CN107287506B - 650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof - Google Patents
650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof Download PDFInfo
- Publication number
- CN107287506B CN107287506B CN201610200259.XA CN201610200259A CN107287506B CN 107287506 B CN107287506 B CN 107287506B CN 201610200259 A CN201610200259 A CN 201610200259A CN 107287506 B CN107287506 B CN 107287506B
- Authority
- CN
- China
- Prior art keywords
- percent
- temperature
- stage
- rolling
- equal
- 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.)
- Active
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 70
- 239000010959 steel Substances 0.000 title claims abstract description 70
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 238000005096 rolling process Methods 0.000 claims abstract description 39
- 238000005496 tempering Methods 0.000 claims abstract description 10
- 239000000126 substance Substances 0.000 claims abstract description 9
- 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
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 7
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 6
- 238000004321 preservation Methods 0.000 claims abstract description 6
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims abstract description 4
- 238000010438 heat treatment Methods 0.000 claims description 14
- 238000005266 casting Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 12
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 11
- 229910052750 molybdenum Inorganic materials 0.000 claims description 7
- 238000009749 continuous casting Methods 0.000 claims description 5
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 238000003723 Smelting Methods 0.000 claims description 3
- 229910052748 manganese Inorganic materials 0.000 claims description 3
- 238000007689 inspection Methods 0.000 claims description 2
- 230000001186 cumulative effect Effects 0.000 abstract description 2
- 229910045601 alloy Inorganic materials 0.000 description 8
- 239000000956 alloy Substances 0.000 description 8
- 229910001566 austenite Inorganic materials 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 239000002893 slag Substances 0.000 description 6
- 238000005292 vacuum distillation Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 239000006104 solid solution Substances 0.000 description 5
- 239000010936 titanium Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 4
- 238000001953 recrystallisation Methods 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 230000001914 calming effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- GFNGCDBZVSLSFT-UHFFFAOYSA-N titanium vanadium Chemical compound [Ti].[V] GFNGCDBZVSLSFT-UHFFFAOYSA-N 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 229910001182 Mo alloy Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000003137 locomotive effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003204 osmotic effect Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
-
- 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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses a 650 MPa-level medium-temperature and medium-pressure boiler steel plate and a production method thereof, wherein the steel comprises the following chemical components in percentage by weight: 0.15 to 0.23 percent of C, 0.15 to 0.40 percent of Si, 1.20 to 1.60 percent of Mn1, less than or equal to 0.005 percent of S, less than or equal to 0.015 percent of P, 0.20 to 0.40 percent of Ni, 0.30 to 0.60 percent of Mo0, 0.01 to 0.02 percent of Ti, 0.02 to 0.05 percent of V, 0.02 to 0.05 percent of Als, and the balance of Fe and inevitable impurities. The rolling adopts a two-stage normalizing rolling process, the initial rolling temperature of the first stage is more than or equal to 1100 ℃, the final rolling temperature is 1050-1000 ℃, the pass reduction rate of the first stage is 15-25%, and the thickness of the intermediate blank is 2-2.5 times that of a finished steel plate; and the initial rolling temperature of the stage II is 900-920 ℃, the final rolling temperature is 870-890 ℃, the cumulative reduction rate of the stage II is 50-65%, and the rolling is followed by air cooling. The tempering heat preservation temperature is 650-680 ℃, and the heat preservation time is 2-4 min/mm.
Description
Technical Field
The invention belongs to the metallurgical industry, and relates to steel for a boiler pressure container in a medium-temperature and medium-pressure environment and a production method thereof.
Background
The boiler is an energy conversion device, the energy input to the boiler is in the forms of chemical energy in fuel, electric energy, heat energy of high-temperature flue gas and the like, and steam, high-temperature water or an organic heat carrier with certain heat energy is output outwards after the conversion of the boiler, so that the boiler plays a very important role in national economic development for a long time, and is mainly used in the fields of thermal power stations, ships, locomotives, industrial and mining and the like. The medium-temperature and medium-pressure boiler container mainly refers to a boiler container facility with the use environment of 3.8MPa < pressure < 5.8MPa and 350 ℃ < temperature < 450 ℃, and because the boiler container is made of main steel materials, steel enterprises pay great attention to the development of boiler container steel plates.
