CN110983190A - 645 MPa-level high-strength anti-seismic ribbed steel bar and production method thereof - Google Patents
645 MPa-level high-strength anti-seismic ribbed steel bar and production method thereof Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 99
- 239000010959 steel Substances 0.000 title claims abstract description 99
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 31
- 238000005096 rolling process Methods 0.000 claims abstract description 69
- 238000001816 cooling Methods 0.000 claims abstract description 68
- 238000005266 casting Methods 0.000 claims abstract description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 44
- 238000009749 continuous casting Methods 0.000 claims abstract description 27
- 238000000034 method Methods 0.000 claims abstract description 17
- 239000000126 substance Substances 0.000 claims abstract description 12
- 230000008569 process Effects 0.000 claims abstract description 11
- 239000012535 impurity Substances 0.000 claims abstract description 10
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 20
- 238000010438 heat treatment Methods 0.000 claims description 18
- 229910001562 pearlite Inorganic materials 0.000 claims description 13
- 238000007670 refining Methods 0.000 claims description 13
- 230000035515 penetration Effects 0.000 claims description 11
- 229910000859 α-Fe Inorganic materials 0.000 claims description 11
- 229910052786 argon Inorganic materials 0.000 claims description 10
- 238000003723 Smelting Methods 0.000 claims description 9
- 238000010079 rubber tapping Methods 0.000 claims description 9
- 238000002791 soaking Methods 0.000 claims description 8
- 239000002893 slag Substances 0.000 claims description 7
- 238000007664 blowing Methods 0.000 claims description 4
- 239000000498 cooling water Substances 0.000 claims description 2
- 238000009826 distribution Methods 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 230000001681 protective effect Effects 0.000 claims description 2
- 230000007547 defect Effects 0.000 abstract description 6
- 238000009628 steelmaking Methods 0.000 abstract description 4
- 238000010583 slow cooling Methods 0.000 abstract description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000005728 strengthening Methods 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
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- 239000006104 solid solution Substances 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000005554 pickling Methods 0.000 description 3
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
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- 229910052758 niobium Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 229910052720 vanadium Inorganic materials 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910000592 Ferroniobium Inorganic materials 0.000 description 1
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 1
- 229910000628 Ferrovanadium Inorganic materials 0.000 description 1
- 229910001199 N alloy Inorganic materials 0.000 description 1
- 229910000720 Silicomanganese Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- -1 and at the moment Inorganic materials 0.000 description 1
- SKKMWRVAJNPLFY-UHFFFAOYSA-N azanylidynevanadium Chemical compound [V]#N SKKMWRVAJNPLFY-UHFFFAOYSA-N 0.000 description 1
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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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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
- B21B1/163—Rolling or cold-forming of concrete reinforcement bars or wire ; Rolls therefor
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- 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
- C22C33/06—Making ferrous alloys by melting using master alloys
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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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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Abstract
The invention provides a 645 MPa-level high-strength anti-seismic ribbed steel bar and a production method thereof, wherein the 645 MPa-level high-strength anti-seismic ribbed steel bar comprises the following chemical components in percentage by weight: 0.25-0.28% of C, 0.65-0.80% of Si, 1.45-1.55% of Mn, 0.130-0.150% of V, 0.020-0.030% of Nb0.020%, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 0.0120-0.0135% of N, less than or equal to 0.58% of Ceq, and the balance of Fe and inevitable impurities; the invention solves the problems of surface defects of casting blanks and pit entering and slow cooling by controlling the continuous casting process, and improves the production efficiency between the steel-making and steel-rolling processes; the water cooling process of the two sections of water tanks before and after pre-finish rolling in the rolling process is reasonably controlled, so that the steel bar obtains good strength, toughness and anti-seismic performance.
Description
Technical Field
The invention belongs to the technical field of steel bar production, and particularly relates to a 645 MPa-grade high-strength anti-seismic ribbed steel bar and a production method thereof.
