CN109161796B - High-strength beam steel 800L with good low-temperature impact toughness and production method thereof - Google Patents
High-strength beam steel 800L with good low-temperature impact toughness and production method thereof Download PDFInfo
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- 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
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
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- 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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
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- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- 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
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- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/004—Dispersions; Precipitations
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- 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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
Abstract
The invention discloses high-strength beam steel 800L with good low-temperature impact toughness and a production method thereof, wherein the high-strength beam steel 800L comprises the following chemical components in percentage by mass: c: 0.065-0.085%, Si: 0.05-0.15%, Mn: 1.30-1.60%, P is less than or equal to 0.014%, S is less than or equal to 0.003%, Nb: 0.045-0.065%, Ti: 0.100-0.120%, Als: 0.015-0.035%, N is less than or equal to 0.005%, and the balance is Fe and impurities within an allowable range; the production method comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling. The invention adopts the low-carbon high-manganese and small-amount niobium-titanium composite strengthening mechanism to ensure that the structure and the performance meet the requirements, and the rolling process adopts TMCP thermomechanical rolling to improve the comprehensive mechanical property of the steel.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to high-strength beam steel 800L with good low-temperature impact toughness and a production method thereof.
Background
800L belongs to high-strength automobile girder steel and is mainly used for processing commercial vehicle girders. With the rapid development of current automobile transportation and the strong implementation of national policy for overtaking. The light weight of the commercial vehicle is one of important measures for reducing haze and controlling environment in the field of automobiles, and has attracted extensive attention of the whole society.
The thicknesses of the automobile beam steel plates are respectively reduced by 0.05mm, 0.10mm and 0.15mm, the automobile body can be reduced by 6 percent, 12 percent and 18 percent, the strength of the steel plates is an important way for reducing the plate thickness, and the fuel consumption of the automobile can be reduced by 6 to 8 percent when 10 percent of the total weight of the automobile is reduced. Therefore, on the premise of ensuring the integral strength and the use reliability of the automobile, the weight of the automobile body is reduced, the oil consumption of the automobile can be reduced, and the cruising ability of the automobile is improved. The large load-bearing part inside the automobile bears almost all the weight of the automobile and goods, and directly influences the driving safety of the automobile, so that the deformation of the crossbeam is mainly bending.
The manufacturing process used by the steel plate of the automobile beam is a stamping and bending forming mode, the steel plate of the beam is also very high in requirement, and the later development trend is that two materials, namely, low-alloy high-strength and ultrahigh-strength steel plates, are required to be used.
With the vigorous implementation of the policy of limiting the load of the commercial vehicle and controlling the overload, the self weight of the commercial vehicle is reduced, the effective load is improved, the fuel consumption is reduced, and the like, which is a development trend for a long time in the future. At present, materials used for low-tonnage loads are Q345, 510L and 610L, so that the safety of the whole vehicle is guaranteed, the steel of key load-bearing parts is thicker, the weight of the vehicle is increased, and 700L with higher strength is used on commercial vehicles, special vehicles and engineering machinery vehicles at present. The development of automotive frame steel with higher strength is imperative from the viewpoint of economy and energy saving.
Disclosure of Invention
The invention aims to provide 800L high-strength beam steel with good low-temperature impact toughness and a production method thereof.
In order to solve the technical problems, the invention adopts the technical scheme that: 800L of high-strength beam steel with good low-temperature impact toughness, wherein the 800L of high-strength beam steel comprises the following chemical components in percentage by mass: c: 0.065-0.085%, Si: 0.05-0.15%, Mn: 1.30-1.60%, P is less than or equal to 0.014%, S is less than or equal to 0.003%, Nb: 0.045-0.065%, Ti: 0.100-0.120%, Als: 0.015-0.035%, N is less than or equal to 0.005%, and the balance is Fe and impurities within an allowable range.
The high-strength beam steel has the thickness specification of 800L of 2.0-16.0 mm, the metallographic structure of quasi-polygonal ferrite, acicular ferrite and TiC precipitate and the grain size of 11.5-13.0 grade.
The high-strength beam steel has the mechanical properties of 800L: the yield strength is 720-790 MPa, the tensile strength is 810-900 MPa, the elongation is 15-19%, the yield ratio is 0.92-0.96, and the impact energy of a full-size sample at-20 ℃ is 120-180J.
The invention also provides a production method of 800L of high-strength beam steel with good low-temperature impact toughness, which comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling; the rolling process is controlled, the first stage is rough rolling, the finish rolling temperature of the rough rolling is 1010-1060 ℃, the second stage is finish rolling, the finish rolling inlet temperature is controlled to be 1000-1050 ℃, the finish rolling temperature is controlled to be 886-914 ℃, and the coiling temperature is 583-617 ℃; in the laminar cooling process, a front-section 3/4 cooling mode is adopted in a laminar cooling stage, the temperature of cooling water is controlled to be 25-33 ℃, and the cooling speed is controlled to be 23-50 ℃/s.
According to the rolling procedure controlled, two-stage rolling is adopted, the first stage is rough rolling, 3+ 5-pass rolling is adopted, the finish rolling temperature of the rough rolling is 1010-1060 ℃, and the thickness of a rough rolling outlet intermediate blank is 36-50 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled to be 1000-1050 ℃, the steel is rolled for 7 times by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the last secondary reduction rate is 20-23%, the accumulated reduction rate of the second stage is 67-93%, the finish rolling finishing temperature is controlled to be 886-914 ℃, and the coiling temperature is 583-617 ℃.
