CN115094316A - Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof - Google Patents
Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof Download PDFInfo
- Publication number
- CN115094316A CN115094316A CN202210701919.8A CN202210701919A CN115094316A CN 115094316 A CN115094316 A CN 115094316A CN 202210701919 A CN202210701919 A CN 202210701919A CN 115094316 A CN115094316 A CN 115094316A
- Authority
- CN
- China
- Prior art keywords
- steel plate
- temperature
- rolling
- percent
- continuous casting
- 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.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/28—Normalising
-
- 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
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips 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
- C21D8/02—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
-
- 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
-
- 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
- C22C38/06—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
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
-
- 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
-
- 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
- C21D2211/009—Pearlite
-
- 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)
- 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 an extra-thick steel plate with excellent core low-temperature impact toughness and a manufacturing method thereof, belonging to the technical field of extra-thick plate production. The method comprises the steps of adding refined grain elements in the steelmaking process, adopting an ultra-thick continuous casting billet with the grain size of 450-475 mm, controlling the heating temperature and austenite grain size of the continuous casting billet, carrying out forced cooling on the continuous casting billet in the rough rolling and finish rolling processes to generate temperature difference between the surface and the core of the continuous casting billet, promoting rolling deformation to penetrate into the core of a steel plate, adopting weak water cooling to replace conventional air cooling after the steel plate is normalized and discharged out of a furnace, reducing phase change temperature, refining grains, carrying out tempering heat treatment to release stress and homogenize the structure. The extra-thick plate with the thickness of 170-200 mm produced by the method has good 1/4 and 1/2 heart position-60 ℃ impact energy, the heart tissue of the steel plate is uniformly refined, the flaw detection result meets the standard requirements of NB/T47013.3-2015 and TII level, and the comprehensive performance is excellent.
Description
Technical Field
The invention belongs to the technical field of production of extra-thick plates, and particularly relates to an extra-thick steel plate with excellent core low-temperature impact toughness and a manufacturing method thereof.
Background
The extra-thick plate is widely applied to a plurality of fields such as ships, pressure vessels, wind power and the like, and is an important component for manufacturing other large-scale structural members such as ocean platforms, boiler pressure vessels, high-rise buildings, wind power generation foundation rings and the like. Generally, a steel plate with the thickness of more than or equal to 60mm is called an extra thick plate, and for an extra thick plate with the thickness of more than 150mm, the traditional mode adopts a die-cast steel ingot for production, and the production cost is high due to large cutting loss and low yield. In order to reduce the production cost and improve the product competitiveness, in recent years, domestic main steel mills are continuously promoted to adopt continuous casting billets to produce extra-thick plates, but because the thickness of the continuous casting billets is limited, the rolling compression ratio is small, the rolling deformation is difficult to deepen, the core tissues of the extra-thick plates are thick, loose shrinkage cavities are difficult to heal, the impact properties of the core positions of the extra-thick plates 1/4 and 1/2 are unstable, particularly the low-temperature impact toughness is poor, and the defect is not qualified when high-grade flaw detection is carried out according to the energy standards of NB/T47013.3-2015I grade or TII grade and the like. The core performance problem of the extra-thick plate becomes an important bottleneck for development and production of the extra-thick plate at the present stage.
In comparison with document 1, in a method (CN 109013711 a) for improving the core quality and flaw detection qualification rate of an extra-thick plate, an instant cooling device is used to perform one-pass or multi-pass online cooling on a 300-400 mm continuous casting billet in a rolling gap, so as to achieve the purpose of improving the core quality of the extra-thick plate. The patent does not effectively control the heating process, rolling passes, rolling reduction, rolling speed and the like, the thickness of the produced low-temperature impact super-thick plate is only 100mm, meanwhile, the low-temperature impact super-thick plate can only reach the impact requirement of minus 20 ℃, and the flaw detection level can only reach the national standard level 2 requirement.
In comparison with document 2, a normalized high-toughness 150mm extra-thick steel sheet and a production method thereof (CN 104962814 a), a Q460 grade high-toughness extra-thick steel sheet was developed by controlled rolling and cooling and performing normalization treatment. The patent does not accurately control the rolling process and the heat treatment process such as rolling pass, rolling speed and the like due to insufficient compression ratio, the thickness specification of the related steel plate can only reach 150mm, the impact performance of the center part is unstable, and the flaw detection and the internal quality are difficult to ensure due to the fact that special process control is not carried out.
Disclosure of Invention
The invention aims to provide an ultra-thick steel plate with excellent core low-temperature impact toughness and a manufacturing method thereof, and aims to solve the problems in the prior art.
