CN111020392B - Production method of low-alloy HRB400E steel bar - Google Patents
Production method of low-alloy HRB400E steel bar Download PDFInfo
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- CN111020392B CN111020392B CN201911295857.XA CN201911295857A CN111020392B CN 111020392 B CN111020392 B CN 111020392B CN 201911295857 A CN201911295857 A CN 201911295857A CN 111020392 B CN111020392 B CN 111020392B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 36
- 239000010959 steel Substances 0.000 title claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 25
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 23
- 239000000956 alloy Substances 0.000 title claims abstract description 23
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 11
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 8
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 8
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 8
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 3
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 3
- 229910052742 iron Inorganic materials 0.000 claims abstract description 3
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims abstract description 3
- 239000011574 phosphorus Substances 0.000 claims abstract description 3
- 239000010703 silicon Substances 0.000 claims abstract description 3
- 239000011593 sulfur Substances 0.000 claims abstract description 3
- 238000001816 cooling Methods 0.000 claims description 49
- 238000005266 casting Methods 0.000 claims description 33
- 238000005096 rolling process Methods 0.000 claims description 17
- 238000010438 heat treatment Methods 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 3
- 238000005272 metallurgy Methods 0.000 abstract description 2
- 239000011572 manganese Substances 0.000 description 7
- 229910052748 manganese Inorganic materials 0.000 description 6
- 230000009466 transformation Effects 0.000 description 3
- 229910001562 pearlite Inorganic materials 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C21D11/00—Process control or regulation for heat treatments
- C21D11/005—Process control or regulation for heat treatments for cooling
-
- 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
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- 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
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Metal Rolling (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention belongs to the technical field of metallurgy, and particularly relates to a production method of a low-alloy HRB400E steel bar. The steel bar comprises the following elements in percentage by weight: 0.20-0.25% of carbon, 0.20-0.50% of silicon, 1.0-1.20% of manganese, 0.015-0.035% of vanadium and 0.01-0.025% of nitrogen, and the balance of iron and inevitable impurity elements, wherein the content of phosphorus in the impurity elements is less than or equal to 0.035 wt%, and the content of sulfur in the impurity elements is less than or equal to 0.035 wt%. The vanadium content in the steel bar can be as low as 0.015 percent, so that the production cost can be reduced.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to a production method of a low-alloy HRB400E steel bar.
Background
HRB400E is a high-strength anti-seismic reinforcing steel bar and is widely applied to key projects such as bridges, buildings and ocean engineering with high requirements on safety performance. In order to ensure that the HRB400E steel bar has better mechanical property and welding property, an alloying mode of adding manganese (Mn) and vanadium (V) elements is generally adopted. Especially, after 2018, the national standard puts requirements on the metallographic structure of the steel bar, the traditional water-through quenching process is limited, and vanadium almost becomes a necessary alloy element. With the increase of the demand of steel bar production enterprises for vanadium, the vanadium price rises sharply, thereby increasing the cost of the HRB400E steel bar.
Disclosure of Invention
Aiming at the problem that the cost is increased due to the fact that vanadium is required to be added into HRB400E steel bars, the invention provides a low-alloy HRB400E steel bar.
The invention also provides a production method of the low-alloy HRB400E steel bar.
In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:
a low-alloy HRB400E steel bar comprises the following elements in percentage by weight: 0.20-0.25% of carbon, 0.20-0.50% of silicon, 1.0-1.20% of manganese, 0.015-0.035% of vanadium and 0.01-0.025% of nitrogen, and the balance of iron and inevitable impurity elements, wherein the content of phosphorus in the impurity elements is less than or equal to 0.035 wt%, and the content of sulfur in the impurity elements is less than or equal to 0.035 wt%.
The weight percentage content of vanadium in the steel bar can be as low as 0.015 percent, so that the production cost can be reduced. Meanwhile, the steel bar has good mechanical properties, and can meet the requirements of the anti-seismic steel bar on yield strength, tensile strength, elongation after fracture, maximum force elongation and yield ratio.
The embodiment of the invention also provides a production method of the low-alloy HRB400E steel bar, which comprises the following steps:
s1, heating a casting blank containing elements in the HRB400E steel bar to 950-990 ℃, wherein the inside and outside temperature difference of the casting blank is less than or equal to 15 ℃;
s2, rolling the heated casting blank, wherein the rolling temperature and the final rolling temperature are both 850-950 ℃, and obtaining a finished product;
s3, cooling the finished product material to 585-615 ℃ at a first cooling rate of 45-55 ℃/min, and cooling to a final cooling temperature of 320-400 ℃ at a second cooling rate of 1.5-3.5 ℃/min.
