CN110819891A - Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof - Google Patents
Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof Download PDFInfo
- Publication number
- CN110819891A CN110819891A CN201910974394.3A CN201910974394A CN110819891A CN 110819891 A CN110819891 A CN 110819891A CN 201910974394 A CN201910974394 A CN 201910974394A CN 110819891 A CN110819891 A CN 110819891A
- Authority
- CN
- China
- Prior art keywords
- steel
- niobium
- molten steel
- vanadium
- nitrogen
- 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
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
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention discloses a niobium-nitrogen microalloying HRB500E steel bar and a production method thereof, wherein the invention utilizes the strengthening effect of niobium and nitrogen on the steel bar to partially replace solid solution strengthening elements of manganese and silicon, partially or completely replace microalloying element of vanadium, simultaneously utilizes cheap nitrogen to carry out microalloying treatment on the steel bar, and utilizes the precipitation strengthening effect of trace niobium and nitrogen, and the Rel of the product produced by the invention is 530-580MPa, Rm is 700-780MPa, A is 22-33%, Rm/Rel is 1.30-1.42, the cold bending qualification rate is 100%, and the welding carbon equivalent is less than or equal to 0.48. The performance index of the steel bar produced by the method far exceeds the GB/T1499.2-2018 standard requirement; compared with the traditional method, the comprehensive production cost is reduced by 30-100 yuan/ton, the natural aging is carried out for three months, the fluctuation values of Rel and Rm are less than 10MPa, and the welding performance is good.
Description
Technical Field
The invention relates to a niobium and nitrogen containing microalloyed steel bar and a production process thereof, in particular to a niobium and nitrogen containing microalloyed HRB500E steel bar and a production process thereof.
Background
At present, three major production processes are available for HRB500 MPa-level steel bars.
The first is the design of carbon-manganese steel system with 20MnSi as basic component, manganese and silicon alloying with manganese system and silicon system iron alloy, vanadium microalloying with vanadium iron or vanadium-nitrogen alloy, or niobium microalloying with niobium-iron alloy alone, or composite alloying with niobium and vanadium alone, and conventional rolling process with non-controlled rolling and controlled cooling, and with Mn controlled by its main component]Between 1.2 and 1.6% [ Si ]]Between 0.40-0.80% [ C ]]Between 0.17 and 0.25% [ V ]]Controlled between 0.085-0.12% or [ Nb%]The content of niobium and vanadium is controlled to be between 0.080 and 0.10 percent, or the content of niobium and vanadium is controlled to be between 0.090 and 0.13 percent, and the national standard requirements of GB/T1499.2-2018 are as follows: rel is more than or equal to 500MPa, Rm is more than or equal to 630MPa, A is more than or equal to 15 percent, Rm/Rel is more than or equal to 1.25, AgtThe method is the most traditional and mature HRB500E steel bar production method, has stable product quality and good service performance, but has the problems that ① silicon manganese and carbon content are high, higher vanadium or niobium or vanadium-niobium compound is needed, alloy cost is increased, ② easily generates element segregation in the solidification and cooling processes, ③ carbon equivalent is higher, welding performance is poorer, ④ easily generates yield unobvious and mixed crystal phenomena, ⑤ is easy to generate yield-free platform and brittle fracture when being singly used for microalloying, quality defects such as casting blank cracks, stripping and the like and even steel leakage accidents occur when the continuous casting speed exceeds 3 m/min, ⑥ Rm/Rel is more than or equal to 1.25, A is equal to or more than 1.25, and A is equal to or more than 3 m/mingtThe qualification rate of more than or equal to 9 percent is below 95 percent.
The second is that the components are controlled according to the lower limit even lower than the lower limit of the components, the using amount of vanadium or niobium is greatly reduced, the low-temperature large-deformation rolling is adopted to produce the ultra-fine grain steel, the alloy components can be reduced, and the grain refinement is used as the improvement of the reinforcing steel barThe main means of strength is that the method is still in the industrial test popularization stage at present, and the method has the defects that ① needs to greatly increase the capability of a rolling mill, the equipment investment is greatly increased, the fixed asset investment is greatly increased by transforming an old rolling mill, ② produced steel bars cannot be welded conventionally, otherwise the strength of the steel bars is greatly reduced due to the growth of crystal grains in a welding area, the yield ratio of ③ steel bars is reduced, the proportion of Rm/Rel is more than or equal to 1.25 is below 95 percent, the percent of pass of the earthquake resistance index is low, and ④ total elongation A is ④gtThe proportion of more than or equal to 9 percent is less than 96 percent.
The third kind is that the components are controlled at the lower limit even lower than the lower limit, and the alloy components can be greatly reduced by using little or no vanadium and niobium, and the pre-through water cooling and the forced water cooling after rolling are adopted between the middle rolling and the finish rolling, but the method is commonly used at present, but if the through water cooling strength is too small, the performance of the steel bar can not reach the specified value of the national standard or the required value of a client, if the through water cooling strength is too large, the method is in conflict with the national standard, especially the national new standard implemented in 2018, such as the surface metallographic structure, the surface hardness and the core hardness are poor, the new national standard requirements can not be met, the service performance is adversely affected, and the ① needs to be added with water passing equipment, the investment and operation cost are increased, the natural aging shows that the performance of the steel bar is seriously fluctuated, the ③ welding performance is poor, the ④ steel bar is easy to be corroded, the proportion of Rm/Rel is not more than 1.25 and is below 90%, the shock resistance index qualification rate is very low, the ⑤ surface structure is not consistent with the core structure, the martensite and the national standard, the national tempering rate of the national steel bar 539 can easily meet the requirement of the general tempering standardgtThe proportion of more than or equal to 9 percent is less than 92 percent.
Based on the situation, the invention provides HRB500E component design and a production process thereof, wherein trace pure niobium content and trace nitrogen are used as microalloying elements, or niobium plus trace vanadium composite and trace nitrogen are used as microalloying elements, so that the aim of producing HRB500E steel bars by microalloying low niobium and trace vanadium plus nitrogen or trace pure niobium plus nitrogen microalloying is fulfilled, meanwhile, the steel bar structure meets the national standard requirement, the performance index far exceeds the national standard requirement, and the cost is lower than that of the traditional process.
Disclosure of Invention
The invention aims to provide a HRB500E component design and a production process thereof, wherein the HRB500E component design takes low pure niobium content and trace nitrogen as microalloying elements, or takes niobium plus trace vanadium compounding and trace nitrogen as microalloying elements.
