CN111575587A - Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying - Google Patents
Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying Download PDFInfo
- Publication number
- CN111575587A CN111575587A CN202010495496.XA CN202010495496A CN111575587A CN 111575587 A CN111575587 A CN 111575587A CN 202010495496 A CN202010495496 A CN 202010495496A CN 111575587 A CN111575587 A CN 111575587A
- Authority
- CN
- China
- Prior art keywords
- steel
- equal
- vanadium
- hrb600
- chromium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- 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
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
-
- 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- 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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/072—Treatment with gases
-
- 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
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
-
- 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
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/08—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires for concrete reinforcement
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses a method for producing HRB600 high-strength hot-rolled ribbed steel bars by vanadium-chromium microalloying, which comprises the following steps: the method comprises the following steps of converter smelting, LF refining, continuous casting, heating, rolling, cold bed air cooling and shearing, wherein in the converter smelting process, ferrosilicon, ferromanganese, silicomanganese alloy, ferrochromium and silicon-nitrogen alloy are added for silicon, manganese and chromium alloying when steel is tapped at 2/3, and in the LF refining process, ferrovanadium is added according to the component requirement when the temperature of molten steel in a refining furnace is more than or equal to 1570 ℃ for vanadium alloying. The invention has the advantages that: (1) the blank of producing 600 MPa-grade steel bars by V-Cr composite micro-alloying is filled, V, Cr is used as a micro-alloy strengthening element, Nb and Ti with generally high prices are avoided, and the production cost is reduced; (2) 80% of V exists in a precipitated state after rolling, so that the strength of the HRB600 hot-rolled ribbed steel bar is obviously improved; (3) a certain amount of Cr element is added into steel, so that the strength of the HRB600 hot-rolled ribbed steel bar is obviously improved, and the steel has certain corrosion resistance.
Description
Technical Field
The invention relates to a method for producing hot-rolled ribbed steel bars, in particular to a method for producing HRB600 high-strength hot-rolled ribbed steel bars by vanadium-chromium microalloying, belonging to the technical field of metallurgy.
Background
11, 1/2018, a new standard (GB/T1499.2-2018) for hot-rolled ribbed steel bars is released and implemented, and 600 MPa-level steel bars are added in the new standard. The high-strength hot-rolled ribbed steel bar has the characteristics of high strength and excellent comprehensive performance. At present, the strength grade of hot-rolled ribbed steel bars is mainly 400MPa grade, a small amount of hot-rolled ribbed steel bars are 500MPa grade, and various domestic manufacturers develop 600MPa grade high-strength steel bars (namely HRB600 high-strength steel bars) through V-N microalloying. The HRB600 high-strength steel bar has many advantages in the application of building engineering, compared with the currently mainly used 400MPa and 500MPa steel bars, the steel consumption can be saved by 44.4 percent and 19.5 percent, and the application of the high-strength material solves the problem of fat beam and fat column in the building structure, thereby not only increasing the using area of the building, but also leading the structural design to be more flexible and simultaneously improving the using function of the building. In addition, the high-strength material can improve the building quality, prolong the service life and reduce the maintenance and use cost. Meanwhile, under the background of the national strong advocation of energy conservation, emission reduction and environmental protection, as the construction industry of resource-consuming households, the condition that the common strength steel bar is used as a main steel material for buildings cannot meet the requirement of construction and development, and the development of the high-strength steel bar is a necessary trend of the development of a reinforced concrete structure in the field of construction engineering in the future. High-strength steel bars (such as korean standard SD600) have been popularized abroad, and in domestic, some projects have also started to use high-strength steel bars, which are hot-rolled ribbed steel bar products to be vigorously popularized.
The deformed steel bar is a high-strength steel bar, and is produced by mainly using elements such as Nb, V, Ti and the like as microalloy strengthening elements, and the production cost is relatively high due to the generally higher price of the alloys such as Nb, V, Ti and the like.
