CN115896622A - 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness - Google Patents
800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness Download PDFInfo
- Publication number
- CN115896622A CN115896622A CN202211461145.2A CN202211461145A CN115896622A CN 115896622 A CN115896622 A CN 115896622A CN 202211461145 A CN202211461145 A CN 202211461145A CN 115896622 A CN115896622 A CN 115896622A
- Authority
- CN
- China
- Prior art keywords
- equal
- percent
- welding
- steel plate
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 65
- 239000010959 steel Substances 0.000 title claims abstract description 65
- 238000003466 welding Methods 0.000 title claims abstract description 35
- 239000000126 substance Substances 0.000 claims abstract description 17
- 239000012535 impurity Substances 0.000 claims abstract description 15
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 12
- 238000000034 method Methods 0.000 claims description 44
- 238000005096 rolling process Methods 0.000 claims description 42
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 37
- 230000008569 process Effects 0.000 claims description 30
- 238000001816 cooling Methods 0.000 claims description 27
- 238000010438 heat treatment Methods 0.000 claims description 18
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- 238000007664 blowing Methods 0.000 claims description 16
- 239000002893 slag Substances 0.000 claims description 15
- 229910052742 iron Inorganic materials 0.000 claims description 13
- 238000003723 Smelting Methods 0.000 claims description 12
- 238000007670 refining Methods 0.000 claims description 12
- 238000006477 desulfuration reaction Methods 0.000 claims description 11
- 230000023556 desulfurization Effects 0.000 claims description 11
- 238000009749 continuous casting Methods 0.000 claims description 10
- 230000009467 reduction Effects 0.000 claims description 10
- 238000009849 vacuum degassing Methods 0.000 claims description 10
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 8
- 229910052786 argon Inorganic materials 0.000 claims description 8
- 229910052791 calcium Inorganic materials 0.000 claims description 8
- 239000011575 calcium Substances 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 8
- 238000007872 degassing Methods 0.000 claims description 7
- 238000010791 quenching Methods 0.000 claims description 7
- 230000000171 quenching effect Effects 0.000 claims description 7
- 238000005496 tempering Methods 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 238000004321 preservation Methods 0.000 claims description 6
- 238000003756 stirring Methods 0.000 claims description 5
- 238000009489 vacuum treatment Methods 0.000 claims description 5
- 238000007667 floating Methods 0.000 claims description 4
- 238000010079 rubber tapping Methods 0.000 claims description 4
- 230000035945 sensitivity Effects 0.000 claims description 4
- 238000002791 soaking Methods 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 238000003825 pressing Methods 0.000 claims description 2
- 238000009847 ladle furnace Methods 0.000 description 11
- 239000000463 material Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- FBPFZTCFMRRESA-JGWLITMVSA-N D-glucitol Chemical compound OC[C@H](O)[C@@H](O)[C@H](O)[C@H](O)CO FBPFZTCFMRRESA-JGWLITMVSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000005452 bending Methods 0.000 description 3
- 238000001953 recrystallisation Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 229910001563 bainite Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000008520 organization Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 229910001309 Ferromolybdenum Inorganic materials 0.000 description 1
- 229910000592 Ferroniobium Inorganic materials 0.000 description 1
- 241000124879 Grus leucogeranus Species 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
Classifications
-
- 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
- Heat Treatment Of Steel (AREA)
Abstract
The invention discloses an 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness, which comprises the following chemical components in percentage by mass: c:0.07% -0.085%, si:0.15% -0.35%, mn: 1.2-1.60%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, alt:0.020% -0.050%, nb: 0.035-0.050%, ti of 0.015-0.030%, V: 0.035-0.050%, cr is less than or equal to 0.55%, mo is less than or equal to 0.55%, ni is less than or equal to 1.0%, cu is less than or equal to 0.50%, and the balance is Fe and inevitable impurities. The 800 MPa-grade easy-welding hydroelectric steel plate provided by the invention has excellent low-temperature impact toughness.
Description
Technical Field
The invention belongs to the field of metallurgical materials, and particularly relates to an 800 MPa-level easy-welding hydroelectric steel plate with excellent low-temperature impact toughness.