In order to achieve the purpose, the invention adopts the technical scheme that blast furnace molten iron or one or two of the blast furnace molten iron and scrap steel or pig iron blocks are added into a converter for oxygen blowing smelting or an electric furnace for oxygen blowing and power transmission smelting, and a slagging agent is added; the scheme specifically comprises the following steps:
1) adding a proper amount of reducing manganese oxide pellets when oxygen is blown into a converter for smelting for 5-12min or when pig iron or scrap steel is added into an electric furnace;
2) adding a proper amount of reductive niobium oxide pellets or a proper amount of a mixture of reductive vanadium oxide pellets and reductive niobium oxide pellets within 3-5min before tapping of the converter; or adding a proper amount of reductive niobium oxide pellets into a steel ladle during electric furnace steel tapping, or adding a proper amount of a mixture of reductive vanadium oxide pellets and niobium oxide pellets;
3) adding a proper amount of one or a combination of a manganese alloy and metal manganese into the molten steel at the smelting end point within 20-130 seconds from the beginning of tapping of the converter according to the manganese content in the molten steel at the smelting end point and the target requirement range of the smelting component manganese of HRB500E steel, and adding a proper amount of one or a combination of a silicon alloy and metal silicon into the molten steel at the smelting end point according to the silicon content in the molten steel at the smelting end point and the target requirement range of the smelting component silicon of HRB500E steel; adding a proper amount of carburant according to the carbon content in molten steel at the smelting end point and considering the carbon content brought by other alloys, so that the mass percentage content of carbon in the molten steel reaches the target requirement range of HRB500E steel smelting components;
or according to the content of silicon and manganese in the molten steel after the molten steel of the electric furnace is subjected to LF refining and the target requirement range of the smelting components of silicon and manganese of HRB500E steel, adding one or a combination of a plurality of silicon series alloys and metal silicon in an appropriate amount and one or a combination of a plurality of manganese series alloys and metal manganese in an appropriate amount into the LF refining furnace to finely adjust the content of silicon and manganese, so that the mass percentage content ratio of silicon and manganese in the molten steel reaches the target requirement range of the smelting components of HRB500E steel, and according to the carbon content of the molten steel of the LF furnace and the carbon content brought into the alloy, adding an appropriate amount of carburant, so that the mass percentage content of carbon in the molten steel reaches the target requirement range of the smelting components of HRB500E steel;
4) blowing a proper amount of nitrogen or adding a proper amount of nitrogen-series alloy into the molten steel in a ladle under the condition of a microwave field in the converter tapping process and a molten steel blowing stirring station to ensure that the nitrogen content in the molten steel reaches the target requirement range of HRB500E steel smelting components;
or blowing a proper amount of nitrogen or adding a proper amount of nitrogen alloy into the molten steel in the ladle in an LF refining station of an electric furnace under the condition of a microwave field to ensure that the nitrogen content in the molten steel reaches the target requirement range of HRB500E steel smelting components;
5) adding a proper amount of one or a combination of more of vanadium alloy, metal vanadium and vanadium oxide and/or a proper amount of one or a combination of more of ferrocolumbium, metal niobium and niobium oxide into the molten steel in a ladle according to the contents of vanadium and niobium in the molten steel at the end point of the converter and the target range of the steel bar smelting components HRB500E in the tapping process of the converter, so that the content of vanadium and/or niobium in the molten steel reaches the target range of the steel bar smelting components HRB 500E;
or in the molten steel of an LF refining station of an electric furnace, the contents of vanadium and niobium and HRB500E steel bar smelting component target values are added into the molten steel in a ladle, and a proper amount of one or a combination of more of vanadium series alloy, metal vanadium and vanadium oxide and/or a proper amount of one or a combination of more of ferrocolumbium, metal niobium and niobium oxide are/is added into the molten steel in the ladle, so that the content of vanadium and/or niobium in the molten steel reaches the HRB500E steel bar smelting component target requirement range;
after the steps, the content targets of various elements in the molten steel in percentage by mass are finally controlled as follows: mn is more than or equal to 1.10 wt% and less than or equal to 1.50 wt%, Si is more than or equal to 0.30 wt% and less than or equal to 0.70 wt%, C is more than or equal to 0.18 wt% and less than or equal to 0.25 wt%, and N is more than or equal to 0.0130 wt% and less than 0.0190 wt%;
when the Nb in the molten steel does not contain V, the following conditions are satisfied: nb is more than or equal to 0.040 weight percent and less than 0.060 weight percent;
when the molten steel contains V and Nb simultaneously, the following conditions are satisfied: v + Nb is more than or equal to 0.045 wt% and less than 0.065 wt%;
6) the molten steel is cast into steel billets with different section sizes through a continuous casting machine, the steel billets are sent to a heating furnace in a hot mode or in a cold mode after being off-line, the steel billets are heated through the heating furnace and then rolled into reinforcing steel bars with different specifications, the cooling is controlled after the rolling process and the rolling, the temperature of the reinforcing steel bars on a cooling bed is 870-960 ℃, then the reinforcing steel bars are subjected to air cooling, cut to length, bundled and packaged, and finally the HRB500E finished reinforcing steel bars containing niobium-nitrogen microalloying are obtained.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; according to the contents of vanadium and niobium in the steelmaking water at the smelting end point of the converter and the smelting target component content range of steel, adding a proper amount of one or more of ferrovanadium, vanadium-nitrogen alloy, metal vanadium, ferroniobium and metal niobium during tapping, and finely adjusting the contents of vanadium and niobium in the steelmaking water to enable the mass percentage contents of all the elements to reach the target range; or according to the content ranges of vanadium and niobium in molten steel refined by an LF furnace after tapping of an electric furnace and the smelting target component content range of steel, adding a proper amount of one or more of ferrovanadium, vanadium-nitrogen alloy, metal vanadium, ferroniobium alloy and metal niobium, and finely adjusting the content of vanadium and niobium in the molten steel to ensure that the mass percentage content of each element reaches the target range; in the converter tapping process and the molten steel blowing stirring station, or in the electric furnace LF process, under the microwave field condition, blowing a proper amount of nitrogen or adding a proper amount of one or a combination of a plurality of micro nitrogen alloy, rare earth nitrogen alloy, silicon nitride, silicon iron nitride, silicon manganese nitride, titanium nitride and chromium nitride into the molten steel in the steel ladle, so that the mass percentage content of nitrogen elements reaches the target requirement range of HRB500E steel bar smelting components.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; the reducing vanadium oxide pellet is formed by sintering vanadium oxide at low temperature after internal carbon preparation, the reducing niobium oxide pellet is formed by sintering niobium oxide at low temperature after internal carbon preparation, and the reducing manganese oxide pellet is formed by sintering manganese oxide at low temperature after internal carbon preparation.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; the recarburizing agent is one or a combination of more of graphite-like, petroleum coke, carbon powder, silicon carbide and calcium carbide; the manganese alloy is one or a combination of manganese-iron alloy and silicon-manganese alloy; the silicon alloy is one or a combination of more of ferrosilicon, silicon-calcium alloy, silicon-carbon alloy and silicon carbide; the vanadium alloy is ferrovanadium, vanadium-nitrogen alloy, nitrided ferrovanadium and silicon-vanadium alloy; the nitrogen alloy is one or a combination of a plurality of micro nitrogen alloy, rare earth nitrogen alloy, silicon nitride, silicon iron nitride, silicon manganese nitride, titanium nitride and chromium nitride.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; the molten iron is steel-making molten iron meeting the national standard or semisteel molten steel obtained by vanadium extraction of vanadium-titanium molten iron.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; the nitrogen blowing intensity in the step 4) is 0.07-0.6m3And (5) t steel, and the nitrogen blowing time is controlled to be 2-6 min.