Disclosure of Invention
In order to solve the defects of the prior art, the invention aims to provide a method for producing HRB600 high-strength hot-rolled ribbed steel bars by vanadium-chromium microalloying, which fills the blank of producing 600 MPa-level steel bars by V-Cr composite microalloying, can reduce the production cost of high-strength steel bars, and can ensure that all performance indexes of the produced 600 MPa-level steel bars can fully meet the requirements of GB/T1499.2-2018.
In order to achieve the above object, the present invention adopts the following technical solutions:
the method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying is characterized in that the HRB600 high-strength hot-rolled ribbed steel bar produced by the method comprises the following chemical components in percentage by weight: c: 0.24% -0.28%, Si: 0.60-0.70%, Mn: 1.45% -1.55%, V: 0.12 to 0.18 percent of Cr, 0.30 to 0.40 percent of Cr, less than or equal to 0.035 percent of P, less than or equal to 0.020 percent of S, N: 0.012-0.018%, Ceq: less than or equal to 0.56 percent, and the balance of Fe and residual elements, and the method specifically comprises the following steps:
step 1: smelting in a converter
Preparing 75-85% of molten iron and 15-25% of scrap steel, controlling the weight percentage content of end-point components to be more than or equal to 0.08% of C and less than or equal to 0.030% of P, controlling the end-point temperature to be 1620-1650 ℃, adding silicon-calcium-aluminum powder and silicon-aluminum-barium balls for diffusion deoxidation when steel flows occur, adding Al ingots and composite deoxidizers for molten steel pre-deoxidation when steel is discharged at 1/3, adding ferrosilicon, ferromanganese, silicomanganese alloy, ferrochromium and silicon-nitrogen alloy for silicon, manganese and chromium alloying when steel is discharged at 2/3, and adding CaO for refining slag in large bags after the alloys are added;
step 2: LF refining
When the temperature of the molten steel in the refining furnace is more than or equal to 1570 ℃, adding ferrovanadium according to the component requirement for vanadium alloying, simultaneously blowing nitrogen, and when the nitrogen flow reaches 400 NL/min-600 NL/min, controlling the nitrogen increasing amount of the molten steel to be 8 ppm/min-15 ppm/min;
and step 3: continuous casting
Continuous casting and whole-process protective casting are adopted, the temperature of a tundish is controlled at 1530-1550 ℃, the drawing speed is 2.00-2.50 m/min, and the secondary cooling specific water amount is 0.8-1.5L/kg steel;
and 4, step 4: heating of
The temperature of the heating section is 1150 +/-30 ℃;
and 5: rolling of
The initial rolling temperature is 950-1050 ℃, the final rolling temperature is 900-1000 ℃, and water is not penetrated in the rolling process;
step 6: cold bed air cooling
Air cooling by adopting an air cooler;
and 7: shearing
And the arc shears are adopted for shearing, so that the end face of the steel is straight and tidy.
The method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying is characterized in that in the step 1, the composite deoxidizer contains 30-40% of Ca, 15-20% of C, 10-15% of Si and 5-10% of Al.
The method for producing the HRB600 high-strength hot-rolled ribbed steel bar through vanadium-chromium microalloying is characterized in that in the step 2, the soft argon blowing time is guaranteed to be more than or equal to 10min after refining is finished, and the temperature of a continuous casting platform on a refining ladle is 1560-1620 ℃.
The method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying is characterized in that in the step 6, the temperature of a lower cooling bed is less than or equal to 350 ℃.
The method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying is characterized in that in the step 7, the shearing temperature is less than or equal to 350 ℃.