Background
The use of the high-strength steel bars is used as a new technology in the construction industry, and is listed as one of ten new technologies which are mainly popularized by the housing and urban and rural construction department in 2017. The state revises the standard of hot rolled ribbed steel bars in 2018, and increases the HRB600 grade, but the standard does not have anti-seismic steel bars above 600 MPa. The anti-seismic twisted steel bar with the strength of 630Mpa has a plurality of advantages in the application of constructional engineering, can solve the problem of fat beams and fat columns in a building structure, can increase the using area of a building, can also make the structural design more flexible, and improves the using function of the building. In addition, the high-strength anti-seismic material can improve the building quality, prolong the service life and reduce the maintenance and use cost. According to the measurement and calculation of an authority, the application of more than 630 MPa-grade high-strength steel bars to replace 400 MPa-grade common steel bars in beams and plates can save about 30-40% of steel,
however, in the actual production process, the domestic steel mills produce 600MPa or 630MPa hot-rolled anti-seismic reinforcing steel bars, the indexes such as the yield ratio, the elongation and the like are not easy to meet the requirements, and the casting blank can be rolled and rolled only after being put into a pit and slowly cooled for more than or equal to 24 hours, so that the production efficiency among the working procedures is seriously influenced, the process is complex, the cost is high, the energy consumption is high and the like, and the steel mills producing the hot-rolled anti-seismic threaded reinforcing steel bars with higher strength of more than 645MPa are almost zero.
Disclosure of Invention
In order to solve the technical problems, the invention provides a 645 MPa-grade high-strength anti-seismic ribbed steel bar and a production method thereof. The problems of surface defects of casting blanks and pit entering and slow cooling are solved by controlling a continuous casting and casting process, and the production efficiency between steel making and rolling processes is improved; the water cooling process of the two sections of water tanks before and after pre-finish rolling in the rolling process is reasonably controlled, so that the steel bar obtains good strength, toughness and anti-seismic performance.
The technical scheme adopted by the invention is as follows:
a645 MPa-grade high-strength anti-seismic ribbed steel bar comprises the following chemical components in percentage by weight: 0.25-0.28% of C, 0.65-0.80% of Si, 1.45-1.55% of Mn, 0.130-0.150% of V, 0.020-0.030% of Nb0.020%, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 0.0120-0.0135% of N, less than or equal to 0.58% of Ceq, and the balance of Fe and inevitable impurities.
Further, the 645MPa grade high-strength anti-seismic ribbed steel bar preferably comprises the following chemical components in percentage by weight: 0.26-0.27% of C, 0.70-0.73% of Si0.51-1.53% of Mn1.51, 0.138-0.144% of V, 0.022-0.024% of Nb0.020% or less of P, 0.012% or less of S, 0.0122-0.0130% of N, 0.54-0.57% of Ceq0.54, and the balance of Fe and inevitable impurities.
Wherein Ceq is C + Mn/6+ (Cr + V + Mo)/5+ (Cu + Ni)/15.
The 645 MPa-level high-strength anti-seismic ribbed steel bar has a microstructure of ferrite and fine pearlite, wherein the ferrite accounts for 40-44%, and the grain size grade is 9.5-11; the yield strength is 655-710 MPa, the tensile strength is more than or equal to 820MPa, the tensile strength/yield strength is more than or equal to 1.25, the elongation after fracture is more than or equal to 15%, and the total elongation under maximum force is more than or equal to 9%.
The invention also provides a production method of the 645 MPa-level high-strength anti-seismic ribbed steel bar, which comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
Further, in the smelting step of the converter, molten iron is mixed according to the mass ratio: scrap steel 120 ± 2: a stable loading system of 20 plus or minus 2; the requirement of the end point C of the converter is more than 0.08 percent; slag stopping and tapping, wherein when molten steel of 1/3 steel is tapped, in order to ensure the yield of the precious microalloy alloy, auxiliary materials and strong deoxidizers are added in the early stage to add the precious alloy, so that the alloy feeding sequence is as follows: carburant → silicomanganese → ferrosilicon → vanadium-nitrogen alloy or ferrovanadium → ferroniobium, and lime is added into the steel ladle at a ratio of 3.0-3.5 kg/t after tapping; the flow rate of argon blown from the bottom of the steel ladle is 120-200 NL/min, and the stirring time is 4-7 min, so that elements of the steel ladle are uniform before the steel ladle enters the LF furnace.