The invention relates to a preparation method of niobium-nitrogen-containing microalloyed HRB500E steel bar; and 6) pouring molten steel into steel billets with different section sizes through a continuous casting machine, heating the steel billets through a heating furnace, wherein the heating temperature is between 1000-1250 ℃, the initial rolling temperature is between 930-1180 ℃, pre-water-penetration cooling or non-pre-water-penetration cooling is adopted between a middle rolling unit and a finishing rolling unit, and the final rolling temperature is between 950-1100 ℃, and after rolling, cooling or air cooling is controlled to control the temperature of the cooling bed on the steel bars to be between 870-960 ℃.
The invention relates to a niobium-nitrogen-containing microalloyed HRB500E steel bar, which is prepared from molten steel containing various elements in the following mass content: mn is more than or equal to 1.10 wt% and less than or equal to 1.50 wt%, Si is more than or equal to 0.30 wt% and less than or equal to 0.70 wt%, C is more than or equal to 0.18 wt% and less than or equal to 0.25 wt%, and N is more than or equal to 0.0130 wt% and less than 0.0190 wt%;
when Nb is contained in the molten steel and V is not contained, the following conditions are satisfied: nb is more than or equal to 0.040 weight percent and less than 0.060 weight percent;
when the molten steel contains V and Nb simultaneously, the content of V + Nb is more than or equal to 0.045 wt% and less than 0.065 wt%.
The niobium-nitrogen-containing microalloyed HRB500E steel bar has the following performances: rel is between 530 and 580MPa, Rm is between 700 and 780MPa, A is between 22 and 33 percent, Agt is between 11 and 18 percent, Rm/Rel is between 1.30 and 1.42, the cold bending percent of pass is 100 percent, and Ceq is less than or equal to 0.48 percent.
As a preferred scheme, according to the market price change of niobium alloy and vanadium alloy, the invention can adopt niobium-nitrogen microalloying or niobium-vanadium-nitrogen microalloying; when the proportion and the dosage of V, Nb are properly controlled, the reduction range of the production cost of the steel bar of the designed process is far larger than that of other schemes; in addition, reducing manganese oxide pellets and niobium oxide pellets or vanadium oxide and niobium oxide pellets are added at the later stage of converter blowing, or reducing manganese oxide pellets and niobium oxide pellets or vanadium oxide and niobium oxide pellets are added in an LF process of electric furnace smelting, and the oxides are reduced into simple substances for alloying in the converter smelting or LF smelting process, so that the use amount of manganese alloy, ferroniobium alloy or ferrovanadium alloy is greatly reduced, the narrow-range control of HRB500E components can be realized, and the production cost is reduced on the premise of improving the steel performance.
The HRB500E steel bar tissue produced by the invention meets the GB/T1499.2-2018 standard requirements, and the performance index of the steel bar far exceeds the GB/T1499.2-2018 standard requirements.
The invention fully utilizes the precipitation strengthening and phase change effects of niobium and nitrogen on the steel bar, partially replaces solid solution strengthening elements of manganese and silicon, simultaneously utilizes the low-cost nitrogen element to carry out micro-alloying treatment on the steel bar, fully utilizes the precipitation strengthening effect of trace nitrogen, greatly reduces the dosage of strategic precious metal elements such as vanadium, niobium and the like, and realizes the production of the HRB500E high-strength-level steel bar with high strength level, stable quality and market popularity at low cost. Under the condition of the existing steel bar production equipment, a carbon-manganese component system is adopted, a smelting process of direct alloy alloying of reductive oxidation pellets and fine adjustment of components of iron alloy is adopted, nitrogen molecules are ionized by a microwave field, nitrogen microalloying is carried out on molten steel by bottom blowing or adding nitrogen increasing alloy, Rm of the HRB 500E-grade steel bar produced by the method is between 700-780MPa, A is between 22 and 33 percent, and A is between 700 and 780MPagt11-18 percent of the cold bending percent, Rm/Rel is 1.30-1.42 percent, the cold bending percent of pass is 100 percent, and Ceq is less than or equal to 0.48 percent. Aging for three months, leading the fluctuation values of Rel and Rm to be less than 10MPa,the welding performance is good; compared with the traditional method, the comprehensive cost is reduced by 30-100 yuan/ton; by using the existing equipment conditions, no new equipment investment is needed.
Detailed Description
The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.
The invention can adopt the process of oxygen converter smelting-continuous casting-rolling, and also can adopt the process of electric furnace smelting-continuous casting-rolling. The specific embodiment of the invention is implemented by adopting the processes of oxygen converter smelting, continuous casting and rolling.
Example 1
Adding blast furnace molten iron and scrap steel or pig iron blocks into a converter with the nominal capacity of 80 tons respectively, blowing oxygen for smelting, adding slag-making materials such as lime, adding a proper amount of reductive manganese oxide pellets 5min before blowing steel in the converter, and adding a proper amount of reductive niobium oxide pellets 3min before blowing steel in the converter to ensure that [ C ] in the molten steel at the smelting end point]0.12-0.15%, [ Mn%]Between 0.15 and 0.25% [ Nb ]]Between 0.005 and 0.010%; adding a proper amount of reductive vanadium oxide pellets within 2min before tapping of the converter to ensure that the V in the molten steel]Between 0.005 and 0.010 percent, other components such as molten steel with the sulfur content of less than 0.035 percent and the phosphorus content of less than 0.035 percent meet the standard requirements, and the steel is tapped when the temperature meets the requirements of the continuous casting process; adding a proper amount of ferromanganese alloy and manganese metal according to the manganese content in molten steel at the smelting end point 20 seconds after tapping to ensure that the manganese content in the molten steel is between 1.10 and 1.15 percent, adding a proper amount of ferrosilicon alloy, silicon carbide and silicon calcium alloy according to the silicon content in the molten steel at the smelting end point to ensure that the silicon content in the molten steel is between 0.65 and 0.70 percent, and adding a proper amount of carburant carbon powder, graphite-like and petroleum coke according to the target carbon content and considering the carbon content brought by other alloys to ensure that the [ C ] in the molten steel]Between 0.22 and 0.25 percent, blowing proper amount of nitrogen and adding proper amount of rare earth nitrogen alloy, titanium nitride and chromium nitride into the steel ladle and the molten steel through a microwave field in the tapping process and the molten steel blowing and stirring process to ensure that the [ N ] in the molten steel]The content is 0.013-0.0140%, and the nitrogen blowing strength is 0.07m3Steel is treated in a/min, and the nitrogen blowing time is controlled to be 6 min; adding a proper amount of ferrocolumbium and metal in the middle tapping periodNiobium to [ Nb ] in molten steel]Fine adjustment is made to [ Nb ] in molten steel]Adding proper amount of ferrovanadium and metal vanadium and vanadium-nitrogen alloy between 0.020% and 0.025% to make V in molten steel]Fine adjustment is performed to make [ V ] in molten steel]Between 0.020 and 0.025%.