Background
The steel material special for hydropower generally takes a medium plate product as a main material, the steel material for pressure steel pipes of domestic hydropower stations mainly adopts 3 strength grades of steel, namely 500MPa grade, 600MPa grade and 800MPa grade, the 500MPa grade and the 600MPa grade are main streams of the steel material for hydropower stations, the 800MPa grade steel material for hydropower stations is the steel plate with the highest strength grade in the field of the steel material for hydropower stations in China, is applied to Jinshajiang white crane beach hydropower stations, wudongde hydropower stations, hebeifengning, jilin Donghua hydropower stations, huihao super pumped storage power stations and the like in batches, belongs to a typical product with high technical content and high added value, and has extremely strict requirements on indexes such as chemical components, mechanical properties, welding properties, thickness direction properties, transverse and longitudinal property stability, flaw detection and the like of the steel plate. The method is mainly used for manufacturing pressure pipelines, ribbed plates, branch pipes, volutes and the like of large hydropower stations, and has high requirements on strength, low-temperature toughness and welding performance of steel plates due to poor service environment.
Hydroelectric power generation is used as clean energy, has the characteristics of reproducibility, no pollution, low operating cost, convenience in carrying out electric power peak regulation and the like, and is favorable for improving the resource utilization rate. Under the condition that the traditional energy is increasingly tense, all countries in the world have high priority to develop water and electricity and utilize water resources. More than 70 hydropower project projects are planned and constructed, and the projects are mainly distributed in the watersheds of Yalu Tibetan Bujiang, anjiang, jinshajiang, langlang, huanghe upstream, heilongjiang, yi Gong Cangbu, panlong Tibetan Bujiang, minjiang and the like. In recent years, with the increasing numerical values of installed capacity, water head and the like of a hydropower station, the steel plate for the hydropower station of 800MPa level is urgently developed, and has good market prospect.
Disclosure of Invention
Aiming at one or more problems in the prior art, the invention provides an 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness, which comprises the following chemical components in percentage by mass: c:0.07% -0.085%, si:0.15% -0.35%, mn: 1.2-1.60%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, alt:0.020% -0.050%, nb: 0.035-0.050% of Ti, 0.015-0.030% of Ti, V:0.035 to 0.050 percent, less than or equal to 0.55 percent of Cr, less than or equal to 0.55 percent of Mo, less than or equal to 1.0 percent of Ni, less than or equal to 0.50 percent of Cu, and the balance of Fe and inevitable impurities;
the production method of the 800 MPa-level easy-welding hydroelectric steel plate comprises the following processes: the method comprises the following steps of molten iron pretreatment, converter smelting, LF external refining, RH vacuum degassing, continuous casting, slab heating, rolling and cooling, and heat treatment; wherein:
in the molten iron pretreatment process, the S content is less than or equal to 0.005 percent after the molten iron is subjected to desulfurization pretreatment, and slag is removed after desulfurization;
in the process of converter smelting, LF external refining and RH vacuum degassing, a converter adopts single slag operation, and the alkalinity of final slag is controlled to be 3.0-3.5; the converter bottom blowing gas adopts a full-process argon blowing mode, and then is refined outside an LF furnace for further deoxidation, desulfurization, inclusion removal and component and temperature adjustment; degassing the molten steel in an RH vacuum degassing stage to promote floating of impurities, wherein RH circulation gas adopts a full-process argon blowing mode to ensure that pure degassing time is more than 5 minutes, vacuum treatment is carried out for 20 minutes, vacuum is re-broken to carry out calcium treatment, and after the calcium treatment is finished, soft blowing time is ensured to be more than or equal to 10 minutes;
in the continuous casting process, electromagnetic stirring and light pressing are adopted, and the drawing speed is controlled to be 0.80-1.2m/min;
in the slab heating process, the on-furnace time and the out-furnace temperature of the slab are controlled, the on-furnace time is 250-320min, the soaking time is 30-60min, and the out-furnace temperature is 1220 +/-20 ℃;
in the rolling and cooling process, the rough rolling adopts single pass, the relative reduction rate of at least 2 passes is more than 14 percent, and the final temperature of the rough rolling is more than or equal to 1050 ℃; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the relative reduction rate of at least 2 passes is more than 14 percent, and the final rolling temperature of finish rolling is 820-850 ℃; laminar flow cooling equipment is adopted for cooling, a secondary system self-learning calculation result is adopted in a cooling mode, and the final cooling temperature is 630-680 ℃;
in the heat treatment process, a quenching and tempering process is adopted, the quenching temperature is 900-920 ℃, and the heat preservation time is 10-20 min; the tempering temperature is 600-650 ℃, and the heat preservation time is 20-40 min.