The invention has the advantages that:
(1) the invention fills the blank of producing the 600 MPa-grade steel bar by V-Cr composite micro-alloying, takes V, Cr as a micro-alloy strengthening element, avoids using Nb and Ti with generally higher price, and reduces the production cost of the high-strength steel bar;
(2) according to the invention, through stably controlling the process parameters given in the working procedures of converter smelting, LF refining, continuous casting, heating and rolling, the fluctuation range of chemical elements in the produced steel is small and stable, the oxygen content is less than or equal to 30ppm, the inclusion level is low, the purity of molten steel is high, the mechanical property of the produced steel is stable, the yield strength is 630-680 MPa, the tensile strength is 760-890 MPa, the elongation A after fracture is more than or equal to 15%, the maximum elongation Agt is more than or equal to 10%, and all performance indexes can completely meet the requirements of GB/T1499.2-2018;
(3) the invention adopts the online combined nitrogen blowing and microalloying control technology, so that the nitrogen content in the steel is stabilized at 80-120 ppm, the recovery rate of ferrovanadium is more than 98 percent, and the V, N precipitation strengthening effect in the steel is promoted;
(4) according to the invention, the content of N in molten steel is balanced for the first time by adding aluminum ingots in the tapping process of the converter and adding silicon-nitrogen alloy after deoxidation by using a composite deoxidizer, then nitrogen is blown in according to the smelting temperature in the LF refining process, so that the content of N in the molten steel is stable, vanadium alloying is carried out by adding ferrovanadium into the LF refining furnace, and the vanadium recovery rate is high, so that the cost is low, the components are stable, the V, N content in steel is stably controlled from the two aspects, and the solidification process of the molten steel promotes the formation and precipitation of V, C, N fine particles, so that the utilization rate of V in the steel is improved;
(5) according to the invention, a high-temperature solid solution and hot rolling temperature control water-free rolling technology is adopted, V in steel is fully solid-dissolved by high-temperature heating, 80% of V exists in a precipitated state after rolling, the proportion of particles with the size less than 15nm in the precipitated particles is up to more than 50%, the section tissues are P + F, pearlite accounts for about 50% -60%, the grain size is up to more than 10 levels, and the strength of the HRB600 hot-rolled ribbed steel bar is obviously improved;
(6) according to the invention, a certain amount of Cr element is added into steel, the Cr atom can replace Fe atom, the replaced Fe atom is combined with C atom to form alloy cementite, the stability of pearlite is improved, the Cr atom can also be dissolved in ferrite, the strength and hardness of the ferrite are improved, and a solid solution strengthening effect is generated, so that the strength of the HRB600 hot-rolled ribbed steel bar is obviously improved, and the steel has a certain corrosion resistance;
(7) compared with 400MPa and 500 MPa-level anti-seismic steel bars, the HRB600 hot-rolled ribbed steel bar produced by the method provided by the invention has the practical significance of energy conservation, emission reduction, safety and environmental protection due to high strength and low cost.
Drawings
FIG. 1 is a graph of nitrogen increase rates at different temperatures;
FIGS. 2(A) and 2(B) are specification
A deformed steel bar structure picture of 100 times;
FIGS. 3(A) and 3(B) are specification
And (5) a 100-fold structural picture of deformed steel bar.
Detailed Description
The invention is described in detail below with reference to the figures and the embodiments.
One, the component requirement
In order to enable the yield strength of the HRB600 hot rolled ribbed steel bar obtained by production to reach 630-680 MPa, the tensile strength to reach 760-890 MPa, the elongation A after fracture to be more than or equal to 15%, the maximum elongation Agt to be more than or equal to 10%, and various performance indexes to fully meet the requirements of GB/T1499.2-2018, the main measures adopted are precipitation strengthening and fine grain strengthening of Cr and V microalloy elements, in order to ensure the precipitation amount of precipitates, the content of the V microalloy is adjusted to be about 0.140%, the content of nitrogen in steel is required to be within the range of 120-180 ppm, and the chemical components and the weight percentage content of each component of the HRB600 hot rolled ribbed steel bar are specifically required to be shown in a table 1.
TABLE 1 HRB600 Hot rolled ribbed bar chemical composition and weight percent of each component
Second, the production method
The method for producing the HRB600 hot-rolled ribbed steel bar specifically comprises the following steps: converter smelting, LF refining, continuous casting, heating, rolling, cold bed air cooling and shearing.
Step 1: smelting in a converter
A65 t converter was used for smelting.