According to the laminar cooling process, a front-stage 3/4 cooling mode is adopted in a laminar cooling stage, namely a group of 4 water headers is adopted, 3 headers are arranged in each group, and water consumption of each roll is 4200-5600 m for carrying out cultivation.
The molten iron pretreatment process of the invention is that molten iron after blast furnace smelting is poured into a ladle, a ladle enters a desulfurization station for desulfurization treatment, and the molten iron S before desulfurization is: 0.030-0.050%, adopting magnesium powder and lime for blowing and desulfurizing, wherein the molten iron S after desulfurization treatment in a desulfurization station is less than or equal to 0.008%; the ratio of the magnesium powder to the lime is controlled to be 2.5-3.0, the spraying time is controlled to be 24-30 min, the spraying rate of the magnesium powder is controlled to be 13.5-15.0 kg/min, and the spraying rate of the lime is controlled to be 36-41 kg/min.
The smelting process adopts the processes of converter smelting, LF refining and RH refining;
the converter smelting process comprises the steps of adopting a 250T converter for blowing, adding 40T of self-produced high-quality scrap steel (mainly low-carbon steel edge cutting plates) into 250T of molten iron per furnace, controlling the total loading amount within 300T, controlling the alkalinity of furnace slag in the furnace to be 3.0-4.5, controlling the oxygen blowing speed to be 11-12 m during power distribution/s, and controlling the total oxygen blowing time to be 900-1100 s; in order to prevent the increase of N in molten steel, argon is blown from the bottom of the converter in the whole blowing process for 200-350 NM/h; air is prevented from being sucked, and the micro positive pressure of the converter mouth of the converter is ensured to be 10-20 Pa in the blowing process; the end point blowing temperature of the converter is 1630-1660 ℃, and the end point C is controlled: 0.02-0.04%, P is less than or equal to 0.015%, O: 500 to 900 ppm; the method comprises the following steps of (1) stopping slag by using a sliding plate during tapping, strictly controlling the slag discharging amount, wherein the tapping time is 5-7 min, adding 11.5-12.5 kg/t of steel of electrolytic manganese alloy during tapping 1/4, adding lime during tapping 1/2, and adding the lime at an amount of 0.5-0.8 kg/t of steel;
the LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the materials enter a station to rapidly make white slag, the aluminum content of the materials entering the station is controlled to be 300-400 ppm, the materials are sampled and tested for components after the materials are formed into slag, and the alloy content of the molten steel is adjusted according to the components; the heating time of LF power transmission molten steel is controlled to be 15-20 min, the temperature rising speed is 5-6 ℃/min, the refining outlet temperature is controlled to be 1615-1640 ℃, the LF refining time is 35-55 min, Ca treatment is not carried out after refining is finished, and the net blowing Ar gas time is 6-10 min, so that the temperature of the molten steel is prevented from being reduced too much, and the net blowing gas amount is controlled well to prevent the molten steel from being exposed; in the whole refining process, except the alloying and S-removing process, large-gas-amount stirring is forbidden, and the micro-positive pressure operation in the furnace is carried out, so that the gas suction of molten steel is avoided;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas amount is 2000-3000 NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the vacuum degree of the vacuum tank is less than or equal to 1.0mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 20-25 min, and the pure degassing time is 6-10 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to the ground, controlling the flow at 300-800 NL/min, preferably micro-motion of the slag surface, and strictly prohibiting strong stirring; and performing Ca treatment when the molten steel reaches a wire feeding position, controlling the Ca content of the molten steel to be 20-30 ppm, and performing soft blowing for 6-8 min after the Ca treatment is finished.
In the continuous casting process, dynamic soft reduction is adopted, the reduction of the solidified tail end is increased, the reduction of the tail end is manually adjusted according to the pulling speed, the reduction is increased from 1.5mm to 2.0mm, and the center quality of a casting blank is improved; the continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled to be 0.9-1.4 m/min, the casting is carried out at a constant drawing speed, one sulfur sample is taken every time each casting time to test the internal quality of a casting blank, the continuous casting pouring time is 38-45 min, the slab end is cut to be 2.0-2.5 m, and the tail blank is cut to be 1.5-2.0 m; the weight of the tundish molten steel is 38-65 t, and the amount of the tundish residual steel is 18-25 t.
According to the casting blank heating process, the temperature of a heating section is 1230-1270 ℃, and the total heating time is 200-300 min.
The invention has good low-temperature impact toughness and high strength beam steel 800L product standard reference GB/T3273-2015; the product performance detection method is in standard reference GB/T228/229/232.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: 1. the invention adopts the mechanism of low-carbon high-manganese and small amount of niobium-titanium composite reinforcement in component design, and ensures that the structure and the performance meet the requirements by the fine-grain reinforcement of Nb and Ti alloys and the precipitation reinforcement of TiC two-phase particles. 2. The rolling process adopts TMCP thermomechanical rolling, and obtains austenite grains with proper size by controlling parameters such as deformation temperature, deformation amount, deformation rate and the like, thereby improving the comprehensive mechanical property of the steel. 3. The invention can ensure the performance of the steel products and is more economic in component design system and production process, creates 500 yuan/ton steel for enterprises, reduces the consumption of customer steel products, improves the effective load of vehicles and reduces the weight of the whole vehicle and fuel consumption.