In some embodiments, the 800MPa grade easy-welding hydroelectric steel plate has the following chemical components in percentage by mass: c:0.074%, si:0.22%, mn:1.30%, P:0.011%, S:0.002%, alt:0.046%, nb:0.040%, ti 0.022%, V:0.047%, cr:0.42%, mo:0.35%, ni:0.55%, cu:0.21 percent, and the balance of Fe and inevitable impurities.
In some embodiments, the 800MPa grade easy-welding hydroelectric steel plate has the following chemical components in percentage by mass: c:0.076%, si:0.21%, mn:1.29%, P:0.013%, S:0.003%, alt:0.042%, nb:0.041%, ti:0.019%, V:0.045%, cr:0.44%, mo:0.37%, ni:0.57%, cu:0.23 percent, and the balance of Fe and inevitable impurities.
In some embodiments, the 800MPa grade easy-welding hydroelectric steel plate has the following chemical components in percentage by mass: c:0.079%, si:0.21%, mn:1.35%, P:0.011%, S:0.001%, alt:0.040%, nb:0.046%, ti of 0.020%, V:0.046%, cr:0.43%, mo:0.40%, ni:0.60%, cu:0.21 percent, and the balance of Fe and inevitable impurities.
In some embodiments, the 800MPa grade easy-welding hydroelectric steel plate has the following chemical components in percentage by mass: c:0.080%, si:0.19%, mn:1.41%, P:0.010%, S:0.004%, alt:0.040%, nb:0.048%, ti 0.025%, V:0.048%, cr:0.46%, mo:0.41%, ni:0.80%, cu:0.25 percent, and the balance of Fe and inevitable impurities.
In some embodiments, the transverse impact energy of the 800 MPa-grade easy-to-weld hydroelectric steel plate at-40 ℃ is more than or equal to 185J, the yield strength is more than or equal to 756MPa, the tensile strength is more than or equal to 806MPa, the elongation A is more than or equal to 16.2%, and the weld crack sensitivity coefficient Pcm:0.22 to 0.24 percent.
In some embodiments, the thickness of the steel plate for the 800MPa grade easy-welding hydroelectric steel plate is 12.0mm-90.0mm.
Based on the technical scheme, the steel plate for the 800 MPa-grade easy-welding hydroelectric steel, which is provided by the technical scheme and has high yield ratio and excellent low-temperature impact toughness, has high steel cleanliness, fine and uniform tissue (the microstructure is tempered sorbite or tempered sorbite and tempered bainite), excellent low-temperature impact toughness (the transverse impact energy at the temperature of minus 40 ℃ is more than or equal to 185J), cold bending performance and welding performance (the carbon equivalent Ceq is 0.49-0.54%, and the welding crack sensitivity coefficient Pcm is 0.22-0.24%) by optimally designing chemical components and contents thereof and optimizing the production process, so that the steel plate for the 800 MPa-grade easy-welding hydroelectric steel, which is provided by the technical scheme, is more suitable for being in service under severe environmental conditions and is beneficial to the engineering construction of hydroelectric projects.
Drawings
FIG. 1 is a scanning electron micrograph of an 800MPa grade weldable steel plate for hydroelectric applications, produced in example 2.
Detailed Description
The invention aims to provide an 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness, cold bending property and welding property, and a production method of the steel plate.
In a first aspect, the 800 MPa-grade easy-welding hydroelectric steel plate comprises the following chemical components in percentage by mass: c:0.07% -0.085%, si:0.15% -0.35%, mn: 1.2-1.60%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, alt:0.020% -0.050%, nb: 0.035-0.050%, ti of 0.015-0.030%, V: 0.035-0.050%, cr is less than or equal to 0.55%, mo is less than or equal to 0.55%, ni is less than or equal to 1.0%, cu is less than or equal to 0.50%, and the balance is Fe and inevitable impurities.
In some embodiments, the transverse impact energy of the 800 MPa-grade steel plate for the easy-welding hydroelectric power at-40 ℃ is more than or equal to 185J, the yield strength is more than or equal to 756MPa, the tensile strength is more than or equal to 806MPa, the elongation A is more than or equal to 16.2%, and the welding crack sensitivity coefficient Pcm:0.22 to 0.24 percent.