The method comprises the steps of proportioning 75-85% of molten iron and 15-25% of scrap steel, wherein the content of Si in the molten iron is 0.20-0.80%, the content of P is less than or equal to 0.200%, the weight percentage content of end-point components is controlled to be more than or equal to 0.08%, the content of P is less than or equal to 0.030%, and the end-point temperature is 1620-1650 ℃. When steel flows, silicon-calcium-aluminum powder and silicon-aluminum-barium balls are added for diffusion deoxidation, when steel is discharged at 1/3, Al ingots and compound deoxidizers are added for molten steel deoxidation, and when steel is discharged at 2/3, ferrosilicon, ferromanganese, silicomanganese alloy, ferrochrome and silicon-nitrogen alloy are added for silicon, manganese and chromium alloying.
The ingredients are shown in Table 2.
TABLE 2 ingredients
| Steel grade | Molten iron% | Si in molten iron% | P in the molten iron% | Steel scrap% |
| HRB600-1 | 83.9 | 0.45 | 0.166 | 16.1 |
| HRB600-2 | 82.9 | 0.58 | 0.178 | 17.1 |
| HRB600-3 | 83.3 | 0.65 | 0.198 | 16.7 |
| HRB600-4 | 83.8 | 0.41 | 0.179 | 16.2 |
| HRB600-5 | 83.3 | 0.59 | 0.133 | 16.7 |
| HRB600-6 | 81.6 | 0.56 | 0.131 | 18.4 |
| HRB600-7 | 84.9 | 0.32 | 0.163 | 15.1 |
| HRB600-8 | 81.9 | 0.52 | 0.138 | 18.1 |
| HRB600-9 | 79.7 | 0.36 | 0.134 | 20.3 |
| HRB600-10 | 81.1 | 0.42 | 0.142 | 18.9 |
The end point composition and end point temperature are shown in Table 3.
TABLE 3 composition of end point and end point temperature
The adding sequence of the Al ingot, the composite deoxidizer and the alloy is as follows: 30kg of silicon-calcium-aluminum powder and 20kg of silicon-aluminum-barium balls are added for diffusion deoxidation during steel flow, 20kg of Al ingot and 30kg of composite deoxidizer (the composite deoxidizer contains 30-40% of Ca, 15-20% of C, 10-15% of Si and 5-10% of Al) are added for molten steel pre-deoxidation during steel tapping of 1/3, ferrosilicon, ferromanganese, silicomanganese, ferrochromium and silicon-nitrogen alloy are added for silicon, manganese and chromium alloying during steel tapping of 2/3, and 300kg +/-20 kg of CaO is added for ladle refining slag after the alloying is finished.
The double air bricks are ensured to be ventilated in the tapping process (so as to be beneficial to slag melting and alloy melting), nitrogen is used for stirring for 2-3min after tapping, and the diameter of a molten steel stirring turnover surface is 400-600 mm.
Step 2: LF refining
LF refining was performed using a 70t refining furnace.
According to the requirements of table 1, the compositions of the converter fed into the refining furnace were controlled as follows:
0.20-0.25% of C, 0.45-0.55% of Si, and the lower limit of Mn specification: +/-0.05% and P not more than 0.028%.
The total slag amount of the refining furnace is controlled to be 0.5-0.7 percent of the weight of the molten steel, a small amount of silicon carbide is used for adjusting the slag in the smelting process for many times, when the slag melting is good and the slag is white and the temperature T of the molten steel in the refining furnace is more than or equal to 1570 ℃, ferrovanadium is added according to the component requirement for vanadium alloying, a first sample is taken, the components are adjusted according to the internal control component requirement according to the analysis result of the first sample, nitrogen is blown in at the same time, when the nitrogen flow reaches 400 NL/min-600 NL/min, the nitrogen increasing amount of the molten steel is controlled to be 8 ppm/min-15 ppm/min, and the nitrogen content of the molten steel is ensured to be. The white slag holding time is more than or equal to 15min, the soft argon blowing time is more than or equal to 10min after refining, and the temperature of a continuous casting platform on a refining ladle is 1560-1620 ℃.