In the LF furnace refining step, in order to ensure the steel ladle slag surface to be crusted, the operation principle that the flow of large argon is adopted at the early stage, the flow in the middle stage of LF refining is reduced to melt slag and avoid molten steel oxidation is adopted, so that the flow of argon of 300-500 NL/min is blown through, the flow is reduced to 100-120L/min, slag melting is carried out for 10 minutes at the speed of 7-8, 2.0-2.5 kg/t of refining slag is added, chemical components are finely adjusted to a target range, then soft argon blowing operation is carried out, the soft blowing time is 5-10 minutes, and the flow of argon is suitable for ensuring that the molten steel surface is not exposed.
In the billet continuous casting step, molten steel is cast in a protective way in the whole process, and the water cooling of a casting blank adopts a weak cooling system, so that the temperature of the casting blank entering a straightening section is ensured to be more than 1000 ℃, and the generation of stress cracks of the casting blank caused by V or Nb, C and N precipitates is avoided; setting the cooling water flow of the crystallizer to be 120m3The secondary cooling specific water amount is 1.0L/kg, the distribution ratio of the four-section water of the secondary cooling section is 26:48:37:9, the pulling speed is improved, the uniform cooling of the casting blank is not facilitated, the production yield is limited by reducing the pulling speed, therefore, the pulling speed is preferably controlled to be 1.7-2.0 m/min, the uniform cooling of the casting blank is ensured by the weak cooling process and the proper pulling speed, and a 180mm square blank is obtained; the problems of surface defects of a casting blank and the fact that the casting blank can be rolled and rolled only after entering a pit and slowly cooling are solved by controlling parameters in a billet continuous casting process, and the production efficiency between steel making and rolling processes is improved;
in the step of hot delivery of the casting blank, the red hot casting blank is taken off line and then is directly delivered to steel rolling and then is fed into a heating furnace for steel charging and rolling through a delivery roller way, the feeding temperature of the casting blank is 550-650 ℃, and at the moment, austenite in the casting blank is completely converted into ferrite and pearlite.
The casting blank bar controlled rolling and controlled cooling step specifically comprises the steps of heating, rough rolling, intermediate rolling, water pre-penetration, finish rolling, water penetration and air cooling on a cooling bed.
Further, the heating process is to control the temperature of a soaking section to be 1100-1150 ℃; the tapping temperature is controlled to be 1030-1050 ℃.
According to the principle that the reduction of each section of a roughing mill, a medium rolling mill and a finishing mill is gradually reduced, the blank of the roughing mill and the medium rolling mill is thick and high in temperature, and is quickly rolled into a blank close to a finished product under large reduction as far as possible, so that the burden of the finishing mill is reduced by adopting the large reduction; in the finish rolling stage, the blank is rolled into various finished products with small deformation, so that a good surface and accurate dimensions are obtained. The reduction ratios of the screw threads of various specifications corresponding to rough rolling, medium rolling and finish rolling are shown in the following table 1:
TABLE 1
The sectional water-through cooling process of pre-water-through after the middle rolling and water-through after the finish rolling adopted in the steel rolling promotes the surface of the twisted steel to be at the temperature return in the whole operation process from the middle rolling to the water-through after the finish rolling, a fine grain layer is formed on the surface of the twisted steel, and the strength and the plasticity of the twisted steel are improved. If the temperature of the steel entering the finishing mill is too low, the instantaneous current overload of the finishing mill can cause the current overload phenomenon, and the maintenance of equipment is not facilitated. Therefore, the process controls the temperature before entering a finishing mill to be 900 +/-10 ℃ in consideration of tool equipment; after finish rolling, the steel bars are cooled in a light through water mode again and then are cooled in an air cooling mode on the cooling bed, the surface of the steel bars is bright blue and beautiful in color when the temperature of the cooling bed is too high, but the texture crystal grains are easy to be large and large, and the improvement of the performance of the threaded products is not facilitated; the temperature of the upper cooling bed is lower than 870 ℃, although the strength is improved, an abnormal structure is easy to form, the surface color of the steel bar is dark and does not meet the standard requirement, so the temperature of the upper cooling bed is set to be 880 +/-10 ℃.