The molten steel is poured into a billet with the cross section of 150X150mm by a continuous casting machine, the billet is hot-fed into a heating furnace and heated by the heating furnace, then the billet is rolled into a steel product with the diameter of 18mm by three-step cutting, the heating temperature is 1040 +/-20 ℃, the initial rolling temperature is 970 +/-20 ℃, pre-through water cooling is not needed between a medium rolling mill set and a finishing rolling mill set, the final rolling temperature is 970 +/-20 ℃, air cooling is carried out after rolling, the tempering temperature of a cooling bed on the steel bar is controlled to be 950 +/-10 ℃, and the steel bar is cut, packaged and warehoused according to the requirements of users.
The steel bar smelting chemical composition comprises the following components: 0.25% for C, 1.13% for Mn, 0.68% for Si, 0.0133% for N, 0.024% for Nb, and 0.022% for V. The performance indexes are as follows: four groups of tensile test samples and two groups of cold bending test samples are taken, wherein the four groups of tensile test results comprise that Rel is 530MPa, Rm is 700MPa, A is 32.8, and A isgt＝17.6％，Rm/Rel＝1.32；Rel＝540MPa，Rm＝730MPa，A＝31.2,Agt＝17.2％，Rm/Rel＝1.35；Rel＝545MPa，Rm＝725MPa，A＝32.5，Agt＝17.8％，Rm/Rel＝1.33；Rel＝540MPa，Rm＝740MPa，A＝31.6，Agt17.4%, Rm/Rel 1.37; two groups of cold-bending sample channels 1800All cold bending tests are qualified, and Ceq is less than 0.43 percent. The comprehensive cost is reduced by 84.6 yuan/ton. Aging for three months, the fluctuation value of Rel and Rm values is 5MPa, the welding performance is good, the steel bar structure is uniform, the steel bar structure is a ferrite and pearlite structure, and the hardness difference between the surface layer and the core part meets the new national standard requirement.
Example 2
Adding blast furnace molten iron and scrap steel or pig iron blocks into a converter with the nominal capacity of 100 tons respectively, blowing oxygen for smelting, adding slag-making materials such as lime, adding reductive manganese oxide pellets when the converter blows for 11min, and adding reductive niobium oxide pellets 4min before converter tapping; the content of [ C ] in molten steel at the smelting end point is between 0.08 and 0.15 percent, the content of [ Mn ] is between 0.15 and 0.20 percent, and the content of [ Nb ] is between 0.005 and 0.010 percent; the temperature and other components meet the standard requirements for tapping; 60 seconds after tapping, adding silicomanganese alloy and ferromanganese according to the Mn content in the molten steel at the smelting end point to ensure that the manganese content in the steel is between 1.10 and 1.15 percent, adding ferrosilicon alloy and metallic silicon according to the Si content in the molten steel at the smelting end point to ensure that the silicon content in the steel is between 0.30 and 0.40 percent, and adding carburant silicon carbide and carbon powder according to the target carbon content and considering the carbon content brought by other alloys to ensure that the carbon content in the steel is between 0.22 and 0.25 percent;
adding micro-nitrogen alloy, silicon-manganese nitride alloy, silicon-nitrogen alloy and manganese nitride in the tapping process and the molten steel blowing and stirring process to ensure that the nitrogen content in the molten steel is between 0.0155 and 0.0165 percent and the nitrogen blowing strength is 0.10m3Steel is treated in a/min, and the nitrogen blowing time is controlled to be 5 min;
according to the niobium content in the steelmaking water at the smelting end point of the converter, niobium-iron alloy is added during tapping to finely adjust the niobium content in the molten steel, so that the niobium content in the molten steel is between 0.040 and 0.045 percent.
The molten steel is cast into a steel billet with the section of 160X160mm by a continuous casting machine, the steel billet is hot-fed into a heating furnace and heated by the heating furnace, then the steel billet is cut and rolled into steel with the diameter of 20mm twice, the heating temperature is 1230 +/-20 ℃, the initial rolling temperature is 1160 +/-20 ℃, water penetration and pre-water penetration cooling are adopted between intermediate rolling and finish rolling, the final rolling temperature is 1090 +/-10 ℃, water penetration cooling is carried out after rolling, the temperature of a steel bar on a cooling bed is controlled to be 880 +/-10 ℃, and the steel bar is cut to package and warehoused according to the requirement of a user.
The steel bar comprises the following chemical components: c is 0.25%, Mn is 1.13%, Si is 0.31%, N is 0.0158%, and Nb is 0.043%. The performance indexes are as follows: two groups of tensile test samples and one group of cold bending test samples are taken together, and the results of the two groups of tensile test samples are that Rel is 560MPa, Rm is 780MPa, A is 28.4, Agt＝14.1％，Rm/Rel＝1.39；Rel＝555MPa，Rm＝780MPa，A＝28.5,Agt14.6%, Rm/Rel 1.41; a set of cold-bending sample channels 1800The cold bending test is qualified, and Ceq is less than 0.42%. The comprehensive cost is reduced by 98.9 yuan/ton. Aging for three months, leading the fluctuation values of Rel and Rm to be less than 10MPa and leading the welding performance to be good. The steel bar has uniform structure, is a ferrite and pearlite structure, and the hardness difference between the surface layer and the core part meets the new national standard requirement.
Example 3
Adding blast furnace molten iron and scrap steel or pig iron blocks into a converter with the nominal capacity of 120 tons respectively, blowing oxygen for smelting, adding slag-making materials such as lime and the like, adding a proper amount of reductive manganese oxide pellets when the converter blows for 8min, adding a proper amount of mixture of reductive niobium oxide pellets and reductive vanadium oxide pellets when the converter taps for 5min, so that the [ C ] in the molten steel at the smelting end point is between 0.10 and 0.15 percent, [ Mn ] is between 0.12 and 0.20 percent, [ V ] is between 0.005 and 0.010 percent and [ Nb ] is between 0.005 and 0.010 percent; other components such as molten steel with the sulfur content of less than 0.035%, phosphorus content of less than 0.035% and the like meet the standard requirements, and the steel is tapped when the temperature meets the requirements of the continuous casting process; adding proper amount of silicon-manganese alloy and ferromanganese alloy according to Mn content in molten steel at smelting end point to make manganese content in molten steel be 1.40-1.50%, adding proper amount of ferrosilicon alloy according to Si content in molten steel at smelting end point to make silicon content in molten steel be 0.45-0.50%, adding proper amount of carburant calcium carbide and coke according to target carbon content and considering carbon content brought by other alloys to make C in molten steel be 0.18-0.23%,
during the tapping process and the molten steel blowing and stirring process, proper amount of micro nitrogen alloy, RE nitrogen alloy and manganese nitride are added into the molten steel to increase the nitrogen content in the molten steel]The content is 0.0165-0.0185%, and the nitrogen blowing strength is 0.6m3Steel is treated in a/min, and the nitrogen blowing time is controlled to be 2 min;
adding ferrocolumbium and niobium oxide in the middle tapping stage to finely adjust the Nb in the molten steel to ensure that the Nb in the molten steel is between 0.025 and 0.030 percent, and simultaneously adding ferrovanadium nitride, silicon-vanadium alloy and vanadium oxide to ensure that the V in the molten steel is between 0.035 and 0.040 percent.