In a second aspect, the production method of the 800 MPa-grade easy-welding hydroelectric steel plate comprises the following processes: the method comprises the following steps of molten iron pretreatment, converter smelting, LF external refining, RH vacuum degassing, continuous casting, slab heating, rolling and cooling, and heat treatment, wherein the hot iron pretreatment, converter smelting, LF external refining, RH vacuum degassing, continuous casting (electromagnetic stirring and light pressure), slab heating, descaling, rough rolling, finish rolling, laminar cooling, straightening, shot blasting, quenching, tempering, cold straightening and ultrasonic flaw detection are specifically carried out; wherein:
in the molten iron pretreatment process, the S content is less than or equal to 0.005 percent after the molten iron is subjected to desulfurization pretreatment, and slag is removed after desulfurization, so that less slag is carried in the molten iron;
in the process of converter smelting, LF external refining and RH vacuum degassing, a converter adopts single slag operation, high-quality active lime is used, the alkalinity of final slag is controlled to be 3.0-3.5, and self-produced high-quality scrap steel is used to reduce S brought by the scrap steel; the converter bottom blowing gas adopts a full-process argon blowing mode, and then is refined outside an LF furnace for further deoxidation, desulfurization, inclusion removal and component and temperature adjustment; degassing the molten steel in an RH vacuum degassing stage to promote floating of impurities, wherein RH circulation gas adopts a full-process argon blowing mode to ensure that pure degassing time is more than 5 minutes, vacuum treatment is carried out for 20 minutes, vacuum is re-broken to carry out calcium treatment, and after the calcium treatment is finished, soft blowing time is ensured to be more than or equal to 10 minutes;
in the continuous casting process, electromagnetic stirring and soft reduction are adopted, the pulling speed is controlled to be 0.80-1.2m/min, and the quality of a casting blank is ensured;
in the slab heating process, the on-furnace time and the out-furnace temperature of the slab are controlled, the on-furnace time is 250-320min, the soaking time is 30-60min, and the out-furnace temperature is 1220 +/-20 ℃;
in the rolling and cooling process, the rough rolling is carried out in a single pass according to different product thicknesses, the relative reduction rate of at least 2 passes is more than 14 percent, the final rolling temperature of the rough rolling is more than or equal to 1050 ℃, the rolling in a recrystallization zone is ensured, and austenite grains are fully refined; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the relative reduction rate of at least 2 passes is more than 14%, the final rolling temperature of finish rolling is 820-850 ℃, the rolling in a non-recrystallization area is ensured, and organization and energy preparation is carried out for subsequent phase change; laminar flow cooling equipment is adopted for cooling, a secondary system self-learning calculation result is adopted in a cooling mode, and the final cooling temperature is 630-680 ℃;
in the heat treatment process, a quenching and tempering process is adopted, the quenching temperature is 900-920 ℃, and the heat preservation time is 10-20 min; the tempering temperature is 600-650 ℃, and the heat preservation time is 20-40 min.
The present invention will be described in detail below with reference to specific examples, which are intended to facilitate understanding of the present invention and are not intended to limit the present invention.
Example 1:
(1) Firstly, molten iron is subjected to desulfurization pretreatment, slag must be removed after desulfurization, the purity of the desulfurized molten iron is ensured, and the S content is less than or equal to 0.005 percent after pretreatment.
(2) And then, smelting in a converter, wherein the converter adopts single slag operation, high-quality active lime is used, the alkalinity of final slag is controlled to be 3.0-3.5, and self-produced high-quality scrap steel is used to reduce S brought by the scrap steel. And (3) adopting a full-process argon blowing mode for converter bottom blowing gas, carrying out LF (ladle furnace) external refining on the molten steel after converter smelting, wherein the refining in-place temperature is more than or equal to 1570 ℃, ensuring the formation time of white slag by LF refining, and adding ferrocolumbium, ferrochromium, ferromolybdenum and the like after white slag to adjust to target components. And performing RH vacuum treatment on the molten steel after LF external refining, wherein the RH refining stage mainly degasses the molten steel and promotes inclusion floating, RH circulation gas adopts a full-process argon blowing mode to ensure that pure degassing time is more than 5 minutes, vacuum treatment is performed after 20 minutes, vacuum is re-broken to perform calcium treatment, and after the calcium treatment is finished, soft blowing time is ensured to be more than or equal to 10 minutes.