The invention discloses a steel for a vanadium-titanium composite treatment boiler and a pressure vessel and a production method thereof (201010622957.1), which improve the strength of steel through vanadium-titanium composite treatment, but the disclosed steel for the boiler and the pressure vessel belongs to a grade with lower strength in a boiler vessel.
The invention discloses a low-alloy high-strength steel plate for a large-thickness boiler drum and a manufacturing method thereof (CN 103834873A). The components are added with alloy elements such as Cr, Ni, Mo, Nb and the like, and various properties of the steel plate are ensured through the traditional processes of ingot casting, rolling and offline heat treatment, and the process is complex and tedious.
The invention discloses a production process flow of a pressure vessel steel 18MnMoNbR and a plate with the thickness of 100mm (CN103160740A) and a paper published in a metal material and metallurgical engineering (development of an extra-thick 18MnMoNbR steel grade for a pressure vessel), which is basically characterized by comprising an electric furnace, die casting, rolling and heat treatment, wherein the component process meets the performance requirement of a steel plate, but the production process has the problems of complex manufacturing procedure, long production period and the like.
The invention patent disclosed above adds more noble metal elements in the component design to increase the cost, and some add less alloy elements but lower strength level; in the process, most of the cast steel ingots are used as raw materials, the production efficiency is low, the cost is high, and the heat treatment process basically adopts off-line normalizing and tempering, so that the process cost is further increased. In order to solve the problems in the patent, the invention aims to adopt a reasonable chemical composition design, namely, the carbon content is properly improved, Ni and Mo alloy elements and V, Ti micro alloy elements are added, the normal temperature and medium temperature strength of steel is enhanced, the production process cost is effectively reduced through a converter continuous casting, on-line normalizing rolling and off-line tempering production process route, and the normal temperature and medium temperature performance of the boiler steel plate at the level is ensured.
Disclosure of Invention
Aiming at the defects in the prior art, the invention obtains the boiler steel plate with excellent obdurability matching and excellent medium-temperature performance by brand-new chemical component design and adopting a production process route different from the traditional boiler container manufacturing process.
The technical scheme of the invention is as follows: the alloy composition of the steel is designed, and the steel comprises the following components in percentage by weight: 0.15 to 0.23 percent of C, 0.15 to 0.40 percent of Si, 1.20 to 1.60 percent of Mn, less than or equal to 0.005 percent of S, less than or equal to 0.015 percent of P, 0.20 to 0.40 percent of Ni, 0.30 to 0.60 percent of Mo, 0.01 to 0.02 percent of Ti, 0.02 to 0.05 percent of V, 0.02 to 0.05 percent of Als, and the balance of Fe and inevitable impurities;
the reasons for limiting the amounts of the alloying elements C, Si, Mn, P, S, Ni, Mo, Ti, V, Als in the steel sheet are as follows:
c is the most main element for improving the strength of the steel, improves the strength of the steel through solid solution strengthening and precipitation strengthening, improves the hardenability, and ensures the strength grade and the high-temperature performance of the steel; too high a carbon content will in turn affect the weldability of the steel. Therefore, the content of C is limited to 0.15% to 0.23% in the present invention.
Si is used as a reducing agent and a deoxidizer in the steelmaking process, and the combination of Si, Mo, Cr and the like has the effects of improving the corrosion resistance and oxidation resistance, and when the content exceeds 0.5 percent, the toughness of the steel is reduced, and the welding performance of the steel is reduced, so the content of Si is limited to 0.15 to 0.40 percent in the invention.
Mn can increase the toughness, strength and hardness of steel, is an element for strongly stabilizing austenite, can effectively reduce the decomposition speed of austenite and improve the hardenability of steel, and the tempering brittleness can be enhanced due to the high Mn content, so that the Mn content is controlled to be 1.20-1.60%.
S and P are harmful elements in steel, increase the brittleness of the steel, so the content of phosphorus and sulfur in the steel should be reduced as much as possible, and the content of S, P is respectively limited in the invention as follows: s is less than or equal to 0.005 percent and P is less than or equal to 0.015 percent.
Mo improves the hardenability of the steel, and when the content is about 0.5 percent, the tempering brittleness can be reduced, and the secondary hardening effect is achieved. The heat strength and creep strength are improved, but the steel is embrittled by excessively high Mo content, so that the Mo content is limited to 0.30-0.60% in the present invention.
