casting, rough rolling, induction heating, high-pressure descaling, finish rolling, laminar cooling and coiling. Finally obtaining the hot-base zinc plating raw material with the thickness of 1.0-2.0 mm.
The process comprises the following steps:
S1: steelmaking
The method specifically comprises the following steps: converter-LF furnace treatment-RH vacuum furnace treatment.
And (3) a converter: the end point C is 0.030-0.060, the tapping oxygen is 550-800ppm, and the tapping temperature is more than or equal to 1630 ℃;
LF furnace: checking the electrode before LF treatment, using the electrode without cracks and breakage, and controlling the power transmission time to be less than or equal to 20min and the temperature: LF refining outlet is controlled according to 1640-1650 ℃.
RH vacuum furnace treatment: RH arrival temperature: not less than 1635 ℃; the standing slag thickness is less than or equal to 200mm. And (3) starting oxygen blowing and decarburization after vacuum circulation for 3min, calculating oxygen blowing amount according to the entering sample C, and finishing oxygen blowing once and oxygen fixing for 3min after oxygen blowing starts. The vacuum degree is less than or equal to 2mbar (the pressure after a vacuum valve), and the holding time is more than or equal to 6 minutes; vacuum treatment time: and not less than 20min. Before aluminum addition and deoxidation: [C] less than or equal to 20ppm, [ O ] =200-350 ppm.
S2: continuous casting
Continuous casting tundish covering agent: the lower layer adopts a high-alkalinity low-carbon covering agent, and the (FeO+MnO) is less than or equal to 3 percent; crystallizer casting powder: and (5) low-carbon covering slag. Molten steel with required components is obtained through smelting, and the continuous casting tundish components and the design range are (wt%): c is less than or equal to 0.008 percent, si:0.04 to 0.05 percent; mn:0.06-0.10%; s: less than or equal to 0.003%; p: less than or equal to 0.015 percent; ti:0.015 to 0.020 percent; n: less than or equal to 0.003 percent. The balance of Fe element and unavoidable impurities.
The casting speed is high, the efficiency is high, which is one of the most main characteristics of a short-flow production line, the pulling speed is too high, the temperature of a rolling line is high, and the surface oxidation control difficulty is high; the casting pulling speed is slow, the temperature drop in the production process is large, the rolling load is increased, and the final rolling temperature is difficult to ensure. Therefore, the casting pulling speed is controlled to be 5.3-5.6 m/min.
Molten steel obtained by smelting enters a continuous casting machine to obtain a casting blank;
S3: hot continuous rolling
The method specifically comprises the following steps: rough rolling, induction heating, high-pressure descaling and finish rolling.
Rough rolling: the casting blank is directly hot rolled without heating by a soaking pit, the temperature of a hot rolling rough rolling inlet is increased to 990-1020 ℃, and a rough rolling outlet is ensured to be 980-1000 ℃.
Finish rolling:
(1) Adopting a polishing frame for rolling, specifically changing the finish rolling from 5 rolling mills to 4 rolling mills (polishing F5);
(2) The actual finishing temperature (F4 outlet) is 870-910 ℃. The final rolling temperature is increased by 40-50 ℃ compared with the conventional endless rolling, and the aim is to avoid rolling in a two-phase zone;
(3) The working roll of the hot rolling finishing mill adopts a high-speed steel roll, the rolling mileage is less than or equal to 110KM, and the surface of the substrate is controlled to have no bright spots and color difference;
(4) The rolling lubrication is adopted, the average rolling force 25000KN of the thin specification below 1.2mm is reduced to 19000-21000KN, the average rolling force of 1.0-2.0mm is reduced by 15-20%, and the rolling force load of the headless rolling thin specification finishing mill is controlled.
S4: layer-cooled rolling
The laminar cooling is changed into the post-stage cooling, and the high-temperature coiling is used for ensuring the full growth of crystal grains and the precipitation of solid solution after finish rolling, further improving the toughness of the product and reducing the aging, and the coiling temperature is 700-720 ℃.
The hot rolled strip steel used as the galvanized base material has the flatness of less than or equal to 200I and 1.0-2.0mm, and the defects of iron oxide scale pits and the like cannot be caused. And then the hot-base galvanized raw material enters a galvanization procedure to be produced, and finally the hot-base galvanized sheet with the thickness of 1.0-2.0mm for the refrigerator slide rail is obtained.
Another mode of the invention is to directly produce the hot-base galvanized sheet for the refrigerator slide rail by adopting a continuous casting and rolling production line and a continuous pickling and galvanizing combined unit (PGL), and mainly utilizes steelmaking, continuous casting, continuous rolling and PGL galvanizing. PGL galvanization comprises the steps of carrying out withdrawal and straightening, phosphorus breaking, acid washing, rinsing, heating, galvanization, finishing, passivation, withdrawal and straightening and coiling through a continuous acid washing galvanization production line to produce hot galvanizing coiled plates. The hot galvanizing production can be directly carried out by the hot rolling target thickness without cold rolling and continuous annealing processes, so that the hot galvanizing production is realized, and considerable economic benefit and great social significance are realized.