The invention is realized by the following technical scheme: an extra thick steel plate with excellent core low-temperature impact toughness is characterized in that: the super-thick plate comprises the following components in percentage by mass: c: 0.12 to 0.16 percent; si: 0.20-0.40%; mn: 1.40-1.60%; nb: 0.015-0.040%; ti: 0.008-0.025%; and (3) Alt: 0.020-0.050%; cu: 0.10-0.30%; ni: 0.15 to 0.40 percent; p: less than or equal to 0.012 percent; s: less than or equal to 0.003 percent; n: less than or equal to 0.0050 percent; o: less than or equal to 0.0040 percent; h: less than or equal to 0.0002 percent; the balance of Fe and inevitable impurities.
Further: the super-thick plate comprises the following components in percentage by mass: c: 0.13-0.14%; si: 0.25 to 0.27 percent; mn: 1.52-1.55%; nb: 0.021-0.025%; ti: 0.011-0.013%; and (3) Alt: 0.025-0.033%; cu: 0.15 to 0.17 percent; ni: 0.18 to 0.19 percent; p: less than or equal to 0.010 percent; s: less than or equal to 0.002 percent; n: less than or equal to 0.0038 percent; o: less than or equal to 0.0032 percent; h: less than or equal to 0.00014 percent; the balance of Fe and inevitable impurities.
The other technical scheme of the invention is as follows: a manufacturing method of an extra-thick steel plate with excellent core low-temperature impact toughness comprises the steps of continuous casting billet smelting, continuous casting billet heating, steel plate rolling, steel plate stacking slow cooling, steel plate normalizing and steel plate tempering, and is characterized in that:
1) smelting a continuous casting billet: the molten iron is subjected to pretreatment, desulfurization and slagging, and refining treatment by an LF furnace and an RH furnace, electromagnetic stirring and terminal heavy pressure are put into use in the continuous casting process, the molten iron is produced at a constant drawing speed of 0.45-0.60 m/min, the superheat degree is 15-30 ℃, extra-thick continuous casting billets with the thickness of 450-475 mm are adopted, and the continuous casting billets are stacked and slowly cooled;
2) heating a continuous casting blank: the cold charging of the continuous casting billet into a furnace, and the sectional heating of a walking beam type heating furnace, wherein the temperature of a first heating section is 900-1040 ℃, the temperature of a second heating section is 1020-1140 ℃, the temperature of a third heating section is 1130-1200 ℃, the temperature of a soaking section is 1150-1180 ℃, and the heating time of the continuous casting billet in the furnace is 500-650 min;
3) rolling a steel plate: rough rolling is carried out with two stages of rolling in a transverse rolling mode and a longitudinal rolling mode, the initial rolling temperature is 1040-1090 ℃, after the transverse rolling is finished, a water cooling device is started to carry out forced cooling, the surface temperature of the continuous casting billet is rapidly cooled to 830-870 ℃, the temperature difference is generated between the surface and the core of the continuous casting billet, the rolling deformation is promoted to penetrate into the core of a steel plate, the core is fully recrystallized to refine grains, after the water cooling, the longitudinal rolling is carried out, the longitudinal rolling adopts low-speed high-pressure rolling, the rolling reduction of a single-pass rolling is 35-70 mm, the total rolling reduction of the longitudinal rolling is 80-120 mm, and the rolling speed is controlled to be 0.80-1.50 m/s; a water spraying and cooling device is started at intervals of rolling passes to reduce the surface temperature of the steel plate and keep the temperature difference between the surface and the core, and the thickness of the intermediate blank after rough rolling is the thickness of the finished steel plate plus 50 mm-80 mm; starting a water cooling device to perform forced cooling in the intermediate billet temperature waiting process, rapidly cooling the surface temperature to 800-830 ℃, then performing finish rolling, starting a water spraying cooling device at intervals of finish rolling passes, controlling the finish rolling speed to be 1.00-2.00 m/s and the finish rolling temperature to be 810-840 ℃; carrying out water cooling on the rolled steel plate, wherein the water yield is 120-140 m/h, the number of water groups is 15-22 groups, the water cooling roller speed is 0.4-1.0 m/s, the steel plate returns red for more than 90s after water cooling, and the temperature of returning red is 650-690 ℃;
4) steel plate stacking and slow cooling: the stacking slow cooling temperature of the steel plate is 500-600 ℃, and the stacking slow cooling time is more than 72 h;
5) normalizing the steel plate: normalizing by using a continuous heat treatment furnace, wherein the first-stage heating temperature is 840 ℃, the second-stage heating temperature is 850 ℃, the third-stage heating temperature is 860 ℃, the fourth-stage heating temperature is 870 ℃, the fifth-stage heating temperature is 880 ℃, the sixth-to ninth-stage heating temperature is 890 ℃, and the total in-furnace time of the steel plate is as follows: (1.6-2.0) x the thickness of the steel plate min. Cooling the steel plate by weak water cooling after discharging, returning the steel plate to the red temperature of 620-650 ℃ after the weak water cooling, and then air cooling to room temperature;
6) tempering the steel plate: the tempering temperature is 550-580 ℃, and the total in-furnace tempering time is as follows: (2.5-3.5) multiplied by the thickness of the steel plate for min, and air-cooling to room temperature after tempering and discharging.