Ni can improve the strength and toughness of the steel plate, has good hardenability, improves the plasticity and toughness and improves the corrosion resistance, is combined with molybdenum to enhance the heat strength, is one of main alloy elements of heat-strength steel and stainless acid-resistant steel, but the Ni content is limited to 0.20 to 0.40 percent due to higher cost
Ti has strong solid solution strengthening effect, but reduces the toughness of solid solution, improves the hardenability of steel by solid solution in austenite, improves the tempering stability, has secondary hardening effect, improves the oxidation resistance and the heat strength of the steel, such as creep deformation and endurance strength, and improves the weldability of the steel, so the content of Ti is limited to 0.01-0.02%.
V is solid-dissolved in austenite to improve hardenability of steel, but vanadium existing in a combined state lowers hardenability of steel, increases tempering stability of steel, has a strong secondary hardening effect, and has a strong solid-solution strengthening effect by solid-dissolving in ferrite, so that the V content is limited to 0.02% to 0.05%.
Als is a commonly used deoxidizer in steel. A small amount of aluminum is added into the steel, so that crystal grains can be refined, the impact toughness is improved, and the hot workability, the welding performance and the cutting workability of the steel are influenced if the aluminum content is too high, so that the content of Als is limited to 0.02-0.05 percent.
A production process of a 650 MPa-level medium-temperature medium-pressure boiler steel plate comprises the following steps: the method comprises the following steps of molten iron pretreatment, converter smelting, LF-RH, continuous casting, casting blank heating, rolling, heat treatment and inspection. Wherein,
the smelting process comprises the following steps: the steel making is carried out with molten iron desulphurization pretreatment, clean scrap steel is selected to ensure clean and dry alloy, slag is stopped and steel is tapped, the thickness of a slag layer is required to be less than or equal to 100mm, LF refining deep desulphurization treatment is adopted to produce reducing slag to ensure that impurities are fully floated, VD is adopted, the net cycle time of VD is more than or equal to 10min, and the calming time before casting is more than or equal to 3 min; the linear speed of feeding silicon and calcium by the LF furnace is more than or equal to 2m/s, and the linear feeding amount is more than or equal to 3-5 m/t;
the casting process comprises the following steps: and after vacuum is broken by VD, a continuous casting machine is adopted for casting, the superheat degree is less than 25 ℃, and the casting process needs to be stable and constant. The casting blank is inserted into a stack to be slowly cooled, and the stack is slowly cooled for more than 48 hours;
a heating process: by controlling the heating process of the steel billet, the alloy elements are ensured to be fully dissolved in solid, the growth of original austenite grains is effectively inhibited, the heating temperature of the plate blank is controlled to be 1150-1250 ℃, the heating time is 4-6 hours, and the soaking time is 0.5-1.0 hour;
the rolling process comprises the following steps: the rolling adopts a two-stage normalizing rolling process, the larger pass reduction rate in the stage I is ensured, the deformation fully permeates the core of the steel billet, austenite grains in a recrystallization zone are fully and uniformly refined, the starting temperature in the stage II is controlled, and the final rolling temperature is ensured to be Ac3+ (30-50) DEG C. The specific process parameters are as follows: the initial rolling temperature of the first stage is more than or equal to 1100 ℃, the final rolling temperature is 1050-1000 ℃, the pass reduction rate of the first stage is 15-25%, and the thickness of the intermediate blank is 2-2.5 times that of a finished steel plate; the initial rolling temperature of the stage II is 900-920 ℃, the final rolling temperature is 870-890 ℃, and the accumulated reduction rate of the stage II is 50-65%. And air cooling after rolling.
A heat treatment process: the steel plate after normalizing rolling does not obtain a final stable structure although crystal grains are refined, a more stable tempered bainite + ferrite structure with good obdurability matching is obtained through high-temperature tempering treatment, and the tempering process comprises the following steps: the heat preservation temperature is 650-680 ℃, and the heat preservation time is 2-4 min/mm.
In the production process of the invention:
the initial rolling temperature of the first stage is more than or equal to 1100 ℃, and the final rolling temperature is 1050-1000 ℃: the temperature range is an austenite recrystallization region, recrystallization grains are refined through deformation and recrystallization of the grains, and uniform and fine tissues are obtained after phase change.