(3) The slab continuous casting is carried out according to the smelting chemical components shown in the table 1, the superheat degree is about 30 ℃, the drawing speed is controlled to be 0.80-1.2m/min, and the quality of the casting blank is ensured by adopting electromagnetic stirring and soft reduction. And then slab cleaning, slow cooling and continuous casting billet quality inspection are carried out. The process parameters shown in the following table 2 strictly control the furnace time and the tapping temperature of the slabs, wherein the furnace time is 253min, the soaking time is 30-60min, and the tapping temperature is 1222 ℃. And (3) carrying out high-pressure water descaling on the heated plate blank, and ensuring that the high-pressure water nozzle is normally opened without blockage, wherein the descaling pressure is not less than 20MPa.
(4) And (3) rolling the plate blank discharged from the furnace in a cooling process stage, wherein the rough rolling adopts a single pass, the relative reduction rate is controlled to be more than 14% by at least 2 passes, the final rolling temperature is 1062 ℃ according to the process parameters shown in the following table 2, then, the plate blank is subjected to temperature waiting to avoid rolling in a mixed crystal area, and the thickness of the temperature waiting is 3 times of the thickness of a finished product. And (3) finish rolling ensures rolling in a non-recrystallization area, the relative reduction rate of at least 2 passes is more than 14%, organization and energy preparation are carried out for subsequent phase change, the start rolling temperature of the finish rolling is 943 ℃, the finish rolling temperature of the finish rolling is 820 ℃, and the thickness of a finished product is 12.0mm. And then, carrying out laminar cooling, and adopting a secondary system self-learning calculation result in a cooling mode, wherein the final cooling temperature is 680 ℃.
(5) The steel plate after controlled rolling and controlled cooling is quenched and tempered according to the process conditions shown in the following table 3, and finally the surface quality and mechanical properties of the product are detected as shown in the following table 4.
Examples 2 to 4
Examples 2-4 steel plates for easy-to-weld hydroelectric power of 800MPa grade were produced according to the procedure of example 1, except that: (1) The smelting chemical components for performing the slab continuous casting process are different in content, and are specifically shown in the following table 1; (2) The parameters of the slab heating, rolling and cooling, and heat treatment processes are different, and are specifically shown in tables 2 and 3 below. The results of mechanical property tests on the 800MPa grade steel plates for easy-welding hydroelectric power, which are finally produced in examples 2-4, are shown in table 4 below. The metallographic structure of the steel sheet produced in example 2 was analyzed by a scanning electron microscope, and the result is shown in fig. 1, which indicates that the microstructure mainly includes tempered sorbite or tempered sorbite + tempered bainite.
Comparative example 1
Comparative example 1 an 800MPa grade easy-to-weld hydroelectric steel plate was produced according to the procedure of example 4, except that: (1) The parameters of the cooling, and heat treatment processes are different, and are specifically shown in tables 2 and 3 below. The results of mechanical property tests on the 800MPa grade easy-to-weld hydroelectric steel plate finally produced in comparative example 1 are shown in table 4 below.
Table 1: chemical composition (wt%) of smelting
Table 2: heating, rolling and cooling process parameters
Table 3: parameters of heat treatment process
Table 4: mechanical property of product
From the above tables 1 to 4, it can be seen that the steel plates for the 800 MPa-grade easy-to-weld hydroelectric steel plates produced in the examples 1 to 4 have high yield ratio, excellent low-temperature impact toughness, excellent cold bending property and excellent welding property, and the mechanical properties of the steel plates meet the following requirements: the yield strength is more than or equal to 756MPa, the tensile strength is more than or equal to 806MPa, the elongation A is more than or equal to 15.0 percent, the transverse impact energy at minus 40 ℃ meets more than or equal to 185J (preferably more than or equal to 196J), and the carbon equivalent Ceq:0.49% -0.54%, weld crack susceptibility Pcm: 0.22-0.24%, therefore, the 800 MPa-grade easy-welding hydroelectric steel plate provided by the invention is more suitable for being used under severe environmental conditions, and is beneficial to the construction of hydroelectric project engineering. In contrast, the steel sheet produced in comparative example 1 had relatively low-temperature impact toughness.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. An 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness comprises the following chemical components in percentage by mass: c:0.07% -0.085%, si:0.15% -0.35%, mn: 1.2-1.60%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, alt:0.020% -0.050%, nb: 0.035-0.050%, ti of 0.015-0.030%, V:0.035 to 0.050 percent, less than or equal to 0.55 percent of Cr, less than or equal to 0.55 percent of Mo, less than or equal to 1.0 percent of Ni, less than or equal to 0.50 percent of Cu, and the balance of Fe and inevitable impurities;