In the components of the 645 MPa-level high-strength anti-seismic ribbed steel bar provided by the invention, the functions and the control of the components are as follows:
c plays a role in solid solution strengthening, can improve the pearlite content and the strength of steel, and can improve the yield ratio, but the welding performance is influenced and the plasticity is reduced due to the overhigh content, and the content of the C element is controlled to be 0.25-0.28%, preferably 0.26-0.27%.
Si plays a role in solid solution strengthening, can improve the strength of steel, has little influence on welding performance, but the toughness and plasticity of the steel are reduced due to the excessively high content of Si, and in the invention, the content of Si is controlled to be 0.65-0.80%, preferably 0.70-0.73%.
Mn also plays a role in solid solution strengthening, so that the strength of the steel is obviously improved, the hardenability of the steel is improved, the pearlite content is improved, and the yield ratio is improved.
V is a main strengthening element, the formed V (C, N) compound has a strong pinning effect on grain boundaries and dislocation, crystal grains can be refined, and the strength can be obviously improved, but V (C, N) is easy to separate out along the grain boundaries to form casting blank surface cracks which are not beneficial to rolling of steel rolling, and in the invention, the content of the V element is controlled to be 0.130-0.150%, preferably 0.138-0.144%.
The precipitation temperature of C, N compound of Nb element is above 1200 ℃, which has the function of hindering the movement of austenite grain boundary and can play the role of fine grain strengthening, but when the Nb content is too high, the generated Nb (C, N) precipitates along the grains and is easy to form stress cracks on the surface of a casting blank in the hot blank casting process, and simultaneously, the plasticity and the toughness of the steel can be reduced, and the content of V element is controlled to be 0.020-0.030%, preferably 0.022-0.024%.
P, S element is harmful element, which damages the plasticity of steel, the cost is increased greatly when the content is too low, in the invention, P, S mass fraction is less than or equal to 0.030%.
Compared with the prior art, the production method of the HRB645E high-strength anti-seismic twisted steel provided by the invention has the advantages that after steel-making control components are carried out, the surface quality of a casting blank is qualified under a continuous casting and weak cooling process, the casting blank can be directly hot-rolled, and the production efficiency is improved; the method is characterized in that V, Nb solid solution is more sufficient when the tapping temperature of a casting blank is 1030-1050 ℃ after the casting blank is heated, two sections of water are cooled in a grading manner before and after finish rolling in the rolling process, the precipitation strengthening effect is improved, more compact fine crystal layers are formed on the surface layer, and further the yield strength is improved.
The production method of the 645 MPa-level high-strength anti-seismic ribbed steel bar provided by the invention is simple to operate, low in production cost and high in operation efficiency, and the product has the characteristics of good strength and plasticity matching.
Drawings
FIG. 1 shows the results of example 1
The surface quality of the cross section of the HRB645E steel casting billet after low-time pickling is specified;
FIG. 2 shows a schematic view of a liquid crystal display device of example 1
500 metallographic structure of HRB645E steel;
FIG. 3 shows the results of example 2
The surface quality of the cross section of the HRB645E steel casting billet after low-time pickling is specified;
FIG. 4 shows the structure of example 2
200 x metallographic structure diagram of HRB645E steel specification;
FIG. 5 shows the structure of example 3
The surface quality of the HRB645E steel casting billet after low-time pickling is specified;
FIG. 6 shows the structure of example 3
Specification HRB645E steel 200 × metallographic structure.
Detailed Description
The present invention will be described in detail with reference to examples.