The pass reduction rate of 15-25% is mainly to make the core of the billet obtain osmotic deformation and ensure the mechanical property of the steel plate.
The thickness of the intermediate blank is 2-2.5 times of that of the finished steel plate, and the total deformation rate of the II stage is ensured to be more than 50%, because the larger the total reduction rate is, the finer the ferrite crystal grains are, and the better the mechanical property of the steel plate is.
The second-stage rolling temperature is 900-920 ℃, and the final rolling temperature is 870-890 ℃: the temperature interval is Ac3+ (30-50) DEG C of steel, namely a normalizing temperature interval, and is a key temperature interval for ensuring the normalizing rolling.
50% -65% of the stage II cumulative reduction rate is to obtain fine original crystal grains.
Has the advantages that:
the invention has the beneficial effects that through the brand-new chemical composition design, the short-flow, low-cost and high-efficiency production process route different from the traditional boiler steel plate is adopted, wherein the normal temperature Rm is more than or equal to 650MPa and the KV at-20 ℃ is more than or equal to2Not less than 100J; r at 350 DEG CelR is more than or equal to 380MPa at 400 DEG CelR is more than or equal to 365MPa and 450 DEG CelThe normal temperature and medium temperature performance of the boiler steel plate is more than or equal to 350 MPa.
Detailed Description
The technical problem related to the invention is solved by adopting the following technical scheme: a650 MPa-level medium-temperature and medium-pressure boiler steel plate and a production method thereof are disclosed, which comprises the following chemical components in percentage by mass: 0.15 to 0.23 percent of C, 0.15 to 0.40 percent of Si, 1.20 to 1.60 percent of Mn1, less than or equal to 0.005 percent of S, less than or equal to 0.015 percent of P, 0.20 to 0.40 percent of Ni, 0.30 to 0.60 percent of Mo, 0.01 to 0.02 percent of Ti0.02, 0.02 to 0.05 percent of V, 0.02 to 0.05 percent of Als, and the balance of Fe and inevitable impurities; performing molten iron desulphurization pretreatment, wherein the thickness of a slag layer is required to be less than or equal to 100mm during slag stopping and tapping, performing LF refining deep desulphurization treatment to produce reducing slag and ensure that impurities float sufficiently, and adopting VD (vacuum distillation) for which the net cycle time is not less than 10min and the calming time before casting is not less than 3 min; the linear speed of feeding silicon and calcium by the LF furnace is more than or equal to 2m/s, and the linear feeding amount is more than or equal to 3-5 m/t; and after vacuum is broken by VD, a continuous casting machine is adopted for casting, the superheat degree is less than 25 ℃, and the casting process needs to be stable and constant. The casting blank is inserted into a stack to be slowly cooled, and the stack is slowly cooled for more than 48 hours; controlling the heating temperature of the casting blank to 1150-1250 ℃, heating for 4-6 hours, and soaking for 0.5-1.0 hour; the initial rolling temperature of the first stage is more than or equal to 1100 ℃, the final rolling temperature of the first stage is 1050-1000 ℃, the pass reduction rate of the first stage is 15-25%, and the thickness of the intermediate blank is 2-2.5 times that of a finished steel plate; the initial rolling temperature of the stage II is 900-920 ℃, the final rolling temperature is 870-890 ℃, and the accumulated reduction rate of the stage II is 50-65%. And air cooling after rolling.
The following examples are intended to illustrate the invention in detail, and are intended to be a general description of the invention, and not to limit the invention. Table 1 shows the chemical compositions of the steels of the examples of the invention, Table 2 shows the production process parameters of the steels of the examples of the invention, and Table 3 shows the mechanical properties of the steels of the examples of the invention.
Table 1 examples chemical composition (wt%)
Table 2 examples production process parameters
TABLE 3 mechanical Properties of the examples
According to the results, the normal temperature Rm of the medium-temperature and medium-pressure boiler steel plate provided by the invention is more than or equal to 665MPa and the KV at the temperature of-20 DEG C2The mass ratio is more than or equal to 144J; r at 350 DEG CelR is more than or equal to 384MPa at 400 DEG CelR is more than or equal to 365MPa and 450 DEG CelNot less than 351MPa, and excellent normal temperature and medium temperature performance.