And further: the thickness of the super-thick plate is 170-200 mm.
Further: the metallographic structure of the extra-thick plate is ferrite plus pearlite, and the grain sizes of the 1/4-thick position and the 1/2-thick position are more than or equal to 7.5 grade.
The invention has the advantages that: according to the 170-200 mm extra-thick plate produced by the method, the impact values of 1/4 and 1/2 at the heart positions of-60 ℃ are more than or equal to 88J, the supercooling degree is increased in a phase change link, the phase change temperature is reduced, ferrite grains are refined, the spacing between pearlite layers is reduced, the grain size of the heart is refined to 7.5 grade, the defects of continuous casting blanks such as central porosity and shrinkage cavity are fully healed in the rolling process, and the flaw detection result meets the standard requirements of NB/T47013.3-2015 and TII grade.
Drawings
The microstructure of the example steel plate of fig. 1 at thickness 1/4 is shown.
The example of fig. 2 has a microstructure at 1/2 a thickness of the steel sheet.
Detailed Description
The invention discloses an extra-thick steel plate with excellent core low-temperature impact toughness, which comprises the following components in percentage by mass: c: 0.12 to 0.16 percent; si: 0.20 to 0.40 percent; mn: 1.40-1.60%; nb: 0.015-0.040%; ti: 0.008-0.025%; and (3) Alt: 0.020-0.050%; cu: 0.10-0.30%; ni: 0.15 to 0.40 percent; p: less than or equal to 0.012 percent; s: less than or equal to 0.003 percent; n: less than or equal to 0.0050 percent; o: less than or equal to 0.0040 percent; h: less than or equal to 0.0002 percent; the balance of Fe and inevitable impurities.
Preferably: the super-thick plate comprises the following components in percentage by mass: c: 0.13-0.14%; si: 0.25 to 0.27 percent; mn: 1.52-1.55%; nb: 0.021 to 0.025 percent; ti: 0.011-0.013%; and (3) Alt: 0.025-0.033%; cu: 0.15 to 0.17 percent; ni: 0.18 to 0.19 percent; p: less than or equal to 0.010 percent; s: less than or equal to 0.002 percent; n: less than or equal to 0.0038 percent; o: less than or equal to 0.0032 percent; h: less than or equal to 0.00014 percent; the balance of Fe and inevitable impurities.
The invention also discloses a manufacturing method of the super-thick steel plate with excellent core low-temperature impact toughness, which comprises the steps of continuous casting billet smelting, continuous casting billet heating, steel plate rolling, steel plate stacking slow cooling, steel plate normalizing and steel plate tempering, wherein the steps of:
1) smelting a continuous casting billet: the molten iron is subjected to pretreatment, desulfurization and slagging, and refining treatment by an LF furnace and an RH furnace, electromagnetic stirring and terminal heavy pressure are put into use in the continuous casting process, the molten iron is produced at a constant drawing speed of 0.45-0.60 m/min, the superheat degree is 15-30 ℃, extra-thick continuous casting billets with the thickness of 450-475 mm are adopted, and the continuous casting billets are stacked and slowly cooled;
2) heating a continuous casting blank: the cold charging of the continuous casting billet into a furnace, and the sectional heating of a walking beam type heating furnace, wherein the temperature of a first heating section is 900-1040 ℃, the temperature of a second heating section is 1020-1140 ℃, the temperature of a third heating section is 1130-1200 ℃, the temperature of a soaking section is 1150-1180 ℃, and the heating time of the continuous casting billet in the furnace is 500-650 min;