A large number of researches show that nitrogen is a very effective alloy element in vanadium-containing steel, and the yield strength of about 6MPa can be improved by adding 10ppm of nitrogen in the vanadium-containing steel. Therefore, we have studied the nitrogen blowing process of the refining furnace and obtained the nitrogen increasing rate graphs at different temperatures as shown in fig. 1, and it can be known from fig. 1 that, after the temperature of the molten steel is greater than 1570 ℃, the higher the nitrogen blowing temperature is, the larger the flow rate is, and the greater the nitrogen feeding rate is, and finally we have determined the following nitrogen blowing process of the molten steel according to the results of fig. 1:
when the temperature of the molten steel in the refining furnace is more than or equal to 1570 ℃, nitrogen is blown in, when the flow rate of the nitrogen reaches 400 NL/min-600 NL/min, the nitrogen increasing amount of the molten steel is controlled to be 8 ppm/min-15 ppm/min, and the nitrogen content of the molten steel is ensured to be within the range of 120 ppm-180 ppm.
And step 3: continuous casting
According to the requirements of table 1, continuous casting and full-process protection casting are adopted, aluminum-carbon long nozzles are adopted from a large ladle to a middle ladle, aluminum-carbon submerged nozzles are adopted from the middle ladle to a crystallizer, argon is introduced into the middle ladle before casting, and special covering slag for deformed steel bars is used. The baking temperature of the tundish is more than or equal to 980 ℃, and the pouring is started when the liquid level of the tundish is more than or equal to 700 mm. The submerged nozzle must be centered when pouring, and the insertion depth is 80 mm-110 mm. Stirring current of the crystallizer: 200 +/-5A. Frequency: 4 Hz. 1505 ℃, the target temperature of the tundish is controlled at 1530-1550 ℃, the pulling speed is 2.00-2.50 m/min, the target pulling speed is 2.25m/min, the water quantity of the crystallizer is as follows: 140t/h, and the secondary cooling specific water amount is 0.8L/kg steel to 1.5L/kg steel.
The continuous casting billet has clear mark and good surface, and has no serious defects of scabbing, cracks, slag channels and the like. The control of the continuous casting process is shown in Table 4.
TABLE 4 continuous casting Process control
And 4, step 4: heating of
And heating by adopting a heating furnace.
According to the requirements of table 1, in order to ensure the sufficient dissolution of the microalloy carbonitride and obtain more precipitates, the temperature of the preheating section of the heating furnace is 1050 +/-30 ℃, the temperature of the heating section is 1150 +/-30 ℃, the temperature of the soaking section is 1100 +/-30 ℃, and the total heating time is more than or equal to 180 min.
And 5: rolling of
And rolling by using an 18-frame continuous rolling unit.
According to the requirements of table 1, in order to ensure the sufficient dissolution of the microalloy carbonitride and obtain more precipitates, the initial rolling temperature of the continuous rolling mill set is 950-1050 ℃, the final rolling temperature is 900-1000 ℃, and water is not penetrated in the rolling process.
Step 6: cold bed air cooling
And (3) air cooling by using an air cooler, wherein the temperature of a lower cooling bed is less than or equal to 350 ℃.
And 7: shearing
The arc shears are adopted for shearing, the shearing temperature is less than or equal to 350 ℃, and the end faces of the steel products are ensured to be straight and tidy.
And finally, bundling and packaging the materials in a full size according to the standard or regulation requirements. The steel label is executed according to the relevant management regulations, and the label needs to indicate the grade, specification, furnace number, count and weight of each bundle.
Third, inspection
The steel produced by the method is subjected to chemical component and mechanical property inspection.
1. Chemical composition test
The chemical compositions of the steels produced by the above method were examined and the results are shown in table 5.
TABLE 5 chemical composition of steels
2. High power test
The steel products produced by the method are subjected to high-power inspection on non-metallic inclusions, textures and grain sizes, and the inspection results are shown in Table 6.
TABLE 6 examination and analysis of inclusions and microstructure
Wherein, the steel grade HRB600-6 and the specification
The picture of the 100-fold structure of the deformed steel bar is shown in figure 2(A), and the steel grade HRB600-3 and the specification
The picture of the structure of the deformed steel bar of (2) is shown in FIG. 2 (B).
The evaluation shows that the specification of the steel grade HRB600-1 to HRB600-10
The structure of the deformed steel bar is ferrite plus pearlite, the integral grain size is more than 10 grade, and the structure is relatively uniform on the whole.