The steps of the production method and the parameters in the steps are applied to a cast slab containing the above elements, specifically: the production method firstly limits the heating temperature of the casting blank and the temperature difference between the inside and the outside of the casting blank in S1, so that the surface layer of the casting blank does not generate a closed-loop structure; the heating temperature at S1 and the rolling temperature and finish rolling temperature at S2 can prevent coarse grains from adversely affecting the overall mechanical properties; then, two-step cooling is adopted in S3, firstly, the transformation of cold austenite in a casting blank is avoided through the rapid cooling of a first cooling rate, such as the precipitation of proeutectoid ferrite and the transformation of high-temperature pearlite with larger lamellar spacing; and then, the material is slowly cooled at a second cooling rate, so that the material has sufficient time to be transformed in a pearlite transformation zone, bainite or martensite is prevented from being formed due to too high cooling speed, vanadium carbonitride has sufficient time to be precipitated, and the strength and toughness of the steel are improved. According to the production method, the contents of all elements in the casting blank are combined, the heating temperature, the rolling temperature and the finish rolling temperature are limited in the rolling process, the rapid cooling and the slow cooling are adopted, and the cooling rate and the cooling temperature are limited, so that the produced steel bar still has excellent mechanical properties under the condition of reducing the alloy usage amount, the yield strength is more than or equal to 455MPa, the tensile strength is more than or equal to 650MPa, the elongation after fracture is more than or equal to 26%, the maximum force elongation is more than or equal to 14.5%, and the strength-to-yield ratio is more than or equal to 1.41. The production method reduces the consumption of the alloy in the HRB400E steel bar, and greatly reduces the production cost.
After the final cooling temperature is reached in S3, any cooling rate and cooling method may be used, and cooling methods such as air cooling, water cooling, and air cooling may be selected according to actual production conditions during production, without any restriction.
Preferably, the cross section of the casting blank is a rectangle with the side length of 150-165 mm.
Preferably, the diameter of the finished product is 14-25 mm.
Preferably, the first cooling rate is 55 ℃/min.
Preferably, the second cooling rate is 2.5 ℃/min.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Example 1
The embodiment provides a low-alloy HRB400E steel bar, which comprises the following elements in percentage by weight: c: 0.24%, Si: 0.22%, Mn: 1.10%, V: 0.016%, N: 0.020%, P: 0.020%, S: 0.015% and the balance Fe. The production method comprises the following steps:
s1, heating the casting blank containing the elements to 975 ℃, wherein the temperature difference between the inside and the outside of the casting blank is 9 ℃; the cross section of the casting blank is a square with the side length of 150 mm;
s2, rolling the heated casting blank at 950 ℃ and 841 ℃ to obtain a finished product with the diameter of 14 mm;
s3, cooling the finished product material to 610 ℃ at a first cooling rate of 51 ℃/min, and then cooling to 400 ℃ at a second cooling rate of 3.5 ℃/min.
Example 2
The embodiment provides a low-alloy HRB400E steel bar, which comprises the following elements in percentage by weight: c: 0.21%, Si: 0.23%, Mn: 1.00%, V: 0.021%, N: 0.025%, P: 0.031%, S: 0.035%, and the balance Fe. The production method comprises the following steps:
s1, heating the casting blank containing the elements to 990 ℃, wherein the temperature difference between the inside and the outside of the casting blank is 15 ℃; the cross section of the casting blank is a square with the side length of 165 mm;
s2, rolling the heated casting blank at 880 ℃ and 930 ℃ to form a finished product with the diameter of 18 mm;
s3, cooling the finished product material to 605 ℃ at a first cooling rate of 55 ℃/min, and then cooling to 380 ℃ at a second cooling rate of 2.7 ℃/min.
Example 3
The embodiment provides a low-alloy HRB400E steel bar, which comprises the following elements in percentage by weight: c: 0.20%, Si: 0.25%, Mn: 1.20%, V: 0.025%, N: 0.021%, P: 0.035%, S: 0.021%, and the balance Fe. The production method comprises the following steps:
s1, heating the casting blank containing the elements to 950 ℃, wherein the temperature difference between the inside and the outside of the casting blank is 7 ℃; the cross section of the casting blank is a square with the side length of 150 mm;
s2, rolling the heated casting blank at 940 ℃ and 950 ℃ to obtain a finished product with the diameter of 16 mm;
s3, cooling the finished product material to 598 ℃ at a first cooling rate of 48 ℃/min, and then cooling to 370 ℃ at a second cooling rate of 3.2 ℃/min.