The molten steel is cast into a billet with the section of 165X165mm by a continuous casting machine, the billet is hot-fed into a heating furnace and heated by the heating furnace, then the billet is rolled into a steel with the diameter of 14mm by four-segmentation, the heating temperature is 1130 +/-20 ℃, the initial rolling temperature is 1060 +/-20 ℃, water penetration and pre-water penetration cooling are not needed between intermediate rolling and finish rolling, the final rolling temperature is 1060 +/-10 ℃, water penetration cooling is carried out after rolling, the temperature of a steel bar on a cooling bed is controlled to be 950 +/-10 ℃, and the steel bar is cut to be packaged and stored according to the requirement of a user.
The steelThe tendon comprises the following chemical components: c is 0.18%, Mn is 1.48%, Si is 0.47%, N is 0.0175%, Nb is 0.028%, and V is 0.036%. The performance indexes are as follows: two groups of tensile test samples and one group of cold bending test samples are taken together, and the results of the two groups of tensile test samples are that Rel is 580MPa, Rm is 765MPa, A is 22.5, A isgt＝11.6％，Rm/Rel＝1.31；Rel＝580MPa，Rm＝770MPa，A＝22.3,Agt12.1%, Rm/Rel 1.32; set of cold bending test specimens 1800The cold bending test is qualified, and Ceq is less than 0.43 percent. The comprehensive cost is reduced by 32.2 yuan/ton. Aging for three months, leading the fluctuation value of Rel and Rm values to be 10MPa and leading the welding performance to be good. The steel bar has uniform structure, is a ferrite and pearlite structure, and the hardness difference between the surface layer and the core part meets the new national standard requirement.
Example 4
Blast furnace molten iron and scrap steel or pig iron blocks are respectively added into a converter with the nominal capacity of 120 tons, oxygen is blown for smelting, slagging materials such as lime and the like are added, a proper amount of reductive manganese oxide pellets are added when the converter is blown for 12min, a proper amount of reductive niobium oxide pellets are added 5min before the converter is tapped, so that [ C ] in the molten iron at the smelting end point is between 0.10 and 0.15 percent, [ Mn ] is between 0.10 and 0.20 percent, and [ Nb ] is between 0.008 and 0.012 percent; the other components meet the standard requirements, and the steel is tapped when the sulfur content of the molten steel of the converter is less than 0.035%, the phosphorus content is less than 0.035%, and the temperature meets the requirements of the continuous casting process.
Adding a proper amount of silicon-manganese alloy and metal manganese according to the Mn content in molten steel at the smelting end point to ensure that the manganese content in the steel is between 1.10 and 1.15 percent at 70 seconds after tapping, adding a proper amount of silicon-iron alloy, metal and silicon carbide according to the Si content in the molten steel at the smelting end point to ensure that the silicon content in the steel is between 0.65 and 0.70 percent, and adding a proper amount of carburant carbon powder and graphite-like according to the target carbon content and considering the carbon content brought by other alloys to ensure that the carbon content in the steel is between 0.23 and 0.25 percent;
blowing proper amount of nitrogen gas in the molten steel blowing and stirring station under the condition of microwave field, simultaneously adding proper amount of micro nitrogen alloy, silicon nitride iron and silicon manganese nitride to finely adjust the nitrogen content, so that the nitrogen content in the molten steel is between 0.0160 and 0.0170 percent, and the nitrogen gas blowing strength is 0.3m3Steel is treated in a/min, and the nitrogen blowing time is controlled to be 4 min;
according to the niobium content in the steelmaking water at the smelting end point of the converter, a proper amount of niobium-iron alloy and niobium oxide are added during tapping to finely adjust the niobium content in the molten steel, so that the niobium content in the molten steel is between 0.04 and 0.05 percent.
The molten steel is cast into a steel billet with the section of 160X160mm by a continuous casting machine, the steel billet is sent to a heating furnace after being cooled off the line and is heated by the heating furnace, then the steel billet is rolled into a steel product with the diameter of 28mm, the heating temperature is 1180 +/-20 ℃, the initial rolling temperature is 1110 +/-20 ℃, pre-through water cooling is started between intermediate rolling and finish rolling, the final rolling temperature is 1050 +/-10 ℃, water cooling is carried out after rolling, the temperature of a cooling bed on the steel bar is controlled to be 940 +/-10 ℃, and the steel bar is cut to be packaged and stored according to the requirement of a user.
The steel bar comprises the following chemical components: 0.25% for C, 1.12% for Mn, 0.70% for Si, 0.0163% for N, and 0.049% for Nb. The performance indexes are as follows: two groups of tensile test samples and one group of cold bending test samples are taken together, and the results of the two groups of tensile test samples are that Rel is 565MPa, Rm is 755MPa, A is 26.5, Agt＝16.6％，Rm/Rel＝1.35；Rel＝565MPa，Rm＝760MPa，A＝27.3,Agt16.1%, Rm/Rel 1.35; set of cold bending test specimens 1800The cold bending test is qualified, and Ceq is less than 0.44%. The comprehensive cost is reduced by 77.6 yuan/ton. Aging for three months, leading the fluctuation values of Rel and Rm to be less than 6MPa and leading the welding performance to be good. The steel bar has uniform structure, is a ferrite and pearlite structure, and the hardness difference between the surface layer and the core part meets the new national standard requirement.
Example 5
Adding blast furnace molten iron, scrap steel and pig iron blocks or scrap steel and pig iron blocks into an electric furnace with the engineering capacity of 80 tons, blowing oxygen and transmitting electricity for smelting, adding a slagging agent, and adding furnace materials such as lime, coke particles or other carburants, reducing manganese oxide pellets and the like when pig iron or scrap steel is added into the electric furnace; feeding power, and simultaneously blowing carbon powder and oxygen into the furnace for fluxing; after melting down, decarbonizing, making oxidation slag, dephosphorizing and deslagging; and tapping after phosphorus and carbon in the molten steel meet the steel grade requirement.