Example 1
A645 MPa-grade ribbed high-strength anti-seismic steel bar HRB645E comprises the following chemical components, by weight, 0.26% of C, 0.70% of Si, 1.51% of Mn, 0.138% of V, 0.022% of Nb0.020% or less of P, 0.012% or less of S, 0.0122% of N, 0.54% of Ceq0.54% of S, and the balance of Fe and inevitable impurities.
The production method of the 645 MPa-level ribbed high-strength anti-seismic steel bar HRB645E comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
In the step of billet continuous casting, the key lies in the control of continuous casting weak cooling and the water quantity of a continuous casting crystallizer is 120m3The secondary cooling specific water amount is 1.0L/Kg, the temperature of a straightening point of a withdrawal and straightening machine is 1012 ℃, the withdrawal speed is controlled to be 1.8m/min, and the surface of a casting blank is washed by low-power acid without cracks as shown in figure 1;
in the step of hot delivery of the casting blank, the temperature of hot charging of the blank is 605 ℃, the soaking temperature of heating is 1115-1130 ℃, and the temperature of discharging after heating is 1039 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
The method comprises the steps of measuring temperature of a deformed steel bar through water after rough and medium rolling, measuring temperature of 905 ℃ through water, then conducting weak water through water after finishing rolling, actually measuring temperature of 875-890 ℃ in a cooling bed, air-cooling the deformed steel bar on the cooling bed to form a ferrite and fine pearlite structure, wherein the ratio of ferrite to pearlite is 42% and the ratio of pearlite to 58%, and as shown in figure 2, actually measured data of mechanical properties are shown in a table 2.
Example 2
A645 MPa-grade ribbed high-strength anti-seismic steel bar HRB645E comprises the following chemical components in percentage by weight: 0.27% of C, 0.73% of Si, 1.52% of Mn1, 0.140% of V, 0.023% of Nb0, less than or equal to 0.017% of P, less than or equal to 0.009% of S, 0.0130% of N, 0.55% of Ceq0, and the balance of Fe and inevitable impurities.
The production method of the 645 MPa-level ribbed high-strength anti-seismic steel bar HRB645E comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
In the step of billet continuous casting, the key lies in the control of continuous casting weak cooling and the water quantity of a crystallizer is 120m3The secondary cooling specific water amount is 1.0L/Kg, the temperature of the straightening point of the withdrawal and straightening machine is 1020 ℃, the withdrawal speed is controlled to be 1.9m/min, and the surface of a casting blank is washed by low-power acid without cracks as shown in figure 3;
in the step of hot delivery of the casting blank, the hot charging temperature of the blank is 615 ℃, the soaking temperature of heating is 1120-1145 ℃, and the discharging temperature after heating is 1045 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
The method comprises the steps of measuring the temperature of the deformed steel bar by passing water after rough and medium rolling at 896 ℃, then passing water by passing the deformed steel bar through a finishing mill for rolling at 870-883 ℃ in a cold bed, performing air cooling and collecting to form a ferrite and fine pearlite structure, wherein the ferrite accounts for 41% and the pearlite accounts for 59%, and the measured data of mechanical properties are shown in a table 2 as shown in a figure 4.
Example 3
A645 MPa-grade ribbed high-strength anti-seismic steel bar HRB645E comprises the following chemical components in percentage by weight: 0.27% of C, 0.70% of Si0.70%, Mn1.53%, 0.144% of V, 0.024% of Nb0.024%, 0.012% of P, 0.008% of S, 0.0123% of N, 0.55% of Ceq0.55% and the balance of Fe and inevitable impurities.