Example 4
The embodiment provides a low-alloy HRB400E steel bar, which comprises the following elements in percentage by weight: c: 0.25%, Si: 0.20%, Mn: 1.12%, V: 0.015%, N: 0.010%, P: 0.019%, S: 0.008% and the balance Fe. The production method comprises the following steps:
s1, heating the casting blank containing the elements to 963 ℃, wherein the temperature difference between the inside and the outside of the casting blank is 12 ℃; the cross section of the casting blank is a square with the side length of 165 mm;
s2, rolling the heated casting blank at 850 ℃ and 870 ℃ to obtain a finished product with the diameter of 25 mm;
s3, cooling the finished product material to 600 ℃ at a first cooling rate of 50 ℃/min, and then cooling to 391 ℃ at a second cooling rate of 1.5 ℃/min.
Example 5
The embodiment provides a low-alloy HRB400E steel bar, which comprises the following elements in percentage by weight: c: 0.23%, Si: 0.21%, Mn: 1.14%, V: 0.023%, N: 0.017%, P: 0.013%, S: 0.023 percent and the balance of Fe. The production method comprises the following steps:
s1, heating the casting blank containing the elements to 982 ℃, wherein the temperature difference between the inside and the outside of the casting blank is 11 ℃; the cross section of the casting blank is a square with the side length of 150 mm;
s2, rolling the heated casting blank at the rolling temperature of 910 ℃ and the finishing temperature of 850 ℃ to obtain a finished product with the diameter of 20 mm;
s3, cooling the finished product material to 615 ℃ at a first cooling rate of 45 ℃/min, and then cooling to 320 ℃ at a second cooling rate of 1.9 ℃/min.
Examination example
The results of mechanical property examination of the HRB400E steel bars obtained in examples 1 to 5 are shown in Table 1.
TABLE 1 mechanical Properties of the finished products
Item | Example 1 | Example 2 | Example 3 | Example 4 | Example 5 |
Yield strength/MPa | 463 | 475 | 490 | 459 | 460 |
Tensile strength/MPa | 658 | 679 | 692 | 653 | 651 |
Elongation after rupture/%) | 29 | 27 | 26 | 28 | 27 |
Maximum force elongation/%) | 14.5 | 14.7 | 14.6 | 15.2 | 14.8 |
Ratio of yield to strength | 1.42 | 1.43 | 1.41 | 1.42 | 1.42 |
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (5)
1. A production method of a low-alloy HRB400E steel bar is characterized in that the low-alloy HRB400E steel bar comprises the following elements by weight percent: 0.20-0.25% of carbon, 0.20-0.50% of silicon, 1.0-1.20% of manganese, 0.015-0.035% of vanadium and 0.01-0.025% of nitrogen, and the balance of iron and inevitable impurity elements, wherein the content of phosphorus in the impurity elements is less than or equal to 0.035 wt%, and the content of sulfur in the impurity elements is less than or equal to 0.035 wt%;
the production method of the low-alloy HRB400E steel bar specifically comprises the following steps:
s1, heating a casting blank containing elements in the HRB400E steel bar to 950-990 ℃, wherein the inside and outside temperature difference of the casting blank is less than or equal to 15 ℃;
s2, rolling the heated casting blank, wherein the rolling temperature and the final rolling temperature are both 850-950 ℃, and obtaining a finished product;
s3, cooling the finished product material to 585-615 ℃ at a first cooling rate of 45-55 ℃/min, and cooling to a final cooling temperature of 320-400 ℃ at a second cooling rate of 1.5-3.5 ℃/min.
2. A production method of a low-alloy HRB400E steel bar according to claim 1, wherein the cross section of the casting blank is a rectangle with 150-165 mm side length.
3. A production method of a low-alloy HRB400E steel bar according to claim 1, wherein the diameter of the finished product is 14-25 mm.
4. A method of producing a low alloy HRB400E steel bar as claimed in claim 1, wherein the first cooling rate is 48 ℃/min.
5. A method of producing a low alloy HRB400E steel bar as claimed in claim 4, wherein the second cooling rate is 3.2 ℃/min.
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