Claims (1)
1. A production method of a 650 MPa-level medium-temperature medium-pressure boiler steel plate comprises the following steps: the method comprises the steps of molten iron pretreatment, converter smelting, LF-RH, continuous casting, casting blank heating, rolling, heat treatment and inspection, and is characterized in that,
the steel comprises the following chemical components in percentage by weight: 0.15 to 0.23 percent of C, 0.15 to 0.38 percent of Si, 1.20 to 1.55 percent of Mn, less than or equal to 0.005 percent of S, less than or equal to 0.015 percent of P, 0.20 to 0.38 percent of Ni, 0.30 to 0.59 percent of Mo, 0.01 to 0.02 percent of Ti, 0.02 to 0.045 percent of V, 0.02 to 0.037 percent of Als, and the balance of Fe and inevitable impurities;
the rolling adopts a two-stage normalizing rolling process, the initial rolling temperature of the first stage is more than or equal to 1100 ℃, the final rolling temperature is 1050-1000 ℃, the pass reduction rate of the first stage is 15-25%, and the thickness of the intermediate blank is 2-2.5 times that of a finished steel plate; and the initial rolling temperature of the stage II is 900-920 ℃, the final rolling temperature is 870-890 ℃, the accumulated reduction rate of the stage II is 50-65%, air cooling is carried out after rolling, the tempering heat preservation temperature is 650-680 ℃, and the heat preservation time is 2-4 min/mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610200259.XA CN107287506B (en) | 2016-03-31 | 2016-03-31 | 650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610200259.XA CN107287506B (en) | 2016-03-31 | 2016-03-31 | 650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107287506A CN107287506A (en) | 2017-10-24 |
| CN107287506B true CN107287506B (en) | 2019-02-26 |
Family
ID=60087629
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610200259.XA Active CN107287506B (en) | 2016-03-31 | 2016-03-31 | 650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107287506B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110669984B (en) * | 2019-09-30 | 2021-01-08 | 鞍钢股份有限公司 | 1000 MPa-level medium-temperature and ultrahigh-pressure boiler steel plate and production method thereof |
| CN110669985B (en) * | 2019-09-30 | 2021-01-08 | 鞍钢股份有限公司 | 750 MPa-level medium-temperature high-pressure boiler steel plate and production method thereof |
| CN110791703B (en) * | 2019-09-30 | 2021-04-02 | 鞍钢股份有限公司 | 850 MPa-level medium-temperature high-pressure boiler steel plate and production method thereof |
| CN110846593A (en) * | 2019-11-13 | 2020-02-28 | 甘肃酒钢集团宏兴钢铁股份有限公司 | Production method of medium-high temperature boiler and pressure vessel steel plate |
| CN111455255B (en) * | 2020-03-30 | 2022-05-06 | 江阴兴澄特种钢铁有限公司 | Preparation method of EH36 steel for extra-thick offshore wind power with thickness of 80-100mm |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101514434A (en) * | 2008-02-21 | 2009-08-26 | 宝山钢铁股份有限公司 | Thick steel plate for pressure vessel, method for manufacturing the same, use of the same |
| CN101821417A (en) * | 2007-09-19 | 2010-09-01 | 住友金属工业株式会社 | Low alloy steel for high-pressure hydrogen gas environment, and container for high-pressure hydrogen |
| CN101871077A (en) * | 2010-06-08 | 2010-10-27 | 武汉钢铁(集团)公司 | Normalizing type high-strength pressure vessel steel and manufacturing method thereof |
| CN102605296A (en) * | 2012-03-13 | 2012-07-25 | 宝山钢铁股份有限公司 | Steel for nuclear pressure vessels and manufacturing method thereof |
| CN102796967A (en) * | 2012-08-31 | 2012-11-28 | 济钢集团有限公司 | 800 MPa economic corrosion-resistance and high-strength steel plate |
| CN103160747A (en) * | 2011-12-14 | 2013-06-19 | 鞍钢股份有限公司 | Low-welding crack sensitivity off-line quenched and tempered super-thick steel plate and manufacturing method thereof |
| CN103667912A (en) * | 2013-12-30 | 2014-03-26 | 莱芜钢铁集团有限公司 | Low-alloy steel plate and heat treatment method for steel plate |
-
2016
- 2016-03-31 CN CN201610200259.XA patent/CN107287506B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101821417A (en) * | 2007-09-19 | 2010-09-01 | 住友金属工业株式会社 | Low alloy steel for high-pressure hydrogen gas environment, and container for high-pressure hydrogen |