The production method of the 645 MPa-level ribbed high-strength anti-seismic steel bar HRB645E comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
In the step of continuous casting of the square billet, the key points are that the continuous casting weak cooling is controlled, the water quantity of a crystallizer is 120m3/h, the secondary cooling specific water quantity is 1.0L/Kg, the temperature of a straightening point of a withdrawal and straightening machine is 1025 ℃, the withdrawal speed is controlled to be 1.85m/min, and the surface of a casting blank is washed by low-power acid without cracks as shown in figure 5;
in the step of hot delivery of the casting blank, the hot charging temperature of the blank is 610 ℃, the soaking temperature of heating is 1115-1135 ℃, and the tapping temperature after heating is 1047 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
The method comprises the steps of measuring temperature of threaded steel bars by passing water after rough and medium rolling at 900 ℃, then passing water by passing the threaded steel bars by a finishing mill for weak passing, actually measuring the temperature of the threaded steel bars in a cooling bed at 872-888 ℃, and performing air cooling collection to form a ferrite and pearlite structure, wherein the ferrite accounts for 43% and the pearlite accounts for 57%, as shown in figure 6, the actually measured data of mechanical properties are shown in table 2.
TABLE 2 tensile mechanical properties of HRB 645E-gauge rebar of examples 1-3
Comparative example 1
An anti-seismic ribbed steel bar comprises the following chemical components in percentage by weight: 0.24% of C, 0.71% of Si0.71%, Mn1.48%, 0.120% of V, 0.023% of Nb0.015% of P, 0.007% of S, 0.0120% of N, 0.51% of Ceq0.51% of N, and the balance of Fe and inevitable impurities.
The production method of the anti-seismic ribbed steel bar comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling;
in the step of billet continuous casting, the key lies in the control of continuous casting weak cooling and the water quantity of a crystallizer is 120m3The secondary cooling specific water amount is 1.0L/Kg, the temperature of a straightening point of a withdrawal and straightening machine is 1026 ℃, the withdrawal speed is controlled to be 1.9m/min, and the quality defect of a casting blank is avoided;
in the step of hot delivery of the casting blank, the hot charging temperature of the blank is 620 ℃, the soaking temperature of heating is 1110-1130 ℃, and the tapping temperature after heating is 1038 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
And (3) carrying out water penetration and temperature measurement on the deformed steel bar at 903 ℃ after rough and medium rolling, then carrying out weak water penetration after finish rolling, actually measuring the temperature of the deformed steel bar in a cooling bed at 875-885 ℃, carrying out air cooling and collecting to form a ferrite and pearlite structure, wherein the actually measured data of mechanical properties are shown in table 3.
Comparative example 2
An anti-seismic ribbed steel bar comprises the following chemical components in percentage by weight: 0.26% of C, 0.71% of Si0.71%, Mn1.54%, 0.140% of V, 0.021% of Nb0.018%, 0.012% of S, 0.0129% of N, 0.54% of Ceq0.54% of N, and the balance of Fe and inevitable impurities.
The production method of the anti-seismic ribbed steel bar comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling,
in the step of billet continuous casting, the key lies in the control of continuous casting weak cooling and the water quantity of a crystallizer is 120m3The secondary cooling specific water amount is 1.0L/Kg, the temperature of the straightening point of the withdrawal and straightening machine is 1026 ℃, and the withdrawal speed isThe casting blank quality defect is avoided by controlling the casting blank quality to be 1.9 m/min;
in the step of hot delivery of the casting blank, the hot charging temperature of the blank is 620 ℃, the soaking temperature of heating is 1110-1130 ℃, and the tapping temperature after heating is 1038 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
And (3) carrying out rough and medium rolling on the twisted steel, then carrying out water penetration and temperature measurement on the twisted steel, then carrying out rolling on the twisted steel by a finishing mill, then carrying out weak water penetration, carrying out actual measurement on the temperature of the twisted steel entering a cooling bed at 925-940 ℃, carrying out air cooling and collecting, wherein the actual measurement data of mechanical properties are shown in table 3.
Comparative example 3
An anti-seismic ribbed steel bar comprises the following chemical components in percentage by weight: 0.26% of C, 0.69% of Si, 1.51% of Mn1, 0.142% of V, 0.023% of Nb0, 0.019% of P, 0.013% of S, 0.0130% of N, 0.54% of Ceq0, and the balance of Fe and inevitable impurities.