Adding a proper amount of reducing niobium oxide pellets into a steel ladle during electric furnace tapping; after LF refining is carried out on electric furnace molten steel, according to the content of silicon and manganese in the molten steel, a proper amount of silicon carbide, metal manganese, silicon-manganese alloy, ferrosilicon alloy, metal silicon and the like are added into an 80-ton LF refining furnace to finely adjust the content of silicon and manganese, so that the mass percentage of silicon and manganese in the molten steel reaches a target, the content of manganese is 1.15-1.20%, the content of silicon is 0.55-0.65%, and according to the carbon content of the molten steel in the LF furnace and the carbon content brought into the alloy, a proper amount of carburant carbon powder is added, so that the mass percentage of carbon in the molten steel reaches the target 0.20-0.24%; adding a proper amount of micro-nitrogen alloy, rare earth nitrogen alloy and ferrosilicon nitride into an LF refining station of an electric furnace to ensure that the nitrogen content in the molten steel reaches the requirement of a target control range and is between 0.0185 and 0.0190 percent.
In the later stage of LF refining, a proper amount of niobium-iron alloy and niobium oxide are added according to the content of niobium in molten steel in a ladle and the target content of HRB500E niobium to finely adjust the content of niobium in the molten steel, so that the content of niobium in the molten steel is between 0.055 and 0.06 percent.
The molten steel is cast into a billet with the cross section of 150X150mm by a continuous casting machine, the billet is hot-fed into a heating furnace and heated by the heating furnace, then rolled into a steel product with the diameter of 32mm by a continuous rolling mill set, the heating temperature is 1210 +/-20 ℃, the initial rolling temperature is 1130 +/-20 ℃, pre-through water cooling is adopted between intermediate rolling and finish rolling, the final rolling temperature is 1060 +/-10 ℃, through water cooling is carried out after rolling, the temperature of a steel bar on a cooling bed is controlled to be 880 +/-10 ℃, and the steel bar is cut to be packaged and stored according to the requirements of users.
The steel bar comprises the following chemical components: c is 0.22%, Mn is 1.19%, Si is 0.61%, N is 0.0188%, and Nb is 0.059%. The performance indexes are as follows: four groups of tensile test samples and two groups of cold bending test samples are taken, wherein the results of the four groups of tensile test samples are that Rel is 560MPa, Rm is 750MPa, A is 27.8, and A isgt＝15.2％，Rm/Rel＝1.34；Rel＝565MPa，Rm＝750MPa，A＝27.5,Agt＝15.2％，Rm/Rel＝1.33；Rel＝560MPa，Rm＝750MPa，A＝27.5，Agt＝15.8％，Rm/Rel＝1.34；Rel＝565MPa，Rm＝755MPa，A＝27.6，Agt15.4%, Rm/Rel 1.34; two groups of cold-bending sample channels 1800The cold bending tests are all qualified, and the comprehensive cost is reduced by 57.2 yuan/ton. Aging for three months, leading the fluctuation value of Rel and Rm values to be 5MPa and leading the welding performance to be good. The steel bar has uniform structure, is ferrite and pearlite structure, and the hardness difference between the surface layer and the core part meets the new national standardAnd (6) obtaining.
The inventors have tried to work without following the procedure designed by the present invention, but the effect is not good. Meanwhile, compared with the existing HRB500E steel bar added with vanadium or niobium independently, the HRB500E steel bar designed and prepared by the invention has obvious advantages in performance.
Claims (9)
1. A production method of niobium-nitrogen-containing microalloyed HRB500E steel bars is characterized in that blast furnace molten iron, or blast furnace molten iron and one or two of scrap steel or pig iron are added into a converter for oxygen blowing smelting, or are added into an electric furnace for oxygen blowing and power transmission smelting, and a slag former is added; the method is characterized by comprising the following steps:
1) blowing oxygen in a converter for smelting for 5-12min, or adding reducing manganese oxide pellets when pig iron or scrap steel is added into an electric furnace;
2) adding a proper amount of reductive niobium oxide pellets or a proper amount of a mixture of reductive vanadium oxide pellets and reductive niobium oxide pellets within 3-5min before tapping of the converter; or adding a proper amount of reductive niobium oxide pellets into a steel ladle during electric furnace steel tapping, or adding a proper amount of a mixture of reductive vanadium oxide pellets and niobium oxide pellets;
3) adding a proper amount of one or a combination of a manganese alloy and metal manganese into the molten steel at the smelting end point within 20-130 seconds from the beginning of tapping of the converter according to the manganese content in the molten steel at the smelting end point and the target requirement range of the smelting component manganese of HRB500E steel, and adding a proper amount of one or a combination of a silicon alloy and metal silicon into the molten steel at the smelting end point according to the silicon content in the molten steel at the smelting end point and the target requirement range of the smelting component silicon of HRB500E steel; adding a proper amount of carburant according to the carbon content in molten steel at the smelting end point and considering the carbon content brought by other alloys, so that the mass percentage content of carbon in the molten steel reaches the target requirement range of HRB500E steel smelting components;
or according to the content of silicon and manganese in the molten steel after the molten steel of the electric furnace is subjected to LF refining and the target requirement range of the smelting components of silicon and manganese of HRB500E steel, adding one or a combination of a plurality of silicon series alloys and metal silicon in an appropriate amount and one or a combination of a plurality of manganese series alloys and metal manganese in an appropriate amount into the LF refining furnace to finely adjust the content of silicon and manganese, so that the mass percentage content ratio of silicon and manganese in the molten steel reaches the target requirement range of the smelting components of HRB500E steel, and according to the carbon content of the molten steel of the LF furnace and the carbon content brought into the alloy, adding an appropriate amount of carburant, so that the mass percentage content of carbon in the molten steel reaches the target requirement range of the smelting components of HRB500E steel;
4) blowing a proper amount of nitrogen or adding a proper amount of nitrogen-series alloy into the molten steel in a ladle under the condition of a microwave field in the converter tapping process and a molten steel blowing stirring station to ensure that the nitrogen content in the molten steel reaches the target requirement range of HRB500E steel smelting components;
or blowing a proper amount of nitrogen or adding a proper amount of nitrogen alloy into the molten steel in the ladle in an LF refining station of an electric furnace under the condition of a microwave field to ensure that the nitrogen content in the molten steel reaches the target requirement range of HRB500E steel smelting components;
5) adding one or a combination of a plurality of proper amounts of vanadium alloy, metal vanadium and vanadium oxide or one or a combination of a plurality of proper amounts of ferrocolumbium, metal niobium and niobium oxide into the molten steel in a ladle according to the contents of vanadium and niobium in the molten steel at the end point of the converter and the target range of the steel bar smelting components HRB500E in the tapping process of the converter, so that the contents of vanadium and niobium in the molten steel reach the target range of the steel bar smelting components HRB 500E;
or in the molten steel of an LF refining station of an electric furnace, the contents of vanadium and niobium and the target value of HRB500E steel bar smelting components are added into the molten steel in a ladle, and a proper amount of one or a combination of a plurality of vanadium series alloy, metal vanadium and vanadium oxide or a proper amount of one or a combination of a plurality of ferroniobium, metal niobium and niobium oxide is added into the molten steel in the ladle, so that the contents of vanadium and niobium in the molten steel reach the target requirement range of HRB500E steel bar smelting components;
after the steps, the content targets of various elements in the molten steel in percentage by mass are finally controlled as follows: mn is more than or equal to 1.10 wt% and less than or equal to 1.50 wt%, Si is more than or equal to 0.30 wt% and less than or equal to 0.70 wt%, C is more than or equal to 0.18 wt% and less than or equal to 0.25 wt%, and N is more than or equal to 0.0130 wt% and less than 0.0190 wt%;
when Nb is contained in the molten steel and V is not contained, the following conditions are satisfied: nb is more than or equal to 0.040 weight percent and less than 0.060 weight percent;
when the molten steel contains V and Nb simultaneously, the following requirements are met: v + Nb is more than or equal to 0.045 wt% and less than 0.065 wt%;
6) the molten steel is poured into steel billets with different section sizes by adopting a continuous casting machine, the steel billets are sent to a heating furnace in a hot-rolling or cold-rolling way after being taken off the line, the steel billets are heated by the heating furnace and then rolled into reinforcing steel bars with different specifications, the cooling is controlled after the rolling process and the rolling, the temperature of a cooling bed on the reinforcing steel bars is 870-960 ℃, then the finished reinforcing steel bars containing the niobium-nitrogen microalloying HRB500E are obtained after air cooling, cut to length, bundling and packaging.