| CN101514434A (en) * | 2008-02-21 | 2009-08-26 | 宝山钢铁股份有限公司 | Thick steel plate for pressure vessel, method for manufacturing the same, use of the same |
| CN101871077A (en) * | 2010-06-08 | 2010-10-27 | 武汉钢铁(集团)公司 | Normalizing type high-strength pressure vessel steel and manufacturing method thereof |
| CN103160747A (en) * | 2011-12-14 | 2013-06-19 | 鞍钢股份有限公司 | Low-welding crack sensitivity off-line quenched and tempered super-thick steel plate and manufacturing method thereof |
| CN102605296A (en) * | 2012-03-13 | 2012-07-25 | 宝山钢铁股份有限公司 | Steel for nuclear pressure vessels and manufacturing method thereof |
| CN102796967A (en) * | 2012-08-31 | 2012-11-28 | 济钢集团有限公司 | 800 MPa economic corrosion-resistance and high-strength steel plate |
| CN103667912A (en) * | 2013-12-30 | 2014-03-26 | 莱芜钢铁集团有限公司 | Low-alloy steel plate and heat treatment method for steel plate |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107287506A (en) | 2017-10-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103352167B (en) | A kind of low yield strength ratio high strength bridge steel plate and manufacture method thereof | |
| CN101363101B (en) | Large thickness quenched high strength steel and production method thereof | |
| CN107287506B (en) | 650 MPa-level medium-temperature medium-pressure boiler steel plate and production method thereof | |
| CN103194687B (en) | Low-alloy high-strength cast steel for low temperature and preparation method thereof | |
| WO2023000584A1 (en) | 1000 mpa-grade quenched and tempered hydroelectric steel plate and production method therefor | |
| CN101928885B (en) | Hydrothion corrosion resistant pipe steel and production method thereof | |
| CN102560284B (en) | High-strength high-toughness X100 pipeline steel hot-rolled steel strip and manufacturing method thereof | |
| CN111607748A (en) | High-flatness large-thickness lamellar tearing resistant 780CF-Z35 hydroelectric steel and manufacturing method thereof | |
| CN106811700B (en) | Thick acid-resistant X60MS hot-rolled coil and manufacturing method thereof | |
| CN102011047A (en) | Production method of steel plate for pressure vessel with low cost and high performance | |
| CN102367540B (en) | Deep sea pipeline steel produced based on steckel mill and preparation method thereof | |
| CN102732782A (en) | Production method of steel plate for heavy-gauge pressure vessel | |
| CN101928876A (en) | TRIP/TWIP high-strength plastic automobile steel with excellent processability and preparation method thereof | |
| CN102691018A (en) | Low-compression ratio super-strength steel plate for ocean engineering and manufacturing method thereof | |
| CN110983187A (en) | Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof | |
| CN105177446A (en) | Steel for 600-DEG C medium-temperature nuclear power pressure vessel and manufacturing method thereof | |
| CN103205643B (en) | A kind of high hardness wear-resisting steel pipe and manufacture method thereof | |
| CN107988548B (en) | X80 pipeline steel plate adapting to low-temperature exposed environment and production method thereof | |
| CN102400062B (en) | Low yield ratio and ultrahigh strength X130 pipeline steel | |
| CN102605246A (en) | Steel for low-strain-ageing sensitive welding structure and production method of steel | |
| CN102337458B (en) | Steel with tensile strength not lower than 1100MPa for engineering machinery and production method thereof | |
| CN103866199A (en) | Steel plate used for ocean energy equipment and preparation process of steel plate | |
| CN112048659B (en) | High-strength high-ductility steel plate and preparation method thereof | |
| CN112538595A (en) | Hot continuous rolled steel for 125 ksi-level oil well pipe, 125 ksi-level oil well pipe and preparation method | |
| CN114058960B (en) | High-strength high-toughness easy-welding nano steel with thickness of 25-60 mm and thickness of 1000MPa and preparation 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |