CN115807193A - 'Suhua' continuous casting roller blank material system and preparation method thereof - Google Patents
'Suhua' continuous casting roller blank material system and preparation method thereof Download PDFInfo
- Publication number
- CN115807193A CN115807193A CN202211663335.2A CN202211663335A CN115807193A CN 115807193 A CN115807193 A CN 115807193A CN 202211663335 A CN202211663335 A CN 202211663335A CN 115807193 A CN115807193 A CN 115807193A
- Authority
- CN
- China
- Prior art keywords
- percent
- continuous casting
- steel
- blank material
- material system
- 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
- 239000000463 material Substances 0.000 title claims abstract description 63
- 238000009749 continuous casting Methods 0.000 title claims abstract description 52
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 229910052796 boron Inorganic materials 0.000 claims abstract description 31
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 20
- 239000000956 alloy Substances 0.000 claims abstract description 20
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 20
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 19
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 17
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 13
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 13
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 10
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 10
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 9
- 238000011282 treatment Methods 0.000 claims abstract description 8
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 6
- 229910000831 Steel Inorganic materials 0.000 claims description 84
- 239000010959 steel Substances 0.000 claims description 84
- 238000005242 forging Methods 0.000 claims description 46
- 238000005496 tempering Methods 0.000 claims description 36
- 238000000034 method Methods 0.000 claims description 30
- 238000010438 heat treatment Methods 0.000 claims description 27
- 230000008569 process Effects 0.000 claims description 25
- 238000003723 Smelting Methods 0.000 claims description 23
- 238000010791 quenching Methods 0.000 claims description 19
- 230000000171 quenching effect Effects 0.000 claims description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 16
- 229910052757 nitrogen Inorganic materials 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 11
- 229910000604 Ferrochrome Inorganic materials 0.000 claims description 10
- 229910001200 Ferrotitanium Inorganic materials 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 10
- 229910001309 Ferromolybdenum Inorganic materials 0.000 claims description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 9
- 238000005266 casting Methods 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 7
- 229910000616 Ferromanganese Inorganic materials 0.000 claims description 5
- 229910000592 Ferroniobium Inorganic materials 0.000 claims description 5
- 229910000519 Ferrosilicon Inorganic materials 0.000 claims description 5
- 229910000628 Ferrovanadium Inorganic materials 0.000 claims description 5
- 230000006698 induction Effects 0.000 claims description 5
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 claims description 5
- ZFGFKQDDQUAJQP-UHFFFAOYSA-N iron niobium Chemical compound [Fe].[Fe].[Nb] ZFGFKQDDQUAJQP-UHFFFAOYSA-N 0.000 claims description 5
- PNXOJQQRXBVKEX-UHFFFAOYSA-N iron vanadium Chemical compound [V].[Fe] PNXOJQQRXBVKEX-UHFFFAOYSA-N 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 abstract description 11
- 238000004227 thermal cracking Methods 0.000 abstract description 4
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 19
- 239000011651 chromium Substances 0.000 description 15
- 229910001566 austenite Inorganic materials 0.000 description 12
- 150000001247 metal acetylides Chemical class 0.000 description 12
- 239000010955 niobium Substances 0.000 description 12
- 229910000859 α-Fe Inorganic materials 0.000 description 10
- 229910052580 B4C Inorganic materials 0.000 description 9
- 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 9
- 229910001563 bainite Inorganic materials 0.000 description 9
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 238000005728 strengthening Methods 0.000 description 9
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 8
- 239000011572 manganese Substances 0.000 description 8
- 239000010936 titanium Substances 0.000 description 8
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 7
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 239000011733 molybdenum Substances 0.000 description 6
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 6
- 238000001556 precipitation Methods 0.000 description 6
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 238000005275 alloying Methods 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 229910052698 phosphorus Inorganic materials 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 229910000734 martensite Inorganic materials 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 3
- FFBHFFJDDLITSX-UHFFFAOYSA-N benzyl N-[2-hydroxy-4-(3-oxomorpholin-4-yl)phenyl]carbamate Chemical compound OC1=C(NC(=O)OCC2=CC=CC=C2)C=CC(=C1)N1CCOCC1=O FFBHFFJDDLITSX-UHFFFAOYSA-N 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910001562 pearlite Inorganic materials 0.000 description 2
- 239000010970 precious metal Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 230000007847 structural defect Effects 0.000 description 2
- BKUKXOMYGPYFJJ-UHFFFAOYSA-N 2-ethylsulfanyl-1h-benzimidazole;hydrobromide Chemical compound Br.C1=CC=C2NC(SCC)=NC2=C1 BKUKXOMYGPYFJJ-UHFFFAOYSA-N 0.000 description 1
- 229910001149 41xx steel Inorganic materials 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004931 aggregating effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- -1 boron carbides Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Landscapes
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a 'vegetalized' continuous casting roll blank material system and a preparation method thereof, belonging to the technical field of continuous casting roll materials. The invention relates to a 'vegetalization' continuous casting roll blank material system, which comprises the following components in percentage by mass: 0.30 to 0.34 percent of C,0.20 to 0.30 percent of Si,0.80 to 1.20 percent of Mn,0.15 to 0.25 percent of Cr,0.10 to 0.20 percent of Mo,0.030 to 0.040 percent of Ti,0.030 to 0.040 percent of Nb,0.030 to 0.040 percent of V,0.030 to 0.040 percent of Al,0.001 to 0.0065 percent of B and the balance of Fe, wherein the original continuous casting roll blank material system is subjected to 'basification' treatment, and a small amount of alloy elements such as Mn, ti, nb, V, B and the like are utilized to replace partial alloy elements such as Cr, ni and Mo in the roll blank material, so that the addition amount of precious alloy elements such as Cr, ni and Mo in the continuous casting roll blank is relatively reduced, the addition amount of the Cr, ni and Mo in the roll blank material is ensured on the basis of toughness, thermal cracking resistance and the like, and the production cost of the continuous casting roll blank material system is reduced. Solves the problems that the production cost of the roller blank is continuously improved and the obdurability and the thermal cracking resistance of the roller blank can not be considered because the performance requirement of the roller blank is continuously improved in the prior art.
Description
Technical Field
The invention belongs to the technical field of continuous casting roller materials, and particularly relates to a 'vegetarian' continuous casting roller blank material system and a preparation method thereof.
Background
The continuous casting roll is one of the main parts constituting continuous casting equipment in metallurgical industry, and plays the role of supporting, guiding, clamping and straightening casting blank in the process of continuous casting. The continuous casting roller drives the red blank in the working process, and the surface temperature can reach 600 ℃; the billet is cooled by water spraying, and the surface of the continuous casting roller is subjected to quenching action. Therefore, the continuous casting roll is subjected to high temperature, high humidity and cold and hot circulation for a long time, and is also subjected to alternating mechanical stress action of slab bulging force and static pressure, and the like, which can cause the problems of crack, oxidation corrosion, abrasion damage and the like on the surface of the continuous casting roll after being used for a period of time, so that the service life of the continuous casting roll is reduced, and the requirement of the continuous casting roll on the material performance is higher. The roller blank is the roller core part of the composite continuous casting roller, mainly plays a role of supporting the continuous casting roller, and compared with the high requirement of a hard surface layer on the comprehensive performance, the roller blank only needs to have certain strength and toughness. The common roll blank material mainly comprises bainite and tempered sorbite, and the lower bainite, granular bainite and tempered sorbite have good obdurability, meet the requirements of the roll blank material on comprehensive mechanical properties, particularly the tempered sorbite not only has good obdurability, but also has good anti-hot cracking performance, and can effectively protect the working life of the roll blank material in a high-temperature environment.
With the continuous improvement of the requirements on the performance of the roller blank in recent years, researchers add more and more alloy elements into the roller blank material, so that the production cost of the roller blank is continuously improved, the improvement space of the performance of the roller blank is smaller and smaller, and the development of the roller blank material enters a bottleneck.
In the eighties of the last century, hitachi, japan developed a series of roll blank materials R71-R73 in order to improve the performance of the roll blank, wherein the chemical composition of R73 is as follows (weight%): c is less than or equal to 0.25%, si:0.2 to 0.4%, mn:0.6 to 0.9 percent, cr:0.9 to 1.2%, mo:0.3 to 0.5%, ni:0.8 to 1.2%, V:0.05 to 0.15%, al:0.01 to 0.04 percent, less than or equal to 0.003 percent of P, less than or equal to 0.003 percent of S and the balance of Fe. The R73 material has higher strength and excellent toughness, can well meet the requirements of the material performance of the roll blank, but has higher content of precious metal elements in the R73 material.