Drawings
FIG. 1 is a microscopic structure diagram of 1/4 locations of the thickness of 800L steel coil of high-strength beam steel in example 1;
FIG. 2 is a microscopic structure diagram of 1/2 locations of the thickness of 800L steel coil of the high-strength beam steel in example 1;
FIG. 3 is a microscopic structure diagram of 1/4 locations of the thickness of 800L steel coil of the high-strength beam steel in example 2;
FIG. 4 is a microscopic structure diagram of 1/2 locations of the thickness of 800L steel coil of the high-strength beam steel in example 2;
FIG. 5 is a microscopic structure diagram of 1/4 locations of the thickness of 800L steel coil of the high-strength beam steel in example 3;
FIG. 6 is a microscopic structure diagram of 1/2 locations of the thickness of 800L steel coil of the high-strength beam steel in example 3;
FIG. 7 is a microscopic structure diagram of 1/4 locations of the thickness of 800L steel coil of high-strength beam steel in example 4;
FIG. 8 is a microscopic structure diagram of 1/2 locations of the thickness of 800L steel coil of high-strength beam steel in example 4;
FIG. 9 is a microscopic structure diagram of 1/4 locations of the thickness of 800L steel coil of the high-strength beam steel in example 5;
fig. 10 is a microscopic structure diagram of 1/2 positions of the thickness of 800L steel coil of high-strength beam steel in example 5.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
Example 1
The high-strength beam steel with good low-temperature impact toughness of the embodiment has the thickness of 800L being 2.5mm, and comprises the following chemical components in percentage by mass: c: 0.07%, Si: 0.08%, Mn: 1.30%, P: 0.012%, S: 0.003%, Nb: 0.050%, Ti: 0.100%, Als: 0.30%, N: 0.0045 percent, and the balance of Fe and impurities within the allowable range.
The 800L production method of the high-strength beam steel with good low-temperature impact toughness comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling, and comprises the following specific process steps:
(1) a molten iron pretreatment process: pouring molten iron smelted by a blast furnace into a ladle, and putting the ladle into a desulfurization station for desulfurization treatment, wherein the molten iron S before desulfurization is as follows: 0.035%, adopting magnesium powder and lime for blowing and desulfurizing, controlling the ratio of the magnesium powder to the lime at 2.6, controlling the blowing time at 26min, controlling the magnesium powder blowing rate at 14kg/min, controlling the lime blowing rate at 37kg/min, and desulfurizing the desulfurized molten iron S in the desulfurizing station: 0.006%;
(2) smelting: adopting converter smelting, LF refining and RH refining processes;
in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 3.2, the oxygen blowing speed is controlled to be 11.2 m/s, and the total oxygen blowing time is controlled to be 950 s; in order to prevent the increase of N in molten steel, 280 Nm/h argon bottom blowing is carried out in the converter in the whole blowing process; air is prevented from being sucked, and the micro positive pressure of 15Pa at the converter mouth is ensured in the blowing process; the converter end point blowing temperature is 1640 ℃, and the end point C is controlled: 0.025%, P: 0.010%, O: 600 ppm; during tapping, a sliding plate is adopted for slag blocking, the slag discharging amount is strictly controlled, the tapping time is 5.5min, 12kg/t steel of electrolytic manganese alloy is added during tapping 1/4, lime is added during tapping 1/2, and the adding amount of the lime is 0.5kg/t steel;
an LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the steel is placed in a station to rapidly make white slag, the aluminum content in the station is controlled to be 320ppm, the steel is sampled and tested for components after the steel is formed into slag, and the alloy content of the molten steel is adjusted according to the components; controlling the heating time of LF power transmission molten steel to be 17min, controlling the heating speed to be 5.5 ℃/min, controlling the refining outlet temperature to be 1620 ℃, controlling the LF refining time to be 40min, not performing Ca treatment after refining, and blowing Ar gas for 6 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas quantity is 2200NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the circulation vacuum degree is 0.6mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 22min, and the pure degassing time is 6 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to a low position, and controlling the flow at 300 NL/min; performing Ca treatment when reaching a wire feeding position, controlling the Ca content of the molten steel at 22ppm, and performing soft blowing for 8min after the Ca treatment is finished;
(3) and (3) continuous casting process: the continuous casting process adopts dynamic soft reduction, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm; continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled to be 1.0m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow in each casting time to test the internal quality condition of a casting blank, the continuous casting pouring time is 38min, the slab ends are cut to be 2.5m, and the tail blanks are cut to be 2 m; the weight of the tundish molten steel is 55t, and the amount of the tundish residual steel is 20 t;
(4) a casting blank heating procedure: the temperature of the heating section is 1250 ℃, and the total heating time is 210 min;
(5) and (3) controlling a rolling process: the rolling is controlled in two stages, the first stage is rough rolling, 3+5 passes of rolling are adopted, the finish rolling temperature of the rough rolling is 1050 ℃, and the thickness of an intermediate blank at the outlet of the rough rolling is 46 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled at 1000 ℃, 7-pass rolling is carried out by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the last pass reduction rate is 21%, the cumulative reduction rate of the second stage is 93%, the finish rolling temperature of the finish rolling is controlled at 910 ℃, and the coiling temperature is 600 ℃;
(6) laminar cooling: and in the cold stage, 3/4 cooling mode is adopted, the cooling water temperature is controlled at 27 ℃, the cooling speed is controlled at 40 ℃/s, and the water consumption of each roll is 4200m for carrying out the high-speed thin film strip production.
The present embodiment has good low-temperature impact toughness and high strength beam steel 800L mechanical properties: the yield strength is 757MPa, the tensile strength is 817MPa, the elongation is 18.5 percent, the yield ratio is 0.93, the impact energy is 160J, 164J and 157J at the temperature of minus 20 ℃, and the bending test is qualified; the microstructure of the 1/4 position of the steel coil is shown in figure 1, the microstructure of the 1/2 position of the steel coil is shown in figure 2, and the microstructure is quasi-polygonal ferrite, acicular ferrite and TiC precipitate, wherein the grain size is 12.0 grade as shown in figures 1 and 2.
Example 2
The high-strength beam steel with good low-temperature impact toughness of the embodiment has the thickness of 800L being 6mm, and comprises the following chemical components in percentage by mass: c: 0.075%, Si: 0.10%, Mn: 1.40%, P: 0.010%, S: 0.002%, Nb: 0.055%, Ti: 0.110%, Als: 0.035%, N: 0.0048 percent, and the balance of Fe and impurities within the allowable range.
The 800L production method of the high-strength beam steel with good low-temperature impact toughness comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling, and comprises the following specific process steps:
(1) a molten iron pretreatment process: pouring molten iron smelted by a blast furnace into a ladle, and putting the ladle into a desulfurization station for desulfurization treatment, wherein the molten iron S before desulfurization is as follows: 0.040%, adopting magnesium powder and lime for blowing and desulfurizing, controlling the ratio of the magnesium powder to the lime to be 2.7, controlling the blowing time to be 27min, controlling the magnesium powder blowing rate to be 14.2kg/min, controlling the lime blowing rate to be 39kg/min, and desulfurizing the desulfurized molten iron S: 0.005 percent;
(2) smelting: adopting converter smelting, LF refining and RH refining processes;
in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 3.5, the oxygen blowing speed is controlled to be 11.5 m/s, and the total oxygen blowing time is controlled to be 1000 s; in order to prevent the increase of N in molten steel, 280 Nm/h argon bottom blowing is carried out in the converter in the whole blowing process; air is prevented from being sucked, and the micro positive pressure of 15Pa at the converter mouth is ensured in the blowing process; the converter end point blow-off temperature is 1650 ℃, and the end point C is controlled: 0.03%, P: 0.011%, O: 700 ppm; during tapping, a sliding plate is adopted for slag blocking, the slag discharging amount is strictly controlled, the tapping time is 6.2min, 12.1kg/t steel of electrolytic manganese is added during tapping 1/4, lime is added during tapping 1/2, and the adding amount of the lime is 0.7kg/t steel;
an LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the steel is placed in a station to rapidly make white slag, the aluminum content in the station is controlled to be 350ppm, the steel is sampled and tested for components after the steel is formed into slag, and the alloy content of the molten steel is adjusted according to the components; controlling the heating time of LF power transmission molten steel to be 17min, controlling the heating speed to be 5.3 ℃/min, controlling the refining outlet temperature to be 1625 ℃, controlling the LF refining time to be 45min, not performing Ca treatment after refining is finished, and blowing Ar gas for 6 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas flow is 2400NL/min, and a whole deep vacuum mode is adopted in the refining process; the circulation vacuum degree is 0.8mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 23min, and the pure degassing time is 6 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to a low position, and controlling the flow at 500 NL/min; performing Ca treatment when reaching a wire feeding position, controlling the Ca content of the molten steel at 25ppm, and performing soft blowing for 8min after the Ca treatment is finished;
(3) and (3) continuous casting process: the continuous casting process adopts dynamic soft reduction, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm; continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled to be 1.1m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow in each casting time to test the internal quality condition of a casting blank, the continuous casting pouring time is 40min, the slab ends are cut to be 2.5m, and the tail blanks are cut to be 2 m; the weight of the tundish molten steel is 50t, and the amount of the tundish residual steel is 18 t;
(4) a casting blank heating procedure: the temperature of the heating section is 1250 ℃, and the total heating time is 210 min;
(5) and (3) controlling a rolling process: the rolling is controlled in two stages, the first stage is rough rolling, 3+5 passes of rolling are adopted, the finish rolling temperature of the rough rolling is 1050 ℃, and the thickness of an intermediate blank at the outlet of the rough rolling is 46 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled at 1050 ℃, 7-pass rolling is carried out by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the final pass reduction rate is 22%, the cumulative reduction rate of the second stage is 87%, the finish rolling temperature is controlled at 900 ℃, and the coiling temperature is 605 ℃;
(6) laminar cooling: and in the stage of laminar cooling, an 3/4 cooling mode is adopted, the cooling water temperature is controlled at 29 ℃, the cooling speed is controlled at 32 ℃/s, and the water consumption of each roll is 4400m for carrying out high-speed thin film tube rolling.
The present embodiment has good low-temperature impact toughness and high strength beam steel 800L mechanical properties: the yield strength is 767MPa, the tensile strength is 836MPa, the elongation is 17 percent, the yield ratio is 0.92, the impact energy is 150J, 154J and 157J at the temperature of minus 20 ℃, and the bending test is qualified; the microstructure of the steel coil with the thickness of 1/4 is shown in figure 3, the microstructure of the steel coil with the thickness of 1/2 is shown in figure 4, and the microstructure is quasi-polygonal ferrite, acicular ferrite and TiC precipitate, wherein the grain size is 12.5 grade according to figures 3 and 4.