3) rolling a steel plate: roughly rolling in two stages of transverse and longitudinal rolling, wherein the initial rolling temperature is 1040-1090 ℃, after the transverse rolling is finished, a water cooling device is started for forced cooling, the surface temperature of the continuous casting billet is rapidly cooled to 830-870 ℃, so that the temperature difference is generated between the surface and the core of the continuous casting billet, the rolling deformation is promoted to penetrate into the core of a steel plate, the core is fully recrystallized and refined, after the water cooling, the longitudinal rolling is carried out, the longitudinal rolling adopts low-speed high-pressure rolling, the rolling reduction of single-pass rolling is 35-70 mm, the total rolling reduction of the longitudinal rolling is 80-120 mm, and the rolling speed is controlled at 0.80-1.50 m/s; spraying water cooling devices are started at intervals of rolling passes to reduce the surface temperature of the steel plate and keep the temperature difference between the surface and the core, and the thickness of the intermediate blank after rough rolling is +50 mm-80 mm of the thickness of the finished steel plate; starting a water cooling device to perform forced cooling in the intermediate billet temperature waiting process, rapidly cooling the surface temperature to 800-830 ℃, then performing finish rolling, starting a water spraying cooling device at intervals of finish rolling passes, controlling the finish rolling speed to be 1.00-2.00 m/s and the finish rolling temperature to be 810-840 ℃; carrying out water cooling on the rolled steel plate to reduce the phase transition temperature of the core part of the steel plate, refine ferrite grains and reduce the spacing between pearlite lamellae, carrying out 120-140 m/h water quantity, carrying out 15-22 groups of water groups, carrying out 0.4-1.0 m/s water cooling roller speed, carrying out more than 90s red return on the steel plate after water cooling, and carrying out 650-690 ℃ red return temperature;
4) steel plate stacking and slow cooling: the stacking slow cooling temperature of the steel plate is 500-600 ℃, and the stacking slow cooling time is more than 72 h;
5) normalizing the steel plate: normalizing by using a continuous heat treatment furnace, wherein the first-stage heating temperature is 840 ℃, the second-stage heating temperature is 850 ℃, the third-stage heating temperature is 860 ℃, the fourth-stage heating temperature is 870 ℃, the fifth-stage heating temperature is 880 ℃, the sixth-to ninth-stage heating temperature is 890 ℃, and the total in-furnace time of the steel plate is as follows: (1.6-2.0) x the thickness of the steel plate min. Cooling the steel plate by weak water cooling after discharging, returning the steel plate to the red temperature of 620-650 ℃ after the weak water cooling, and then air cooling to room temperature;
6) tempering the steel plate: the tempering temperature is 550-580 ℃, and the total in-furnace tempering time is as follows: (2.5-3.5) multiplied by the thickness of the steel plate for min, and air-cooling to room temperature after tempering and discharging.
Wherein: the thickness of the super-thick plate is 170-200 mm.
According to metallographic detection of the steel plate, as shown in fig. 1 and fig. 2, the metallographic structure of the super-thick steel plate is ferrite plus pearlite, the pearlite is precipitated along grain boundaries in a block shape, the grain size of the center part of the steel plate with the thickness of 1/2 reaches 7.5 grades, the ferrite is fine and uniform, defects such as center porosity, shrinkage cavity and the like are fully healed in the rolling process, and excellent low-temperature toughness of the center part is obtained.
The scheme of the invention is further illustrated below by means of specific examples:
and adopting an ultra-thick continuous casting billet with the thickness of 450-475 mm to complete the steps of continuous casting billet smelting, steel plate rolling, steel plate normalizing, steel plate tempering and the like.
This embodiment includes 3 specific examples, which are respectively represented by numbers 1, 2, and 3, and the specific embodiments are as follows:
the actual chemical composition of this example is shown in Table 1.
TABLE 1 chemical composition (wt%)
| Serial number | C | Si | Mn | P | S | Alt | Nb | Ti | Cu | Ni | H | O | N |
| 1 | 0.13 | 0.27 | 1.53 | 0.010 | 0.002 | 0.030 | 0.021 | 0.011 | 0.15 | 0.18 | 0.00013 | 0.0025 | 0.0035 |
| 2 | 0.14 | 0.26 | 1.52 | 0.010 | 0.001 | 0.025 | 0.025 | 0.013 | 0.17 | 0.19 | 0.00010 | 0.0032 | 0.0038 |
| 3 | 0.13 | 0.25 | 1.55 | 0.009 | 0.002 | 0.033 | 0.023 | 0.011 | 0.16 | 0.18 | 0.00014 | 0.0030 | 0.0032 |
The rolling and heat treatment process of the extra-thick plate comprises heating, rough rolling, finish rolling, controlled cooling, stacking slow cooling, normalizing, tempering and the like, wherein the technological parameters in the heating stage are as follows:
TABLE 2 heating Process parameters
| Serial number | First heating section temperature | Temperature of the second heating section | Temperature of the third heating section | Temperature of soaking zone | Heating time min |
| 1 | 927 | 1110 | 1180 | 1165 | 558 |
| 2 | 925 | 1105 | 1170 | 1160 | 565 |
| 3 | 930 | 1118 | 1175 | 1162 | 570 |
The technological parameters in the rough rolling stage are as follows:
TABLE 3 Rough rolling Process parameters
| Serial number | The start rolling temperature is DEG C | Water cooling device | Single-pass rolling reduction mm in longitudinal rolling | Longitudinal rolling pass | Longitudinal rolling starting temperature ℃ (slab surface) | Total reduction of longitudinal rolling mm | Rolling speed m/s |
| 1 | 1055 | Is opened | 47-45 | 2 | 840 | 92 | 1.20 |
| 2 | 1057 | Is opened | 48-46 | 2 | 838 | 94 | 1.15 |
| 3 | 1060 | Is opened | 49-45 | 2 | 845 | 94 | 1.20 |
The process parameters of the finish rolling stage are as follows:
TABLE 4 finish Rolling Process parameters
| Serial number | Thickness mm of waiting temperature | Water cooling device | Finish rolling start temperature ℃ (slab surface) | Finish rolling speed m/s | Finish rolling temperature of finish rolling |
| 1 | 230 | Is opened | 805 | 1.65 | 831 |
| 2 | 240 | Is opened | 809 | 1.65 | 835 |
| 3 | 260 | Is opened | 812 | 1.60 | 830 |
The technological parameters of water cooling and stacking of the steel plate are as follows:
TABLE 5 Water Cooling and Stacking Process parameters
| Serial number | Water yield m/h | Number of water groups | Roller speed m/s | Time of reddening s | Temperature of red return | Temperature of start of stacking | Stacking time h |
| 1 | 120 | 20 | 0.5 | 120 | 672 | 526 | 82 |
| 2 | 125 | 20 | 0.5 | 120 | 679 | 535 | 82 |
| 3 | 130 | 20 | 0.5 | 120 | 685 | 540 | 85 |
Heating in a step-type temperature heating mode in each heating section in the normalizing process, wherein the first-section heating temperature is 840 ℃, the second-section heating temperature is 850 ℃, the third-section heating temperature is 860 ℃, the fourth-section heating temperature is 870 ℃, the fifth-section heating temperature is 880 ℃, the sixth-section to ninth-section heating temperature is 890 ℃, the steel plate is cooled by weak water cooling after being discharged from the furnace, then is cooled to room temperature by air, and then is subjected to tempering heat treatment. The normalizing and tempering process parameters are as follows:
TABLE 6 normalizing and tempering Process parameters
| Serial number | Normalizing total on-furnace time min | Temperature of weak water-cooling re-reddening | Tempering temperature DEG C | Tempering in furnace time min |
| 1 | 306 | 635 | 570 | 510 |
| 2 | 324 | 638 | 570 | 540 |
| 3 | 360 | 640 | 570 | 600 |
Through inspection, the comprehensive performance of the 1/4-thick and 1/2-heart-part positions of the steel plate is good, wherein ReH (yield strength) is more than or equal to 305MPa and less than or equal to 325MPa, Rm (tensile strength) is more than or equal to 490MPa and less than or equal to 512MPa, A (elongation after fracture) is more than or equal to 23.0%, the impact value at-60 ℃ of the 1/2-heart-part position is more than or equal to 88J, the grain size of the 1/4-position is 8.0 grade, the grain size of the 1/2-heart-part position is 7.5 grade, the metallographic structure is ferrite plus pearlite, the heart-part structure is uniformly refined, the flaw detection result meets the standard requirements of NB/T47013.3-2015 and TII grade, and the specific inspection result is as follows:
table 7 test results
The above examples are merely illustrative of the best mode of carrying out the invention and do not limit the scope of the invention in any way.
Claims (5)
1. An extra thick steel plate with excellent core low-temperature impact toughness is characterized in that: the super-thick plate comprises the following components in percentage by mass: c: 0.12 to 0.16 percent; si: 0.20 to 0.40 percent; mn: 1.40 to 1.60 percent; nb: 0.015-0.040%; ti: 0.008-0.025%; and (3) Alt: 0.020-0.050%; cu: 0.10-0.30%; ni: 0.15 to 0.40 percent; p: less than or equal to 0.012 percent; s: less than or equal to 0.003 percent; n: less than or equal to 0.0050 percent; o: less than or equal to 0.0040 percent; h: less than or equal to 0.0002 percent; the balance of Fe and inevitable impurities.