2. The method of claim 1, wherein:
according to the contents of vanadium and niobium in the steelmaking water at the smelting end point of the converter and the smelting target component content range of HRB500E steel bars, adding a proper amount of one or a combination of a plurality of vanadium series alloy, metal vanadium and vanadium oxides and/or a proper amount of one or a combination of a plurality of ferroniobium, metal niobium and niobium oxides during tapping, and finely adjusting the contents of vanadium and/or niobium in the steelmaking water to enable the mass percentage contents of all the elements to reach the target ranges;
or adding a proper amount of one or a combination of a plurality of vanadium series alloy, metal vanadium and oxide of vanadium and/or a proper amount of one or a combination of a plurality of ferrocolumbium, metal niobium and oxide of niobium according to the content of vanadium and niobium in molten steel refined by an LF furnace after tapping of an electric furnace and the content range of smelting target components of HRB500E steel bars, and finely adjusting the content of vanadium and/or niobium in the molten steel;
blowing a proper amount of nitrogen or adding a proper amount of nitrogen alloy into the molten steel in a ladle under the microwave field condition in the converter tapping process and molten steel blowing stirring station or in an electric furnace LF procedure to ensure that the mass percentage content of nitrogen reaches the target requirement range of HRB500E steel bar smelting components; meanwhile, other alloy elements except nitrogen elements in the various alloys are considered to be in the smelting target component range of the HRB500E steel bar.
3. The method of claim 1, wherein: the reducing vanadium oxide pellet is formed by sintering vanadium oxide at low temperature after internal carbon preparation, the reducing niobium oxide pellet is formed by sintering niobium oxide at low temperature after internal carbon preparation, and the reducing manganese oxide pellet is formed by sintering manganese oxide at low temperature after internal carbon preparation.
4. The method of claim 1, wherein: the recarburizing agent is one or a combination of more of graphite-like, petroleum coke, carbon powder, silicon carbide and calcium carbide; the manganese alloy is one or a combination of manganese-iron alloy and silicon-manganese alloy; the silicon alloy is one or a combination of silicon-iron alloy, silicon-calcium alloy, silicon-carbon alloy and silicon carbide; the vanadium alloy is ferrovanadium, vanadium-nitrogen alloy, nitrided ferrovanadium and silicon-vanadium alloy; (ii) a The nitrogen alloy is one or a combination of a plurality of micro nitrogen alloy, rare earth nitrogen alloy, silicon nitride, silicon iron nitride, silicon manganese nitride, titanium nitride and chromium nitride.
5. The method according to claim 1, wherein the molten iron is molten steel for steel making or semi-molten steel after vanadium extraction of molten vanadium-titanium iron which meets national standards.
6. The method of claim 1, wherein: the nitrogen blowing intensity in the step 4) is 0.07-0.6m3And (5) t steel, and the nitrogen blowing time is controlled to be 2-6 min.
7. The method of claim 1, wherein: and 6) casting molten steel into steel billets with different section sizes through a continuous casting machine, carrying out hot delivery or cold delivery of the steel billets to a heating furnace after the steel billets are taken off line, heating the steel billets through the heating furnace, wherein the heating temperature is between 1000-1250 ℃, the initial rolling temperature is between 930-1180 ℃, pre-through water cooling or non-pre-through water cooling is adopted between a middle rolling unit and a finishing rolling unit, the final rolling temperature is between 950-1100 ℃, and after rolling, cooling or air cooling is controlled to control the temperature of a cooling bed on the steel bars to be between 870-960 ℃.
8. A niobium-nitrogen-containing microalloyed HRB500E steel bar is characterized in that: the steel is prepared from the following molten steel containing various elements in percentage by mass: mn is more than or equal to 1.10 wt% and less than or equal to 1.50 wt%, Si is more than or equal to 0.30 wt% and less than or equal to 0.70 wt%, C is more than or equal to 0.18 wt% and less than or equal to 0.25 wt%, and N is more than or equal to 0.0130 wt% and less than 0.0190 wt%;
when the molten steel contains Nb and does not contain V, the Nb content is more than or equal to 0.040 wt% and less than 0.060 wt%;
when the molten steel contains V and Nb simultaneously, the V + Nb content is more than or equal to 0.045 wt% and less than 0.065 wt%.