HRB600-2, specification of steel grade
The picture of the 100-fold structure of the deformed steel bar is shown in figure 3(A), and the steel grade HRB600-7 and the specification
The picture of the structure of the deformed steel bar of 100 times is shown in FIG. 3 (B).
The evaluation shows that the specification of the steel grade HRB600-1 to HRB600-10
The structure of the deformed steel bar is ferrite plus pearlite, the grain size is more than 10.5 grade, and the structure is relatively uniform on the whole.
3. Mechanical property test
For the above specification
The deformed steel bars were subjected to mechanical property tests, and the test results are shown in Table 7.
TABLE 7 mechanical Properties of the steels
As can be seen from Table 7, the yield strength of the steel produced by the method provided by the invention reaches 630-660 MPa, the tensile strength reaches 790-830 MPa, the elongation A after fracture reaches more than 15%, the maximum elongation Agt reaches more than 10%, all performance indexes meet the requirements of the standard GB/T1499.2-2018, the curve is normal, an obvious yield platform is provided, and the plasticity index is good.
It should be noted that the above-mentioned embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the protection scope of the present invention.
Claims (5)
1. The method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying is characterized in that the HRB600 high-strength hot-rolled ribbed steel bar produced by the method comprises the following chemical components in percentage by weight: c: 0.24% -0.28%, Si: 0.60-0.70%, Mn: 1.45% -1.55%, V: 0.12 to 0.18 percent of Cr, 0.30 to 0.40 percent of Cr, less than or equal to 0.035 percent of P, less than or equal to 0.020 percent of S, N: 0.012-0.018%, Ceq: less than or equal to 0.56 percent, and the balance of Fe and residual elements, and the method specifically comprises the following steps:
step 1: smelting in a converter
Preparing 75-85% of molten iron and 15-25% of scrap steel, controlling the weight percentage content of end-point components to be more than or equal to 0.08% of C and less than or equal to 0.030% of P, controlling the end-point temperature to be 1620-1650 ℃, adding silicon-calcium-aluminum powder and silicon-aluminum-barium balls for diffusion deoxidation when steel flows occur, adding Al ingots and composite deoxidizers for molten steel pre-deoxidation when steel is discharged at 1/3, adding ferrosilicon, ferromanganese, silicomanganese alloy, ferrochromium and silicon-nitrogen alloy for silicon, manganese and chromium alloying when steel is discharged at 2/3, and adding CaO for refining slag in large bags after the alloys are added;
step 2: LF refining
When the temperature of the molten steel in the refining furnace is more than or equal to 1570 ℃, adding ferrovanadium according to the component requirement for vanadium alloying, simultaneously blowing nitrogen, and when the nitrogen flow reaches 400 NL/min-600 NL/min, controlling the nitrogen increasing amount of the molten steel to be 8 ppm/min-15 ppm/min;
and step 3: continuous casting
Continuous casting and whole-process protective casting are adopted, the temperature of a tundish is controlled at 1530-1550 ℃, the drawing speed is 2.00-2.50 m/min, and the secondary cooling specific water amount is 0.8-1.5L/kg steel;
and 4, step 4: heating of
The temperature of the heating section is 1150 +/-30 ℃;
and 5: rolling of
The initial rolling temperature is 950-1050 ℃, the final rolling temperature is 900-1000 ℃, and water is not penetrated in the rolling process;
step 6: cold bed air cooling
Air cooling by adopting an air cooler;
and 7: shearing
And the arc shears are adopted for shearing, so that the end face of the steel is straight and tidy.
2. The method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying according to claim 1, wherein in the step 1, the compound deoxidizer contains 30-40% of Ca, 15-20% of C, 10-15% of Si and 5-10% of Al.
3. The method for producing the HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying as claimed in claim 1, wherein in step 2, the soft argon blowing time is guaranteed to be more than or equal to 10min after refining is finished, and the temperature of a continuous casting platform on a refining ladle is 1560-1620 ℃.
4. The method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying as claimed in claim 1, characterized in that in step 6, the lower cooling bed temperature is less than or equal to 350 ℃.