the production method of the 800 MPa-grade easy-welding hydroelectric steel plate comprises the following processes: the method comprises the following steps of molten iron pretreatment, converter smelting, LF external refining, RH vacuum degassing, continuous casting, slab heating, rolling, cooling and heat treatment; wherein:
in the molten iron pretreatment process, the S content is less than or equal to 0.005 percent after the molten iron is subjected to desulfurization pretreatment, and slag is removed after desulfurization;
in the process of converter smelting, LF external refining and RH vacuum degassing, a converter adopts single slag operation, and the alkalinity of final slag is controlled to be 3.0-3.5; the converter bottom blowing gas adopts a full-process argon blowing mode, and then is refined outside an LF furnace for further deoxidation, desulfurization, inclusion removal and component and temperature adjustment; degassing the molten steel in an RH vacuum degassing stage to promote floating of impurities, wherein RH circulation gas adopts a full-process argon blowing mode to ensure that pure degassing time is more than 5 minutes, vacuum treatment is carried out for 20 minutes, vacuum is re-broken to carry out calcium treatment, and after the calcium treatment is finished, soft blowing time is ensured to be more than or equal to 10 minutes;
in the continuous casting process, electromagnetic stirring and light pressing are adopted, and the drawing speed is controlled to be 0.80-1.2m/min;
in the slab heating process, the slab on-furnace time and the tapping temperature are controlled, the on-furnace time is 250-320min, the soaking time is 30-60min, and the tapping temperature is 1220 +/-20 ℃;
in the rolling and cooling process, the rough rolling adopts single pass, the relative reduction rate of at least 2 passes is more than 14 percent, and the final temperature of the rough rolling is more than or equal to 1050 ℃; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the relative reduction rate of at least 2 passes is more than 14 percent, and the final rolling temperature of finish rolling is 820-850 ℃; laminar flow cooling equipment is adopted for cooling, a secondary system self-learning calculation result is adopted in a cooling mode, and the final cooling temperature is 630-680 ℃;
in the heat treatment process, a quenching and tempering process is adopted, the quenching temperature is 900-920 ℃, and the heat preservation time is 10-20 min; the tempering temperature is 600-650 ℃, and the heat preservation time is 20-40 min.
2. The 800 MPa-grade easy-welding hydroelectric steel plate as claimed in claim 1, which comprises the following chemical components in percentage by mass: c:0.074%, si:0.22%, mn:1.30%, P:0.011%, S:0.002%, alt:0.046%, nb:0.040%, ti 0.022%, V:0.047%, cr:0.42%, mo:0.35%, ni:0.55%, cu:0.21 percent, and the balance of Fe and inevitable impurities.
3. The 800 MPa-grade easy-welding hydroelectric steel plate as claimed in claim 1, which comprises the following chemical components in percentage by mass: c:0.076%, si:0.21%, mn:1.29%, P:0.013%, S:0.003%, alt:0.042%, nb:0.041%, ti of 0.019%, V:0.045%, cr:0.44%, mo:0.37%, ni:0.57%, cu:0.23 percent, and the balance of Fe and inevitable impurities.
4. The 800 MPa-grade easy-welding hydroelectric steel plate as claimed in claim 1, which comprises the following chemical components in percentage by mass: c:0.079%, si:0.21%, mn:1.35%, P:0.011%, S:0.001%, alt:0.040%, nb:0.046%, ti of 0.020%, V:0.046%, cr:0.43%, mo:0.40%, ni:0.60%, cu:0.21 percent, and the balance of Fe and inevitable impurities.
5. The 800 MPa-grade easy-welding hydroelectric steel plate as claimed in claim 1, which comprises the following chemical components in percentage by mass: c:0.080%, si:0.19%, mn:1.41%, P:0.010%, S:0.004%, alt:0.040%, nb:0.048%, ti 0.025%, V:0.048%, cr:0.46%, mo:0.41%, ni:0.80%, cu:0.25 percent, and the balance of Fe and inevitable impurities.
6. The 800 MPa-grade steel plate for the easy-welding hydropower of any one of claims 1-5, which has transverse impact energy at-40 ℃ of more than or equal to 185J, yield strength of more than or equal to 756MPa, tensile strength of more than or equal to 806MPa, elongation A of more than or equal to 16.2%, welding crack sensitivity coefficient Pcm:0.22 to 0.24 percent.