2. The super thick steel plate having excellent low-temperature impact toughness at core as claimed in claim 1, wherein: the super-thick plate comprises the following components in percentage by mass: c: 0.13-0.14%; si: 0.25 to 0.27 percent; mn: 1.52-1.55%; nb: 0.021 to 0.025 percent; ti: 0.011-0.013%; and (3) Alt: 0.025-0.033%; cu: 0.15-0.17%; ni: 0.18 to 0.19 percent; p: less than or equal to 0.010 percent; s: less than or equal to 0.002 percent; n: less than or equal to 0.0038 percent; o: less than or equal to 0.0032 percent; h: less than or equal to 0.00014 percent; the balance of Fe and inevitable impurities.
3. A manufacturing method of an ultra-thick steel plate with excellent core low-temperature impact toughness comprises the steps of continuous casting billet smelting, continuous casting billet heating, steel plate rolling, steel plate stacking slow cooling, steel plate normalizing and steel plate tempering, and is characterized in that:
1) smelting a continuous casting billet: the molten iron is subjected to pretreatment, desulfurization and slagging, and refining treatment by an LF furnace and an RH furnace, electromagnetic stirring and terminal heavy pressure are put into use in the continuous casting process, the molten iron is produced at a constant drawing speed of 0.45-0.60 m/min, the superheat degree is 15-30 ℃, extra-thick continuous casting billets with the thickness of 450-475 mm are adopted, and the continuous casting billets are stacked and slowly cooled;
2) heating a continuous casting blank: the cold charging of the continuous casting billet into a furnace, and the sectional heating of a walking beam type heating furnace, wherein the temperature of a first heating section is 900-1040 ℃, the temperature of a second heating section is 1020-1140 ℃, the temperature of a third heating section is 1130-1200 ℃, the temperature of a soaking section is 1150-1180 ℃, and the heating time of the continuous casting billet in the furnace is 500-650 min;
3) rolling a steel plate: roughly rolling in two stages of transverse and longitudinal rolling, wherein the initial rolling temperature is 1040-1090 ℃, after the transverse rolling is finished, a water cooling device is started for forced cooling, the surface temperature of the continuous casting billet is rapidly cooled to 830-870 ℃, so that the temperature difference is generated between the surface and the core of the continuous casting billet, the rolling deformation is promoted to penetrate into the core of a steel plate, the core is fully recrystallized and refined, after the water cooling, the longitudinal rolling is carried out, the longitudinal rolling adopts low-speed high-pressure rolling, the rolling reduction of single-pass rolling is 35-70 mm, the total rolling reduction of the longitudinal rolling is 80-120 mm, and the rolling speed is controlled at 0.80-1.50 m/s; a water spraying and cooling device is started at intervals of rolling passes to reduce the surface temperature of the steel plate and keep the temperature difference between the surface and the core, and the thickness of the intermediate blank after rough rolling is the thickness of the finished steel plate plus 50 mm-80 mm; starting a water cooling device to perform forced cooling in the intermediate billet temperature waiting process, rapidly cooling the surface temperature to 800-830 ℃, then performing finish rolling, starting a water spraying cooling device at intervals of finish rolling passes, controlling the finish rolling speed to be 1.00-2.00 m/s and the finish rolling temperature to be 810-840 ℃; carrying out water cooling on the rolled steel plate, wherein the water yield is 120-140 m/h, the number of water groups is 15-22 groups, the water cooling roller speed is 0.4-1.0 m/s, the steel plate returns red for more than 90s after water cooling, and the temperature of returning red is 650-690 ℃;
4) and (3) slow cooling of steel plate stacking: the stacking slow cooling temperature of the steel plate is 500-600 ℃, and the stacking slow cooling time is more than 72 h;
5) normalizing the steel plate: normalizing by using a continuous heat treatment furnace, wherein the first-stage heating temperature is 840 ℃, the second-stage heating temperature is 850 ℃, the third-stage heating temperature is 860 ℃, the fourth-stage heating temperature is 870 ℃, the fifth-stage heating temperature is 880 ℃, the sixth-to ninth-stage heating temperature is 890 ℃, and the total time minutes of the steel plate in the furnace is as follows: (1.6-2.0) x the thickness of the steel plate by millimeters; cooling the steel plate by weak water cooling after discharging, returning the steel plate to the red temperature of 620-650 ℃ after the weak water cooling, and then air cooling to room temperature;
6) tempering the steel plate: the tempering temperature is 550-580 ℃, and the total tempering time in the furnace is as follows: (2.5-3.5) x the thickness of the steel plate by mm, tempering, and then air-cooling to room temperature.