5. The method for producing HRB600 high strength hot rolled ribbed steel bar by vanadium-chromium microalloying as claimed in claim 1, characterized in that in step 7, the shearing temperature is less than or equal to 350 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010495496.XA CN111575587A (en) | 2020-06-03 | 2020-06-03 | Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010495496.XA CN111575587A (en) | 2020-06-03 | 2020-06-03 | Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111575587A true CN111575587A (en) | 2020-08-25 |
Family
ID=72118152
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010495496.XA Pending CN111575587A (en) | 2020-06-03 | 2020-06-03 | Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111575587A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112375974A (en) * | 2020-10-28 | 2021-02-19 | 南京钢铁股份有限公司 | Deformed steel bar produced by high-chromium molten iron and preparation method thereof |
| CN112981259A (en) * | 2021-02-08 | 2021-06-18 | 青海西钢特殊钢科技开发有限公司 | HRB400E ribbed steel bar produced by substituting vanadium with chromium and method |
| CN113441545A (en) * | 2021-06-10 | 2021-09-28 | 广西柳钢华创科技研发有限公司 | HRB500E normal speed hot rolled ribbed steel bar with yield ratio more than 1.28 and production method thereof |
| CN114058770A (en) * | 2021-11-02 | 2022-02-18 | 阳春新钢铁有限责任公司 | Production method of HRB600E high-strength anti-seismic steel bar |
| CN114411061A (en) * | 2022-01-14 | 2022-04-29 | 宝武集团鄂城钢铁有限公司 | High-strength anti-seismic steel bar and preparation method thereof |
| CN114875316A (en) * | 2022-04-26 | 2022-08-09 | 湖南华菱湘潭钢铁有限公司 | High-strength deformed steel bar HRB600 and production method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102534407A (en) * | 2012-01-13 | 2012-07-04 | 首钢水城钢铁（集团）有限责任公司 | Production method for HRB600 hot-rolled ribbed steel bars |
| CN107747061A (en) * | 2017-09-14 | 2018-03-02 | 河钢股份有限公司 | A kind of 630MPa levels high-strength tenacity hot rolled ribbed bars and its production method |
| CN110343962A (en) * | 2019-07-26 | 2019-10-18 | 马鞍山钢铁股份有限公司 | A kind of 700Mpa grades or more hot-rolled ribbed high tensile reinforcement steel and its production method |
| CN110938777A (en) * | 2019-10-12 | 2020-03-31 | 河钢股份有限公司承德分公司 | Hot-rolled ribbed steel bar for 700 MPa-grade high-strength anchor rod and production method |
| CN111519099A (en) * | 2020-01-11 | 2020-08-11 | 武钢集团昆明钢铁股份有限公司 | Vanadium-chromium microalloyed large-size 500MPa ultrafine crystal corrosion-resistant anti-seismic reinforcing steel bar and preparation method thereof |
-
2020
- 2020-06-03 CN CN202010495496.XA patent/CN111575587A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102534407A (en) * | 2012-01-13 | 2012-07-04 | 首钢水城钢铁（集团）有限责任公司 | Production method for HRB600 hot-rolled ribbed steel bars |
| CN107747061A (en) * | 2017-09-14 | 2018-03-02 | 河钢股份有限公司 | A kind of 630MPa levels high-strength tenacity hot rolled ribbed bars and its production method |
| CN110343962A (en) * | 2019-07-26 | 2019-10-18 | 马鞍山钢铁股份有限公司 | A kind of 700Mpa grades or more hot-rolled ribbed high tensile reinforcement steel and its production method |
| CN110938777A (en) * | 2019-10-12 | 2020-03-31 | 河钢股份有限公司承德分公司 | Hot-rolled ribbed steel bar for 700 MPa-grade high-strength anchor rod and production method |
| CN111519099A (en) * | 2020-01-11 | 2020-08-11 | 武钢集团昆明钢铁股份有限公司 | Vanadium-chromium microalloyed large-size 500MPa ultrafine crystal corrosion-resistant anti-seismic reinforcing steel bar and preparation method thereof |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112375974A (en) * | 2020-10-28 | 2021-02-19 | 南京钢铁股份有限公司 | Deformed steel bar produced by high-chromium molten iron and preparation method thereof |