Example 3
The high-strength beam steel with good low-temperature impact toughness of the embodiment has the thickness of 800L being 8mm, and comprises the following chemical components in percentage by mass: c: 0.070%, Si: 0.10%, Mn: 1.50%, P: 0.012%, S: 0.002%, Nb: 0.048%, Ti: 0.120%, Als: 0.035%, N: 0.0048 percent, and the balance of Fe and impurities within the allowable range.
The 800L production method of the high-strength beam steel with good low-temperature impact toughness comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling, and comprises the following specific process steps:
(1) a molten iron pretreatment process: pouring molten iron smelted by a blast furnace into a ladle, and putting the ladle into a desulfurization station for desulfurization treatment, wherein the molten iron S before desulfurization is as follows: 0.045%, adopting magnesium powder and lime for blowing and desulfurizing, controlling the proportion of the magnesium powder and the lime at 2.8, controlling the blowing time at 28min, controlling the magnesium powder blowing rate at 14.7kg/min, controlling the lime blowing rate at 39kg/min, and desulfurizing the desulfurized molten iron S in the desulfurizing station: 0.006%;
(2) smelting: adopting converter smelting, LF refining and RH refining processes;
in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 4.2, the oxygen blowing speed is controlled to be 11.7 m/s, and the total oxygen blowing time is controlled to be 1050 s; in order to prevent the increase of N in molten steel, 280 Nm/h argon bottom blowing is carried out in the converter in the whole blowing process; air is prevented from being sucked, and the micro positive pressure of 18Pa at the converter mouth of the converter is ensured in the blowing process; the converter end point blow-off temperature is 1650 ℃, and the end point C is controlled: 0.035%, P: 0.009%, O: 800 ppm; during tapping, a sliding plate is adopted for slag blocking, the slag discharging amount is strictly controlled, the tapping time is 5.5min, 12.2kg/t steel of electrolytic manganese is added during tapping 1/4, lime is added during tapping 1/2, and the adding amount of the lime is 0.6kg/t steel;
an LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the steel is placed in a station to rapidly make white slag, the aluminum content of the steel placed in the station is controlled to be 370ppm, the steel is sampled and tested for components after the steel is formed into slag, and the alloy content of the molten steel is adjusted according to the components; heating time of LF power transmission molten steel is controlled to be 18min, temperature rising speed is 5.8 ℃/min, refining outlet temperature is controlled to be 1630 ℃, LF refining time is 50min, Ca treatment is not carried out after refining is finished, and Ar gas blowing time is 6 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas flow is 2800NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the circulation vacuum degree is 0.7mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 23min, and the pure degassing time is 6 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to a low position, and controlling the flow at 600 NL/min; performing Ca treatment when reaching a wire feeding position, controlling the Ca content of the molten steel at 28ppm, and performing soft blowing for 8min after the Ca treatment is finished;
(3) and (3) continuous casting process: the continuous casting process adopts dynamic soft reduction, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm; continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled at 1.2m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow for each casting time to test the internal quality condition of a casting blank, the continuous casting pouring time is 38min, the slab ends are cut by 2.5m, and the tail blank is cut by 2 m; the weight of the tundish molten steel is 40t, and the amount of the tundish residual steel is 19 t;
(4) a casting blank heating procedure: the temperature of the heating section is 1250 ℃, and the total heating time is 210 min;
(5) and (3) controlling a rolling process: the rolling is controlled in two stages, the first stage is rough rolling, 3+5 passes of rolling are adopted, the finish rolling temperature of the rough rolling is 1050 ℃, and the thickness of an intermediate blank at the outlet of the rough rolling is 46 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled at 1000 ℃, 7-pass rolling is carried out by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the final pass reduction rate is 20%, the cumulative reduction rate of the second stage is 82%, the finish rolling temperature is controlled at 910 ℃, and the coiling temperature is 615 ℃;
(6) laminar cooling: and in the stage of cold stratification, an 3/4 cooling mode is adopted, the cooling water temperature is controlled at 29.5 ℃, the cooling speed is controlled at 30 ℃/s, and the water consumption of each roll is 4800 m.
The present embodiment has good low-temperature impact toughness and high strength beam steel 800L mechanical properties: the yield strength is 783MPa, the tensile strength is 845MPa, the elongation is 16 percent, the yield ratio is 0.93, the impact energy is 178J, 180J and 175J at the temperature of minus 20 ℃, and the bending test is qualified; the microstructure of the 1/4 position of the steel coil is shown in figure 5, the microstructure of the 1/2 position of the steel coil is shown in figure 6, and the microstructure is quasi-polygonal ferrite, acicular ferrite and TiC precipitate, and the grain size is 12.5 grade according to figures 5 and 6.
Example 4
The high-strength beam steel with good low-temperature impact toughness of the embodiment has the thickness of 800L being 2.0mm, and comprises the following chemical components in percentage by mass: c: 0.065%, Si: 0.15%, Mn: 1.60%, P: 0.014%, S: 0.003%, Nb: 0.045%, Ti: 0.120%, Als: 0.025%, N: 0.005%, and the balance of Fe and impurities within an allowable range.
The 800L production method of the high-strength beam steel with good low-temperature impact toughness comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling, and comprises the following specific process steps:
(1) a molten iron pretreatment process: pouring molten iron smelted by a blast furnace into a ladle, and putting the ladle into a desulfurization station for desulfurization treatment, wherein the molten iron S before desulfurization is as follows: 0.030%, adopting magnesium powder and lime for blowing and desulfurizing, controlling the ratio of the magnesium powder to the lime to be 2.5, controlling the blowing time to be 24min, controlling the magnesium powder blowing rate to be 13.5kg/min, controlling the lime blowing rate to be 36kg/min, and desulfurizing the desulfurized molten iron S in a desulfurizing station: 0.008 percent;
(2) smelting: adopting converter smelting, LF refining and RH refining processes;
in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 3.0, the oxygen blowing speed is controlled to be 11.0 m/s, and the total oxygen blowing time is controlled to be 900 s; in order to prevent the increase of N in molten steel, argon is blown from the bottom of the converter in 350 Nm/h in the whole blowing process; air is prevented from being sucked, and the micro positive pressure of 10Pa at the converter mouth of the converter is ensured in the blowing process; the end point blowing temperature of the converter is 1630 ℃, and the end point C is controlled: 0.040%, P: 0.015%, O: 500 ppm; during tapping, a sliding plate is adopted for slag blocking, the slag discharging amount is strictly controlled, the tapping time is 5.0min, 12.5kg/t steel of electrolytic manganese is added during tapping 1/4, lime is added during tapping 1/2, and the adding amount of the lime is 0.8kg/t steel;
an LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the steel is placed in a station to rapidly make white slag, the aluminum content of the steel is controlled to be 300ppm after the steel is placed in the station, the steel is sampled to assay components after the steel is formed into slag, and the alloy content of the molten steel is adjusted according to the components; controlling the heating time of LF power transmission molten steel to be 15min, controlling the temperature rise speed to be 5 ℃/min, controlling the refining outbound temperature to be 1640 ℃, controlling the LF refining time to be 35min, not performing Ca treatment after refining, and blowing Ar gas for 10 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas flow is 2000NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the circulation vacuum degree is 1.0mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 25min, and the pure degassing time is 10 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to a low position, and controlling the flow at 300 NL/min; performing Ca treatment when reaching a wire feeding position, controlling the Ca content of the molten steel at 20ppm, and performing soft blowing for 6min after the Ca treatment is finished;
(3) and (3) continuous casting process: the continuous casting process adopts dynamic soft reduction, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm; continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled at 0.9m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow for each casting time to test the internal quality condition of a casting blank, the continuous casting pouring time is 38min, the slab ends are cut to be 2.0m, and the tail blanks are cut to be 1.5 m; the weight of the tundish molten steel is 38t, and the amount of the tundish residual steel is 18 t;
(4) a casting blank heating procedure: the temperature of the heating section is 1270 ℃, and the total heating time is 200 min;
(5) and (3) controlling a rolling process: the rolling is controlled in two stages, the first stage is rough rolling, 3+5 passes of rolling are adopted, the finish rolling temperature of the rough rolling is 1060 ℃, and the thickness of a rough rolling outlet intermediate billet is 36 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled at 1000 ℃, 7-pass rolling is carried out by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the final pass reduction rate is 23%, the cumulative reduction rate of the second stage is 67%, the finish rolling temperature is controlled at 886 ℃, and the coiling temperature is 583 ℃;
(6) laminar cooling: and in the stage of cold stratification, an 3/4 cooling mode is adopted, the cooling water temperature is controlled at 25 ℃, the cooling speed is controlled at 50 ℃/s, and the water consumption of each roll is 5600 m.
The present embodiment has good low-temperature impact toughness and high strength beam steel 800L mechanical properties: the yield strength is 785MPa, the tensile strength is 818MPa, the elongation is 15%, the yield ratio is 0.96, the impact energy is 168J, 151J and 175J at the temperature of minus 20 ℃, and the bending test is qualified; the microstructure of the 1/4 position of the steel coil is shown in figure 7, the microstructure of the 1/2 position of the steel coil is shown in figure 8, and the microstructure is quasi-polygonal ferrite, acicular ferrite and TiC precipitate, wherein the grain size is 11.5 grade according to figures 7 and 8.
Example 5
The high-strength beam steel with good low-temperature impact toughness of the embodiment has the thickness of 800L being 16mm, and comprises the following chemical components in percentage by mass: c: 0.085%, Si: 0.05%, Mn: 1.35%, P: 0.012%, S: 0.002%, Nb: 0.065%, Ti: 0.105%, Als: 0.015%, N: 0.0045 percent, and the balance of Fe and impurities within the allowable range.
The 800L production method of the high-strength beam steel with good low-temperature impact toughness comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling, and comprises the following specific process steps:
(1) a molten iron pretreatment process: pouring molten iron smelted by a blast furnace into a ladle, and putting the ladle into a desulfurization station for desulfurization treatment, wherein the molten iron S before desulfurization is as follows: 0.050 percent, adopting magnesium powder and lime for blowing and desulfurizing, controlling the ratio of the magnesium powder to the lime at 3.0, controlling the blowing time at 30min, controlling the magnesium powder blowing rate at 15kg/min, controlling the lime blowing rate at 41kg/min, and desulfurizing the desulfurized molten iron S in a desulfurizing station: 0.006%;
(2) smelting: adopting converter smelting, LF refining and RH refining processes;
in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 4.5, the oxygen blowing speed is controlled to be 12.0 m/s, and the total oxygen blowing time is controlled to be 1100 s; in order to prevent the increase of N in the molten steel, argon is blown from the bottom of the converter in 200 Nm/h in the whole blowing process; air is prevented from being sucked, and the micro positive pressure of 20Pa at the converter mouth of the converter is ensured in the blowing process; the converter end point blowing-out temperature is 1660 ℃, and the control end point C is as follows: 0.020%, P: 0.010%, O: 900 ppm; during tapping, a sliding plate is adopted for slag blocking, the slag discharging amount is strictly controlled, the tapping time is 7min, 11.5kg/t steel of electrolytic manganese is added during tapping 1/4, lime is added during tapping 1/2, and the adding amount of the lime is 0.5kg/t steel;
an LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the steel is placed in a station to rapidly make white slag, the aluminum content in the station is controlled to be 400ppm, the steel is sampled and tested for components after the steel is formed into slag, and the alloy content of the molten steel is adjusted according to the components; controlling the heating time of LF power transmission molten steel to be 20min, the heating rate to be 6 ℃/min, the refining outbound temperature to be 1615 ℃, the LF refining time to be 55min, not performing Ca treatment after refining, and blowing Ar gas for 8 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas flow is 3000NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the circulation vacuum degree is 0.5mbar, alloy adjustment is started after vacuum treatment is carried out for 3.0min, the vacuum treatment time is 20min, and the pure degassing time is 8 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to a low position, and controlling the flow at 800 NL/min; performing Ca treatment when reaching a wire feeding position, controlling the Ca content of the molten steel at 30ppm, and performing soft blowing for 7min after the Ca treatment is finished;
(3) and (3) continuous casting process: the continuous casting process adopts dynamic soft reduction, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm; continuous casting adopts pipeline steel covering slag, the covering agent adopts an ultra-low carbon covering agent, the drawing speed is controlled to be 1.4m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow in each casting time to test the internal quality condition of a casting blank, the continuous casting pouring time is 45min, the slab end is cut to be 2.0m, and the tail blank is cut to be 1.8 m; the weight of the tundish molten steel is 65t, and the amount of the tundish residual steel is 25 t;
(4) a casting blank heating procedure: the heating section temperature is 1230 ℃, and the total heating time is 300 min;
(5) and (3) controlling a rolling process: the rolling is controlled in two stages, the first stage is rough rolling, 3+5 passes of rolling are adopted, the finish rolling temperature of the rough rolling is 1010 ℃, and the thickness of a rough rolling outlet intermediate billet is 50 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled at 1030 ℃, the finished product is rolled for 7 times by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the last secondary reduction rate is 20.5 percent, the accumulated reduction rate of the second stage is 80 percent, the finish rolling temperature of the finish rolling is controlled at 914 ℃, and the coiling temperature is 617 ℃;
(6) laminar cooling: and in the stage of laminar cooling, an 3/4 cooling mode is adopted, the cooling water temperature is controlled at 33 ℃, the cooling speed is controlled at 23 ℃/s, and the water consumption of each roll is 5000m for carrying out the high-speed thin film strip production.
The present embodiment has good low-temperature impact toughness and high strength beam steel 800L mechanical properties: the yield strength is 766MPa, the tensile strength is 836MPa, the elongation is 19 percent, the yield ratio is 0.92, the impact energy is 120J, 128J and 133J at the temperature of minus 20 ℃, and the bending test is qualified; the microstructure of the 1/4 position of the steel coil is shown in figure 9, the microstructure of the 1/2 position of the steel coil is shown in figure 10, and the microstructure is quasi-polygonal ferrite, acicular ferrite and TiC precipitate, wherein the grain size is 13.0 grade according to figures 9 and 10.
Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.
Claims (4)
1. The high-strength beam steel 800L with good low-temperature impact toughness is characterized in that the high-strength beam steel 800L comprises the following chemical components in percentage by mass: c: 0.065-0.085%, Si: 0.05-0.15%, Mn: 1.30-1.60%, P is less than or equal to 0.014%, S is less than or equal to 0.003%, Nb: 0.055-0.065%, Ti: 0.100-0.120%, Als: 0.015-0.035%, N is less than or equal to 0.005%, and the balance is Fe and impurities within an allowable range;
the 800L thickness specification of the high-strength beam steel is 2.0-16.0 mm, the metallographic structure is quasi-polygonal ferrite, acicular ferrite and TiC educt, and the grain size is 11.5-13.0 grade;
the high-strength beam steel has the mechanical properties of 800L: the yield strength is 720-790 MPa, the tensile strength is 810-900 MPa, and the impact energy of a full-size sample at-20 ℃ is 120-180J; the elongation is 15-19%, and the yield ratio is 0.92-0.96;