4. The method of manufacturing a super thick steel plate having excellent low-temperature impact toughness at the core according to claim 3, wherein: the thickness of the super-thick plate is 170-200 mm.
5. The method of manufacturing a super thick steel plate having excellent low-temperature impact toughness at the core according to claim 3, wherein: the metallographic structure of the extra-thick plate is ferrite plus pearlite, and the grain sizes of the 1/4-thick position and the 1/2-thick position are more than or equal to 7.5 grade.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210701919.8A CN115094316B (en) | 2022-06-21 | 2022-06-21 | Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210701919.8A CN115094316B (en) | 2022-06-21 | 2022-06-21 | Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115094316A true CN115094316A (en) | 2022-09-23 |
| CN115094316B CN115094316B (en) | 2023-06-20 |
Family
ID=83292175
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210701919.8A Active CN115094316B (en) | 2022-06-21 | 2022-06-21 | Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115094316B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000355728A (en) * | 1999-06-11 | 2000-12-26 | Sumitomo Metal Ind Ltd | Heat treated high strength steel and continuously cast slab for the steel |
| CN102747285A (en) * | 2012-07-11 | 2012-10-24 | 秦皇岛首秦金属材料有限公司 | Ultrathick steel plate for ships and ocean platforms and production method thereof |
| CN103397251A (en) * | 2013-08-05 | 2013-11-20 | 武汉钢铁(集团)公司 | 150-190 mm thick bridge steel produced by continuous casting slab and technology thereof |
| JP2016089188A (en) * | 2014-10-30 | 2016-05-23 | Ｊｆｅスチール株式会社 | Thick steel plate and method of producing the same |
| CN106086642A (en) * | 2016-06-23 | 2016-11-09 | 江阴兴澄特种钢铁有限公司 | A kind of 200mm thickness resistance against hydrogen cracking steel plate of pressure vessel and manufacture method thereof |
| CN107557690A (en) * | 2016-06-30 | 2018-01-09 | 鞍钢股份有限公司 | The super-thick steel plate and its manufacture method of a kind of low temperature resistant and anti-lamellar tearing |
| CN108914008A (en) * | 2018-08-10 | 2018-11-30 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of economical high-ductility 360MPa level structure steel plate and its manufacturing method |
| CN110184528A (en) * | 2018-06-11 | 2019-08-30 | 江阴兴澄特种钢铁有限公司 | With the Q345R steel plate and its manufacturing method of excellent properties under the conditions of a kind of High Temperature Simulation post weld heat treatment |
| CN111363973A (en) * | 2020-03-11 | 2020-07-03 | 江阴兴澄特种钢铁有限公司 | Super-thick container steel plate with excellent core low-temperature impact toughness and manufacturing method thereof |
| US20210062285A1 (en) * | 2017-12-26 | 2021-03-04 | Posco | Steel Material Showing Excellent Hydrogen-Induced Cracking Resistance and Method for Preparing Same |
| US20220025474A1 (en) * | 2020-12-22 | 2022-01-27 | Northeastern University | 785 MPa LEVEL EXTRA-THICK QUENCHED AND TEMPERED RACK STEEL PLATE FOR OFFSHORE PLATFORMS AND PREPARATION METHOD THEREFOR |
-
2022
- 2022-06-21 CN CN202210701919.8A patent/CN115094316B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000355728A (en) * | 1999-06-11 | 2000-12-26 | Sumitomo Metal Ind Ltd | Heat treated high strength steel and continuously cast slab for the steel |
| CN102747285A (en) * | 2012-07-11 | 2012-10-24 | 秦皇岛首秦金属材料有限公司 | Ultrathick steel plate for ships and ocean platforms and production method thereof |
| CN103397251A (en) * | 2013-08-05 | 2013-11-20 | 武汉钢铁(集团)公司 | 150-190 mm thick bridge steel produced by continuous casting slab and technology thereof |
| JP2016089188A (en) * | 2014-10-30 | 2016-05-23 | Ｊｆｅスチール株式会社 | Thick steel plate and method of producing the same |
| CN106086642A (en) * | 2016-06-23 | 2016-11-09 | 江阴兴澄特种钢铁有限公司 | A kind of 200mm thickness resistance against hydrogen cracking steel plate of pressure vessel and manufacture method thereof |
| CN107557690A (en) * | 2016-06-30 | 2018-01-09 | 鞍钢股份有限公司 | The super-thick steel plate and its manufacture method of a kind of low temperature resistant and anti-lamellar tearing |