S1, steelmaking: as above.
S2, continuous casting: as above.
S3, hot continuous rolling: as above.
S4, continuous pickling galvanization
And (3) feeding the strip steel obtained in the step (S3) into a PGL acid plating continuous production line, and carrying out withdrawal and straightening phosphorus breaking, acid washing, rinsing, heating, galvanization, finishing, passivation, withdrawal and straightening and coiling to obtain the hot-base galvanized coiled plate.
In the pickling process, the free acid concentration of an acid tank is 90g/L-100g/L, and the pickling temperature is 80-95 ℃; the rinsing water temperature is 45-55 ℃, and the conductivity is 30-50ms/cm. Compared with the conventional pickling method, the concentration of free acid is improved by 15-30g/L, the pickling temperature is 15-30 ℃, and the substrate is in a super-pickling state.
In the heating process, the temperature after induction heating is 530-550 ℃, the temperature of a soaking slow cooling rear plate is 485-490 ℃, the temperature of a zinc pot plate is 462-467 ℃, and the dew point of an induction heating furnace is: -50 ℃ or lower, furnace pressure: 0.4-1.0mbar, hydrogen content > 9%, ensuring the substrate to be fully reduced before plating. The induction heating has skin effect, the temperature of the substrate is uniform by increasing the heating hot-base galvanizing temperature by 30 ℃, the soaking slow cooling process is increased, the substrate surface quality and the adhesion of a galvanized coating after the galvanizing are ensured to be fully reduced, the soaking slow cooling process is increased, the substrate is ensured to be fully reduced, and the temperature of the plate entering a zinc pot is required to be controlled at a lower level.
The production line adopts a single flattening and double withdrawal and straightening process, and the scale breaking before pickling provides a good interface for cleaning the scale with acid liquor; and (5) before coiling, pulling and straightening to obtain a good plate shape. The specific parameters are as follows: the elongation of the withdrawal and straightening (descaling) machine is 0.2-0.4%, the elongation of the finishing machine after plating is 0.7-0.9%, the elongation of the withdrawal and straightening machine is 0.2-0.3%, and the total elongation is 1.4+/-0.2%. The leveling procedure is positioned before induction heating, the dislocation density is increased in a leveling way, solid solution interstitial atoms at interstitial positions are activated at a higher temperature in the heating process, the movement capability is greatly improved, and the solid solution interstitial atoms are gathered to the defect under the action of an dislocation stress field. Since the movement of the movable dislocations is hindered, a greater force must be applied to move the movable dislocations together with the interstitial free pinning or dragging, macroscopically representing an increase in yield strength. Therefore, the polishing is flat before heating, and the performance change caused by baking hardening can be controlled. The elongation of the finishing and straightening machine after plating is 0.9-1.3%, the optimization scheme is 1.1+/-0.1%, the pinning effect of the galvanized steel plate C, N is destroyed, the yield strength is reduced, and the rolling force 1000-1200KN requirement and the plate shape control requirement of the finishing and straightening roller are obtained.
In the zinc plating process, the zinc liquid in the zinc pot comprises the following components: zn > 99%, al:0.20-0.30%, sb less than or equal to 0.02%, fe less than or equal to 0.03%, and others less than or equal to 0.015%, and the temperature of zinc liquid is as follows: 460 ℃ +/-2 ℃.
The polishing roller is a smooth roller, the original roughness of the roller surface is 0.3-0.5 mu, and the surface roughness customization requirement of the refrigerator slide rail industry can be met.
The passivation adopts chromic acid-free passivation, thereby meeting the environmental protection requirement of household appliances.
In order to better compare the present application with the prior art, a comparative test was performed.
Examples 1-3 are the component designs of the present application and the technique of the present application for directly producing a hot base galvanized sheet for a refrigerator slide rail. Example 4 is the production of hot base galvanised raw material using continuous casting and rolling mode, rather than the final product.
The control group adopts the design of molten steel components in a 300 MPa-level low-carbon hot rolled steel production method (CN 202011195998.7) without transverse fold defects; combines the production process in the zinc flower-free hot galvanized sheet process (CN202010246403. X).