The production method of the anti-seismic ribbed steel bar comprises the following steps: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
In the step of billet continuous casting, the key lies in the control of continuous casting weak cooling and the water quantity of a crystallizer is 120m3The secondary cooling specific water amount is 1.0L/Kg, the temperature of a straightening point of a withdrawal and straightening machine is 1026 ℃, the withdrawal speed is controlled to be 1.9m/min, and the quality defect of a casting blank is avoided;
in the step of hot delivery of the casting blank, the hot charging temperature of the blank is 620 ℃, the soaking temperature of heating is 1110-1130 ℃, and the tapping temperature after heating is 1038 ℃;
in the step of controlled rolling and controlled cooling of the bar, rolling
The temperature of the twisted steel is measured by forced penetration of water after rough and medium rolling at 850 ℃, then the twisted steel is forced penetration of water after rolling by a finishing mill, the temperature of the twisted steel is actually measured at 800-835 ℃, air cooling collection is carried out, the structure is not abnormal, but the elongation is poor, and the actually measured data of the mechanical property are shown in table 3.
TABLE 3 tensile mechanical Properties of HRB 645E-gauge twisted steel bars of comparative examples 1 to 3
The above detailed description of a 645MPa grade high strength anti-seismic ribbed bar and its method of manufacture with reference to the embodiments is illustrative and not restrictive, and several embodiments can be cited within the limits thereof, so that variations and modifications thereof without departing from the general concept of the present invention are intended to be within the scope of the present invention.
Claims (9)
1. A645 MPa-grade high-strength anti-seismic ribbed steel bar is characterized by comprising the following chemical components in percentage by weight: 0.25-0.28% of C, 0.65-0.80% of Si, 1.45-1.55% of Mn, 0.130-0.150% of V, 0.020-0.030% of Nb0.020%, less than or equal to 0.030% of P, less than or equal to 0.030% of S, 0.0120-0.0135% of N, less than or equal to 0.58% of Ceq, and the balance of Fe and inevitable impurities.
2. A645 MPa-grade high-strength anti-seismic ribbed steel bar according to claim 1, characterized in that the microstructure of the 645 MPa-grade high-strength anti-seismic ribbed steel bar is ferrite + fine pearlite structure, and the grain size grade is 9.5-11 grade; the yield strength is 655-710 MPa, the tensile strength is more than or equal to 820MPa, the tensile strength/yield strength is more than or equal to 1.25, the elongation after fracture is more than or equal to 15%, and the total elongation under maximum force is more than or equal to 9%.
3. A method for producing 645MPa grade high-strength earthquake-resistant ribbed steel bars, according to claim 1 or 2, comprising the steps of: converter smelting → LF furnace refining → square billet continuous casting → casting blank hot delivery → bar controlled rolling and controlled cooling.
4. The production method of claim 3, wherein in the LF furnace refining step, the argon is blown through at a rate of 300-500 NL/min, then the argon is reduced to 100-120L/min, slag melting is carried out for 10 minutes at a speed of 7-8, 2.0-2.5 kg/t of refining slag is added, chemical components are finely adjusted to a target range, then soft argon blowing is carried out, the soft argon blowing time is 5-10 minutes, and the argon flow is preferably that the molten steel surface is not exposed.
5. The production method according to claim 3, wherein in the billet continuous casting step, molten steel is cast in a protective way in the whole process, and the water cooling of the casting blank adopts a weak cooling system to ensure that the temperature of the casting blank entering a straightening section is more than 1000 ℃; setting the cooling water flow of the crystallizer to be 120m3And h, the specific water amount of secondary cooling is 1.0L/kg, the distribution ratio of the four-stage water of the secondary cooling stage is 26:48:37:9, and the drawing speed is controlled to be 1.7-2.0 m/min, so that a 180mm square billet is obtained.
6. The production method according to claim 3, wherein in the slab hot-conveying step, the hot-red slab is directly conveyed to a steel rolling and heating furnace for steel charging and rolling through a conveying roller way after being taken off line, and the temperature of the cast slab entering the furnace is 550-650 ℃.
7. The production method according to claim 3, wherein the controlled rolling and controlled cooling step of the cast blank bar specifically comprises the steps of heating, rough rolling, intermediate rolling, pre-water penetration, finish rolling, water penetration and air cooling on a cooling bed.