9. The niobium-nitrogen-containing microalloyed HRB500E steel bar as claimed in claim 8, wherein:
the performance of the niobium-nitrogen-containing microalloyed HRB500E steel bar meets the following requirements: rel is between 530-580MPa, Rm is between 700-780MPa, A is between 25-33 percent, A isgt11-18 percent of the cold bending percent, Rm/Rel is 1.30-1.42 percent, the cold bending percent of pass is 100 percent, and Ceq is less than or equal to 0.48 percent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910974394.3A CN110819891A (en) | 2019-10-14 | 2019-10-14 | Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910974394.3A CN110819891A (en) | 2019-10-14 | 2019-10-14 | Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110819891A true CN110819891A (en) | 2020-02-21 |
Family
ID=69549080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910974394.3A Pending CN110819891A (en) | 2019-10-14 | 2019-10-14 | Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110819891A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111876667A (en) * | 2020-06-24 | 2020-11-03 | 宣化钢铁集团有限责任公司 | HRB500E steel bar produced by micro-nitrogen alloy and production process thereof |
| CN112779460A (en) * | 2020-12-24 | 2021-05-11 | 武钢集团昆明钢铁股份有限公司 | Production method of HRB500E fine-grain high-strength anti-seismic anti-corrosion reinforcing steel bar |
| CN114657459A (en) * | 2022-02-21 | 2022-06-24 | 长沙东鑫环保材料有限责任公司 | Nitrogen-vanadium-titanium-niobium rare earth microalloying high-strength deep-drawing cold-rolled steel plate and production method thereof |
| CN114672724A (en) * | 2022-02-21 | 2022-06-28 | 长沙东鑫环保材料有限责任公司 | Rare earth and nitrogen microalloyed molybdenum-containing HRB500E disc spiral steel bar and production method thereof |
| CN115161536A (en) * | 2021-09-18 | 2022-10-11 | 广西柳州钢铁集团有限公司 | Hot rolled steel wire rod |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102383039A (en) * | 2011-11-10 | 2012-03-21 | 长沙东鑫环保材料有限责任公司 | Microalloy HRB500E steel bar containing chrome and nitrogen and production method thereof |
| JP2017137576A (en) * | 2016-01-29 | 2017-08-10 | Ｊｆｅスチール株式会社 | Angle steel and production method of angle steel |
| CN107955911A (en) * | 2017-11-30 | 2018-04-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Microalloy containing Nb builds steel bar and its LF stove production methods |
| CN107955919A (en) * | 2017-11-30 | 2018-04-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Steel bar and its LF stove production methods are built containing V, Nb microalloy |
| CN109576572A (en) * | 2018-11-16 | 2019-04-05 | 河钢股份有限公司承德分公司 | A kind of super-high strength steel muscle and its production method |
-
2019
- 2019-10-14 CN CN201910974394.3A patent/CN110819891A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102383039A (en) * | 2011-11-10 | 2012-03-21 | 长沙东鑫环保材料有限责任公司 | Microalloy HRB500E steel bar containing chrome and nitrogen and production method thereof |
| JP2017137576A (en) * | 2016-01-29 | 2017-08-10 | Ｊｆｅスチール株式会社 | Angle steel and production method of angle steel |
| CN107955911A (en) * | 2017-11-30 | 2018-04-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Microalloy containing Nb builds steel bar and its LF stove production methods |
| CN107955919A (en) * | 2017-11-30 | 2018-04-24 | 攀钢集团攀枝花钢铁研究院有限公司 | Steel bar and its LF stove production methods are built containing V, Nb microalloy |
| CN109576572A (en) * | 2018-11-16 | 2019-04-05 | 河钢股份有限公司承德分公司 | A kind of super-high strength steel muscle and its production method |
Non-Patent Citations (1)
| Title |
|---|
| 苏世怀等: "《热轧钢筋》", 30 September 2010, 冶金工业出版社 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111876667A (en) * | 2020-06-24 | 2020-11-03 | 宣化钢铁集团有限责任公司 | HRB500E steel bar produced by micro-nitrogen alloy and production process thereof |
| CN112779460A (en) * | 2020-12-24 | 2021-05-11 | 武钢集团昆明钢铁股份有限公司 | Production method of HRB500E fine-grain high-strength anti-seismic anti-corrosion reinforcing steel bar |
| CN115161536A (en) * | 2021-09-18 | 2022-10-11 | 广西柳州钢铁集团有限公司 | Hot rolled steel wire rod |
| CN115161536B (en) * | 2021-09-18 | 2023-07-14 | 广西柳州钢铁集团有限公司 | Hot rolled wire rod reinforcing steel bar |
| CN114657459A (en) * | 2022-02-21 | 2022-06-24 | 长沙东鑫环保材料有限责任公司 | Nitrogen-vanadium-titanium-niobium rare earth microalloying high-strength deep-drawing cold-rolled steel plate and production method thereof |
| CN114672724A (en) * | 2022-02-21 | 2022-06-28 | 长沙东鑫环保材料有限责任公司 | Rare earth and nitrogen microalloyed molybdenum-containing HRB500E disc spiral steel bar and production method thereof |
| CN114672724B (en) * | 2022-02-21 | 2023-03-10 | 长沙东鑫环保材料有限责任公司 | Rare earth and nitrogen microalloyed molybdenum-containing HRB500E disc spiral steel bar and production method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111004980B (en) | Vanadium-chromium microalloyed large-size 600MPa ultrafine-grain high-toughness corrosion-resistant anti-seismic steel bar and preparation method thereof | |
| CN110819891A (en) | Niobium-nitrogen-containing microalloyed HRB500E steel bar and production method thereof | |
| KR101484106B1 (en) | Method for Controlling Extremely Low Ti in Extra Low Carbon AlSi-Killed Steel | |
| CN101418363B (en) | Production method of low-carbon high-toughness X60/X65 pipeline steel | |
| CN102383042B (en) | Microalloy HRB400E steel bar containing chrome and nitrogen and production method thereof | |
| CN110819892A (en) | Niobium-nitrogen-containing microalloyed HRB400E steel bar and production method thereof | |
| CN102330021A (en) | Full production process of low-temperature oriented silicon steel | |
| CN108568503B (en) | Method for accurately controlling carbon content of molten steel in 600MPa dual-phase steel tundish | |
| CN111575587A (en) | Method for producing HRB600 high-strength hot-rolled ribbed steel bar by vanadium-chromium microalloying | |
| CN113862577B (en) | Production method of high-strength low-yield-ratio welded gas cylinder steel | |
| CN113462972A (en) | Quenching and tempering high-strength low-temperature-resistant H-shaped steel for ocean engineering and preparation method thereof | |
| CN111926236B (en) | Method for producing steel plate with excellent Z-direction performance for welding structure by adopting continuous casting billet under condition of small compression ratio | |
| CN101660095A (en) | Manufacturing method of atmosphere corrosion resistance steel | |
| CN112962025A (en) | Production method of low-cost flaw-detection-guaranteed low-alloy structural steel medium plate | |
| CN102978511B (en) | Method for producing hot-rolled steel plate for automobile girder steel by low cost | |
| CN113403523B (en) | Production process for producing steel for automobile door hinge by converter | |
| CN116716544B (en) | Round steel for ocean engineering and preparation method thereof | |
| CN111304404B (en) | Cored wire for oxide metallurgy of vacuum induction furnace and use method | |
| CN117127115A (en) | Rare earth carbonitride precipitation strengthening high-strength hot-rolled anti-seismic HRB640E steel bar and preparation method thereof | |
| CN114657460A (en) | HRB400E spiral reinforcement steel wire rod processed by microalloying rare earth and nitrogen and production method thereof | |
| CN102453786A (en) | Method for smelting steel for drill rod joint by using rotating furnace, and steel for drill rod joint | |
| CN109136766A (en) | A kind of corrosion resistant mooring chain steel and preparation method thereof | |
| CN115029614A (en) | Method for producing deformed steel bar by combining titanium-nitrogen composite strengthening and controlled rolling and controlled cooling | |
| CN114921713A (en) | Low-yield-ratio high-low-temperature-toughness steel plate and production method thereof | |
| CN107955910A (en) | Steel bar and its LF stove production methods are built containing V, Nb, Ti microalloy |
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 |