1. And (3) designing components of each group of galvanized substrates:
| Element(s) | C | Si | Mn | P | S | Ti | N | B |
| Example 1 | 0.0078 | 0.045 | 0.076 | 0.012 | 0.003 | 0.016 | 0.0013 | - |
| Example 2 | 0.0067 | 0.050 | 0.085 | 0.008 | 0.001 | 0.0180 | 0.0024 | - |
| Example 3 | 0.0080 | 0.043 | 0.068 | 0.015 | 0.001 | 0.0172 | 0.0030 | - |
| Example 4 | 0.0059 | 0.040 | 0.098 | 0.013 | 0.002 | 0.0168 | 0.0017 | - |
| Control group | 0.012 | 0.10 | 0.18 | 0.009 | 0.002 | - | 0.0050 | 0.002 |
2. The control of each set of production parameters is shown in the following table:
3. The parameter control of each group in terms of extension is shown in the following table: examples 1-3 are single leveling + double withdrawal processes, the control set is a double leveling set:
The comparison results are shown in the following table:
From the results, the method of the invention is used for directly producing the hot-base galvanized plate for the refrigerator slide rail in the embodiments 1-3, the binding force of the plating layer is excellent, the surface quality of the product is good, the yield strength of the galvanized product performance is less than or equal to 290MPa, the tensile strength is less than or equal to 400MPa, and the elongation is more than or equal to 31%; the surface quality is equivalent to that of cold base zinc plating, and the surface roughness of a smooth surface zinc plating product is 0.3-0.6 mu; the performance and the dimensional deviation are stable, and the binding force of the plating layer is excellent. The hot-base galvanized raw material with the thickness of 1.2mm obtained in the example 4 enters a traditional pickling galvanization production line, and cannot produce the hot-base galvanized sheet meeting the use specification of the refrigerator slide rail, wherein the yield strength is 290-350Mpa, the tensile strength is 360-420Mpa, and the elongation is 23-32%.
The low-strength component design and the thin plate galvanization method in the prior art are combined to obtain a control group, so that the hot-base galvanized sheet with the thickness of 1.2mm cannot be stably produced, the dimensional deviation is unstable, and the thickness tolerance reaches +/-0.06 mm. Moreover, the yield strength is 339MPa, the elongation is 27%, the slide rail is manufactured by stamping and formed, the part with larger deformation is easy to crack, the surface quality control result is unqualified, and the slide rail cannot be used as a refrigerator slide rail for production.
It is noted that while the present invention has been described in detail with respect to specific embodiments thereof, it will be apparent to those skilled in the art that various modifications can be made therein without departing from the spirit and scope thereof.
Claims (8)
1. A production method of a hot-base galvanized sheet for a refrigerator slide rail comprises the following process flow routes: steelmaking, continuous casting, hot continuous rolling, continuous pickling and galvanizing; the method is characterized by comprising the following steps of:
S1: steelmaking;
s2: continuous casting: smelting to obtain molten steel with required components; wherein, C is less than or equal to 0.008 percent, ti: 0.015-0.020%;
S3: hot continuous rolling: the method comprises rough rolling, induction heating, high-pressure descaling, and finish rolling; the finish rolling is carried out by adopting a polishing frame for rolling and lubricating and rolling, and the finishing temperature is 870-910 ℃;
s4, continuous pickling and galvanization: comprises the steps of drawing and straightening to break phosphorus, acid washing, rinsing, heating, galvanization, finishing, passivation and drawing and straightening; wherein, the substrate is in a super-acid washing state in the acid washing process; leveling before polishing and heating; in the heating process, the temperature after induction heating is 530-550 ℃, the temperature of a soaking slow cooling rear plate is 485-490 ℃, and the temperature of a zinc pot plate is 462-467 ℃; the elongation of the withdrawal and straightening breaker is 0.2-0.4%, the elongation of the finishing machine after plating is 0.7-0.9%, the elongation of the withdrawal and straightening machine is 0.2-0.3%, and the total elongation is 1.4+/-0.2%;
the product performance yield strength after galvanization is less than or equal to 290MPa, the tensile strength is less than or equal to 400MPa, and the elongation is more than or equal to 31%.
2. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the continuous casting tundish molten steel comprises the following components: c is less than or equal to 0.008 percent, si:0.04 to 0.05 percent; mn:0.06-0.10%; s: less than or equal to 0.003%; p: less than or equal to 0.015 percent; ti: 0.015-0.020%; n: less than or equal to 0.003 percent, and the balance of Fe element and unavoidable impurities.
3. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the polishing frame rolling is specifically that the finish rolling is changed from 5 rolling mills to 4 rolling mills.
4. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the pickling process has the pickling parameters of 90g/L-100 g/L free acid concentration in the pickling tank and 80-95 deg.c.
5. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the elongation sum of the post-plating finishing and withdrawal and straightening machine is 1.1+/-0.1%.
6. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the post-plating finishing adopts a finishing roller as a smooth roller.
7. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 6, characterized in that: the original roughness of the roller surface of the smooth roller is 0.3-0.5 mu m.
8. The method for producing a hot-base galvanized sheet for a refrigerator slide rail according to claim 1, characterized in that: the passivation adopts chromic acid-free passivation.
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