8. The production method according to claim 7, wherein the heating process is to control the temperature of a soaking section at 1100-1150 ℃; the tapping temperature is controlled to be 1030-1050 ℃.
9. The production method of claim 7, wherein the pre-through section before finish rolling is subjected to weak through-water cooling to ensure that the temperature before entering the finish rolling mill is controlled at 900 +/-10 ℃; after finish rolling, the steel bars are cooled by light water penetration cooling again and then are air-cooled on a cooling bed, and the temperature of the steel bars entering the cooling bed is 880 +/-10 ℃.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111945074A (en) * | 2020-08-28 | 2020-11-17 | 安徽吾兴新材料有限公司 | 635 MPa-grade high-strength anti-seismic reinforcing steel bar and preparation method thereof |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3012341A1 (en) * | 2013-06-19 | 2016-04-27 | Baoshan Iron & Steel Co., Ltd. | Zinc-induced-crack resistant steel plate and manufacturing method therefor |
| CN108342641A (en) * | 2018-01-11 | 2018-07-31 | 河钢股份有限公司承德分公司 | A kind of 630MPa grades of hot rolling high-strength quake-proof reinforcing steel bar and its production method |
| CN109161799A (en) * | 2018-09-20 | 2019-01-08 | 山东钢铁股份有限公司 | A kind of pillar of electrification rail contacting net is with hot rolled H-shaped and preparation method thereof |
| CN109881118A (en) * | 2019-04-17 | 2019-06-14 | 魏滔锴 | A kind of 650MPa grades of high-strength explosion-proof fire resisting reinforcing bar steel and its thermal mechanical rolling technique |
| CN110541108A (en) * | 2019-07-26 | 2019-12-06 | 马鞍山钢铁股份有限公司 | nb and V composite 700MPa grade high-strength anti-seismic steel bar steel and production method thereof |
-
2019
- 2019-12-26 CN CN201911407523.7A patent/CN110983190A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3012341A1 (en) * | 2013-06-19 | 2016-04-27 | Baoshan Iron & Steel Co., Ltd. | Zinc-induced-crack resistant steel plate and manufacturing method therefor |
| CN108342641A (en) * | 2018-01-11 | 2018-07-31 | 河钢股份有限公司承德分公司 | A kind of 630MPa grades of hot rolling high-strength quake-proof reinforcing steel bar and its production method |
| CN109161799A (en) * | 2018-09-20 | 2019-01-08 | 山东钢铁股份有限公司 | A kind of pillar of electrification rail contacting net is with hot rolled H-shaped and preparation method thereof |
| CN109881118A (en) * | 2019-04-17 | 2019-06-14 | 魏滔锴 | A kind of 650MPa grades of high-strength explosion-proof fire resisting reinforcing bar steel and its thermal mechanical rolling technique |
| CN110541108A (en) * | 2019-07-26 | 2019-12-06 | 马鞍山钢铁股份有限公司 | nb and V composite 700MPa grade high-strength anti-seismic steel bar steel and production method thereof |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| CN112210714A (en) * | 2020-09-01 | 2021-01-12 | 陕钢集团产业创新研究院有限公司 | High-strength anti-seismic reinforcing steel bar with yield strength of more than 650MPa and production method thereof |
| CN114836686B (en) * | 2021-06-10 | 2022-09-13 | 广西柳钢华创科技研发有限公司 | HRB600E normal speed hot rolled ribbed steel bar with strength-to-yield ratio more than 1.26 |
| CN113528938A (en) * | 2021-06-10 | 2021-10-22 | 广西柳钢华创科技研发有限公司 | HRB600E normal speed hot rolled ribbed steel bar with yield ratio more than 1.26 and production method thereof |
| CN113528938B (en) * | 2021-06-10 | 2022-04-29 | 广西柳钢华创科技研发有限公司 | HRB600E normal speed hot rolled ribbed steel bar with yield ratio more than 1.26 and production method thereof |
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