7. The steel plate for an easy-to-weld hydroelectric power grade of 800MPa according to any one of claims 1 to 6, having a thickness of 12.0mm to 90.0mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211461145.2A CN115896622A (en) | 2022-11-21 | 2022-11-21 | 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211461145.2A CN115896622A (en) | 2022-11-21 | 2022-11-21 | 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115896622A true CN115896622A (en) | 2023-04-04 |
Family
ID=86486509
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211461145.2A Pending CN115896622A (en) | 2022-11-21 | 2022-11-21 | 800 MPa-grade easy-welding hydroelectric steel plate with excellent low-temperature impact toughness |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115896622A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103290339A (en) * | 2013-06-29 | 2013-09-11 | 首钢总公司 | High-strength steel plate for 800MPa hydropower station pressure pipeline and production method thereof |
| CN104532148A (en) * | 2014-12-10 | 2015-04-22 | 南京钢铁股份有限公司 | 800MPa grade low-welding crack sensitive tempering type hydroelectric steel plate |
-
2022
- 2022-11-21 CN CN202211461145.2A patent/CN115896622A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103290339A (en) * | 2013-06-29 | 2013-09-11 | 首钢总公司 | High-strength steel plate for 800MPa hydropower station pressure pipeline and production method thereof |
| CN104532148A (en) * | 2014-12-10 | 2015-04-22 | 南京钢铁股份有限公司 | 800MPa grade low-welding crack sensitive tempering type hydroelectric steel plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2021179443A1 (en) | Ultra-thick container steel plate with good low-temperature impact toughness in core and manufacturing method therefor | |
| CN109628828B (en) | Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof | |
| WO2022022066A1 (en) | Steel board for polar marine engineering and preparation method therefor | |
| CN113817963A (en) | 1000 MPa-level low-welding-crack-sensitivity steel plate and production method thereof | |
| CN111926253B (en) | Hydrogen sulfide corrosion resistant high-strength toughness normalized steel and manufacturing method thereof | |
| CN111607748A (en) | High-flatness large-thickness lamellar tearing resistant 780CF-Z35 hydroelectric steel and manufacturing method thereof | |
| WO2023029282A1 (en) | Production method for high-strength steel plate for engineering machinery | |
| CN106435379A (en) | 550 MPa level extra-thick easy-welding high-toughness layered-tearing-resisting steel plate and manufacturing method thereof | |
| CN107988548B (en) | A kind of X80 Pipeline Steel Plate and its production method adapting to low temperature Naked dew environment | |
| CN114134407A (en) | Easy-to-weld steel plate with excellent low-temperature toughness at core for volute and manufacturing method thereof | |
| CN110983187A (en) | Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof | |
| CN113528936A (en) | Method for producing hot-rolled H-shaped steel for DH36 ocean engineering structure by adopting special-shaped blank | |
| CN108823489B (en) | 600 MPa-grade hydroelectric steel plate and production method thereof | |
| CN108411196A (en) | Tensile strength is 680MPa grades of large-scale mobile steelss for pressure vessel use and production method | |
| CN115141969A (en) | Production method of 800MPa grade hydropower steel | |
| CN111270169A (en) | Ni-containing alloy steel plate with excellent low-temperature toughness and production method thereof | |
| CN113025885A (en) | Low-yield-ratio high-strength pipeline steel plate with good HIC (hydrogen induced cracking) resistance and manufacturing method thereof | |
| CN111763880A (en) | Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof | |
| CN114622073B (en) | Method for improving low-temperature impact toughness of boron-containing steel by utilizing sub-temperature quenching | |
| CN112501494A (en) | EW420 extra-thick marine steel plate and manufacturing method thereof | |
| CN114164315B (en) | 1000 MPa-grade high-strength high-toughness easy-welding nano steel with thickness of 60-120 mm and preparation method thereof | |
| CN114406522B (en) | Welding wire for overlaying repair of hot-rolled backup roll and preparation method thereof | |
| CN114134301B (en) | Two-fire rolling method of 1000 MPa-level steel plate for hydropower | |
| CN114058960B (en) | High-strength high-toughness easy-welding nano steel with thickness of 25-60 mm and thickness of 1000MPa and preparation method thereof | |
| CN115927952A (en) | 690 MPa-grade low-welding-crack-sensitivity quenched and tempered steel with hydrogen-induced delayed fracture resistance and manufacturing 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 |