| CN112981259A (en) * | 2021-02-08 | 2021-06-18 | 青海西钢特殊钢科技开发有限公司 | HRB400E ribbed steel bar produced by substituting vanadium with chromium and method |
| CN113441545A (en) * | 2021-06-10 | 2021-09-28 | 广西柳钢华创科技研发有限公司 | HRB500E normal speed hot rolled ribbed steel bar with yield ratio more than 1.28 and production method thereof |
| CN113441545B (en) * | 2021-06-10 | 2023-03-03 | 广西柳钢华创科技研发有限公司 | HRB500E plain-speed hot-rolled ribbed steel bar with strength-to-yield ratio of more than 1.28 and production method thereof |
| CN114058770A (en) * | 2021-11-02 | 2022-02-18 | 阳春新钢铁有限责任公司 | Production method of HRB600E high-strength anti-seismic steel bar |
| CN114411061A (en) * | 2022-01-14 | 2022-04-29 | 宝武集团鄂城钢铁有限公司 | High-strength anti-seismic steel bar and preparation method thereof |
| CN114875316A (en) * | 2022-04-26 | 2022-08-09 | 湖南华菱湘潭钢铁有限公司 | High-strength deformed steel bar HRB600 and production method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11649516B2 (en) | Method for manufacturing thin-specification high-Ti wear-resistant steel NM450 | |
| CN111575587A (en) | Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying | |
| CN110952037B (en) | 400MPa hot-rolled refractory steel bar and manufacturing method thereof | |
| CN110106446B (en) | 400 MPa-grade Ti-containing hot-rolled ribbed steel bar and production process thereof | |
| CN103173682B (en) | Hot rolled strip for conveying concrete and manufacturing method thereof | |
| CN101654761A (en) | Carbon-manganese composite microalloyed steel for engineering machinery and preparation method thereof | |
| CN112011737B (en) | 390 MPa-grade-20-DEG C-resistant hot-rolled angle steel for bridge structure and production method thereof | |
| CN102424933A (en) | Hot-rolled high-strength strip steel and manufacturing method thereof | |
| CN110205550B (en) | 400 MPa-grade Cr and Ti-containing hot-rolled ribbed steel bar and production process thereof | |
| CN102703805A (en) | Normalized ship plate steel and production method thereof | |
| CN101307414A (en) | Steel for high performance manganese-containing engineering machinery wheel and method for preparing same | |
| CN104131238B (en) | High molding high durable Ultra-thin hot rolled steel plate and CSP production technology thereof | |
| CN109161671A (en) | A kind of Large Heat Input Welding high intensity EH36 steel plate and its manufacturing method | |
| CN110819892A (en) | Niobium-nitrogen-containing microalloyed HRB400E steel bar and production method thereof | |
| CN107099730B (en) | A kind of manufacturing method of the high Ti anti-wear steel NM360s of Thin Specs | |
| CN102864377B (en) | Hot rolled strip steel and manufacturing method thereof | |
| CN103540839B (en) | A kind of spherical tank is without the production method of Cr high-strength hardened and tempered steel plate | |
| CN101967604B (en) | Boron-nitrogen composite microalloyecd steel allowing for high heat input welding and manufacturing method | |
| CN111471936A (en) | Improved steel for agricultural machinery cutting tool and production method thereof | |
| CN111101070A (en) | Steel for low-temperature liquid container tank car and preparation method thereof | |
| CN103540842B (en) | A kind of spherical tank is without the production method of Cr high-strength hardened and tempered steel plate | |
| CN105624552B (en) | A kind of V, Ti, Cr, Ni, Cu microalloy high strength steel and its smelting process | |
| CN112981259A (en) | HRB400E ribbed steel bar produced by substituting vanadium with chromium and method | |
| CN112359171A (en) | Method for titanium-nitrogen alloying of molten steel in steelmaking process | |
| CN114855087B (en) | High-purity spring flat steel and smelting method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200825 |
|
| RJ01 | Rejection of invention patent application after publication |