| US20210062285A1 (en) * | 2017-12-26 | 2021-03-04 | Posco | Steel Material Showing Excellent Hydrogen-Induced Cracking Resistance and Method for Preparing Same |
| CN110184528A (en) * | 2018-06-11 | 2019-08-30 | 江阴兴澄特种钢铁有限公司 | With the Q345R steel plate and its manufacturing method of excellent properties under the conditions of a kind of High Temperature Simulation post weld heat treatment |
| CN108914008A (en) * | 2018-08-10 | 2018-11-30 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of economical high-ductility 360MPa level structure steel plate and its manufacturing method |
| CN111363973A (en) * | 2020-03-11 | 2020-07-03 | 江阴兴澄特种钢铁有限公司 | Super-thick container steel plate with excellent core low-temperature impact toughness and manufacturing method thereof |
| US20220025474A1 (en) * | 2020-12-22 | 2022-01-27 | Northeastern University | 785 MPa LEVEL EXTRA-THICK QUENCHED AND TEMPERED RACK STEEL PLATE FOR OFFSHORE PLATFORMS AND PREPARATION METHOD THEREFOR |
Non-Patent Citations (1)
| Title |
|---|
| 范秋梅;付朝波;张永恒;王海珍;: "舵杆用Q345D钢热处理工艺对组织和性能的影响", 特殊钢 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115094316B (en) | 2023-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112981235B (en) | Hardened and tempered steel plate with yield strength of 420MPa grade for building structure and production method thereof | |
| CN101928876B (en) | TRIP/TWIP high strength plastic automotive steel with excellent processability and preparation method thereof | |
| CN111424219B (en) | Method for manufacturing gear shaft steel capable of being directly subjected to cold forging | |
| JP2020500108A (en) | Gear rack steel plate having a maximum thickness of 177.8 mm manufactured by continuous casting billet and method for manufacturing the same | |
| CN110438414A (en) | A method of eliminating ultra-wide ferritic stainless steel surface crack of plate | |
| CN110453157A (en) | A kind of manufacturing method of low yield strength ratio thin gauge pipe line steel | |
| CN109097699A (en) | A kind of 900MPa grades of hot rolling automotive frame steel and its manufacturing method | |
| CN106480368A (en) | One kind wards off rear high-strength hot rolled steel plate for counter enameling and its manufacture method | |
| CN111155028A (en) | Steel plate for normalized DH36 wind power and preparation method thereof | |
| WO2024027526A1 (en) | Extra-thick q500qe bridge steel plate and production method therefor | |
| CN110952023B (en) | Rare earth treated high-toughness 1100 MPa-grade steel plate and preparation method thereof | |
| CN111979499A (en) | Production method of low-cost Q460C thick steel plate | |
| CN114941068B (en) | Preparation method of rare earth microalloyed high-toughness 960 MPa-level ultrahigh-strength steel | |
| CN115558851A (en) | Hot rolled steel plate for 370 MPa-level engineering structure and manufacturing method thereof | |
| CN115094316B (en) | Super-thick steel plate with excellent core low-temperature impact toughness and manufacturing method thereof | |
| CN115572912A (en) | Method for controlling cooling uniformity of steel plate for economic 460 MPa-level engineering structure | |
| CN111979482B (en) | CrMn spring steel bloom and one-step-firing material preparation method thereof | |
| CN109047692A (en) | A kind of ultra-thin size high-tensile steel plate that can be used under the conditions of -60 DEG C and its manufacturing method | |
| CN115637373A (en) | Preparation method of hot-rolled wire rod for prestressed concrete steel bar | |
| CN103725989A (en) | Tempered-state hot-rolled X70 thick flat plate and manufacturing method thereof | |
| CN112496216A (en) | Forging production process of 30Cr15MoN high-nitrogen martensitic stainless steel bar | |
| CN102409252A (en) | Ultrahigh-strength cold-rolled steel plate and manufacturing method thereof | |
| CN110055466A (en) | The preparation method of hot rolling high-strength medium managese steel of the strength and ductility product greater than 30GPa% | |
| CN114892073B (en) | Steel plate suitable for cold spinning and manufacturing method thereof | |
| CN104988394B (en) | A kind of quenched S460G1+Q structural steel and manufacture 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 |