the high-strength beam steel 800L is produced by the following method: the method comprises the working procedures of molten iron pretreatment, smelting, continuous casting, casting blank heating, controlled rolling and laminar cooling; the smelting process adopts converter smelting, LF refining and RH refining processes; in the converter smelting process, the alkalinity of furnace slag in the converter is controlled to be 3.0-4.5, the oxygen blowing speed is controlled to be 11-12 m/s, and the total oxygen blowing time is controlled to be 900-1100 s; in order to prevent the increase of N in molten steel, argon is blown from the bottom of the converter in the whole blowing process for 200-350 Nm/h; air is prevented from being sucked, and the micro positive pressure of the converter mouth of the converter is ensured to be 10-20 Pa in the blowing process; the end point blowing temperature of the converter is 1630-1660 ℃, and the end point C is controlled: 0.02-0.04%, P is less than or equal to 0.015%, O: 500 to 900 ppm; the method comprises the following steps of (1) stopping slag by using a sliding plate during tapping, strictly controlling the slag discharging amount, wherein the tapping time is 5-7 min, adding 11.5-12.5 kg/t of steel of electrolytic manganese alloy during tapping 1/4, adding lime during tapping 1/2, and adding the lime at an amount of 0.5-0.8 kg/t of steel;
the LF refining process adopts a double refining process, aluminum particles, lime and fluorite are added after the materials enter a station to rapidly make white slag, the aluminum content of the materials entering the station is controlled to be 300-400 ppm, the materials are sampled and tested for components after the materials are formed into slag, and the alloy content of the molten steel is adjusted according to the components; heating time of LF power transmission molten steel is controlled to be 15-20 min, the temperature rising speed is 5-6 ℃/min, the refining outlet temperature is controlled to be 1615-1640 ℃, LF refining time is 35-55 min, Ca treatment is not carried out after refining is finished, and the net Ar gas blowing time is 6-10 min;
in the RH refining process, Ar gas is adopted as RH refining circulation gas, the circulation gas amount is 2000-3000 NL/min, and a whole-process deep vacuum mode is adopted in the refining process; the vacuum degree of the vacuum tank is less than or equal to 1.0mbar, alloy adjustment is started after vacuum treatment is carried out for 3min, the vacuum treatment time is 20-25 min, and the pure degassing time is 6-10 min; after the vacuum is finished, opening bottom blowing argon after the ladle is lowered to the ground, and controlling the flow at 300-800 NL/min; performing Ca treatment when the molten steel reaches a wire feeding position, controlling the Ca content of the molten steel to be 20-30 ppm, and after the Ca treatment is finished, performing soft blowing for 6-8 min;
in the continuous casting process, dynamic soft reduction is adopted, the reduction of the solidification tail end is increased, and the reduction is increased from 1.5mm to 2.0 mm;
in the rolling control procedure, two-stage rolling control is adopted, the first stage is rough rolling, 3+ 5-pass rolling is adopted, the finish rolling temperature of the rough rolling is 1010-1060 ℃, and the thickness of a rough rolling outlet intermediate blank is 36-50 mm; the second stage is finish rolling, the inlet temperature of the finish rolling is controlled to be 1000-1050 ℃, the steel is rolled for 7 times by an F1-F7 finishing mill group, the descaling water between finishing mill frames is fully opened, the last secondary reduction rate is 20-23%, the accumulated reduction rate of the second stage is 67-93%, the finish rolling temperature of the finish rolling is controlled to be 886-914 ℃, and the coiling temperature is 583-617 ℃;
in the laminar cooling process, a front-stage 3/4 cooling mode is adopted in a laminar cooling stage, namely a group of 4 water headers is adopted, 3 headers are arranged in each group, and water consumption of each roll is 4200-5600 m for carrying out the cultivation; the cooling water temperature is controlled to be 25-33 ℃, and the cooling speed is controlled to be 23-50 ℃/s.
2. The production method of 800L of the high-strength beam steel with good low-temperature impact toughness according to claim 1, which comprises the working procedures of molten iron pretreatment, smelting, continuous casting, billet heating, controlled rolling and laminar cooling; the molten iron pretreatment process comprises the following steps of pouring molten iron smelted in a blast furnace into a ladle, enabling the ladle to enter a desulfurization station for desulfurization treatment, and preparing molten iron S before desulfurization: 0.030-0.050%, adopting magnesium powder and lime for blowing and desulfurizing, wherein the molten iron S after desulfurization treatment in a desulfurization station is less than or equal to 0.008%; the ratio of the magnesium powder to the lime is controlled to be 2.5-3.0, the spraying time is controlled to be 24-30 min, the spraying rate of the magnesium powder is controlled to be 13.5-15.0 kg/min, and the spraying rate of the lime is controlled to be 36-41 kg/min.
3. The production method of 800L of strong beam steel with good low-temperature impact toughness and high strength according to claim 2, characterized in that in the continuous casting process, pipeline steel covering slag is adopted for continuous casting, an ultra-low carbon covering agent is used as the covering agent, the drawing speed is controlled to be 0.9-1.4 m/min, constant-drawing-speed casting is adopted, one sulfur sample is taken per flow for each casting time to check the internal quality condition of a casting blank, the continuous casting pouring time is 38-45 min, the slab head is cut by 2.0-2.5 m, and the tail blank is cut by 1.5-2.0 m; the weight of the tundish molten steel is 38-65 t, and the amount of the tundish residual steel is 18-25 t.
4. The production method of 800L of high-strength beam steel with good low-temperature impact toughness according to claim 2 or 3, wherein in the casting blank heating process, the temperature of a heating section is 1230-1270 ℃, and the total heating time is 200-300 min.
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| CN114438407B (en) * | 2021-12-29 | 2022-12-09 | 安徽工业大学 | High-fatigue-strength girder steel thick plate and preparation method thereof |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101565794A (en) * | 2008-04-22 | 2009-10-28 | 宝山钢铁股份有限公司 | High-strength hot rolling automotive frame steel plate and manufacturing method thereof |
| CN103757538A (en) * | 2013-12-28 | 2014-04-30 | 首钢总公司 | Wide-thick steel plate for high-Ti 700MPa-level engineering machine and production method |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN103757538A (en) * | 2013-12-28 | 2014-04-30 | 首钢总公司 | Wide-thick steel plate for high-Ti 700MPa-level engineering machine and production method |
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