In the early twenty-first century, aiming at the problems in the use of KRC14 slab continuous casting rolls, the saddle steel group designs a new bainite steel which comprises the following chemical components in percentage by weight: c:0.15 to 0.25%, si:0.80 to 1.20%, mn: 2.20-2.60%, cr:0.80 to 1.20%, mo:0.50 to 0.80%, ni:0.40 to 0.60 percent of the total weight of the alloy, less than or equal to 0.035 percent of B, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S and the balance of Fe. The steel has the advantages that the C curve is shifted to the right by adding more Mn elements to replace partial Ni elements, the transformation area of pearlite and pro-eutectoid ferrite is avoided, the material strength is improved, and the cost is reduced.
Disclosure of Invention
1. Technical problem to be solved
Aiming at the problems that the continuous improvement of the performance requirements of the roller blank in the prior art causes the continuous improvement of the production cost of the roller blank and the toughness and the thermal cracking resistance of the roller blank can not be considered at the same time, the invention utilizes a small amount of alloy elements such as Mn, ti, nb, V, B and the like to replace part of alloy elements such as Cr, ni and Mo in the roller blank material, thereby achieving the purposes of reducing the addition of precious alloy elements such as Cr, ni and Mo in the continuous casting roller blank and reducing the production cost of the roller blank on the basis of ensuring the performances such as the toughness, the thermal cracking resistance and the like of the roller blank.
2. Technical scheme
In order to solve the above problems, the present invention adopts the following technical solutions.
In the application, the expression "materialization" means that the performance of the material is improved by regulating and controlling the structure of the cross-scale material tissue, and the material replaces precious or rare elements in the alloying process, so that the alloy content in the material is reduced to the greatest extent, and resources and cost are saved.
The invention relates to a 'vegetalized' continuous casting roll blank material system, which comprises the following components in percentage by mass: 0.30 to 0.34 percent of C,0.20 to 0.30 percent of Si,0.80 to 1.20 percent of Mn,0.15 to 0.25 percent of Cr,0.10 to 0.20 percent of Mo,0.030 to 0.040 percent of Ti,0.030 to 0.040 percent of Nb,0.030 to 0.040 percent of V,0.030 to 0.040 percent of Al,0.001 to 0.0065 percent of B and the balance of Fe, wherein the original continuous casting roll blank material system is subjected to 'pixilation' treatment, and a small amount of alloy elements such as Mn, ti, nb, V, B and the like are utilized to replace partial alloy elements such as Cr, ni and Mo in the roll blank material, so that the addition amount of precious alloy elements such as Cr, ni and Mo in the roll blank of the continuous casting roll is relatively reduced, and the production cost of the continuous casting roll blank material system is reduced on the basis of ensuring the performances such as toughness, heat cracking resistance and the like of the roll blank.
In the 'vegetated' continuous casting roll blank material system, a proper amount of boron and a protective component titanium element are added into 'vegetated' steel, so that the boron element is easy to be separated out in the form of free boron and boron carbide at an austenite crystal boundary, the free boron can reduce the energy at the crystal boundary and delay the nucleation of ferrite and bainite, and the hardenability is improved; the fine boron carbide can pin the grain boundary and improve the stability of the grain boundary.
The 'element-containing' steel does not contain nickel element, and the addition amount of elements such as chromium, molybdenum and the like is less, compared with the conventional 42CrMo roller blank material, the content of precious alloy elements in the 'element-containing' steel is reduced by about 70%, the mechanical property of the 'element-containing' steel is equivalent to that of the 42CrMo roller blank material, and the production cost of the roller blank is obviously reduced on the premise of ensuring the mechanical property of the roller blank material.
A method for preparing a 'vegetarian' continuous casting roller blank material system comprises the following steps:
s1, high-temperature smelting: putting aluminum particles, ferrosilicon, ferromanganese, ferrochromium, ferrotitanium, ferroniobium, ferrovanadium, ferroboron and ferromolybdenum into a vacuum induction furnace according to the proportion, smelting at high temperature, and casting into square ingots after smelting is finished; the high temperature here means a high temperature of 1600 to 1700 ℃.
S2, forging: forging the square ingot into a continuous casting roller blank;
s3, tempering: after flaw detection of forging processing is qualified, quenching and tempering are carried out on the forged steel bar
The further preparation method comprises the following steps of (1) in the high-temperature smelting, firstly adding aluminum particles to deoxidize molten steel, then adding ferrotitanium to carry out alloying and nitrogen fixation, and finally adding ferrochrome, ferromolybdenum and ferroboron, wherein the stirring is carried out for 120 +/-10S after each addition; in the step S2, the forging ratio is 5; in the step S3, in the tempering, twice normalizing and tempering treatments are carried out, and the specific process is as follows: firstly heating the forging stock to 940-980 ℃, preserving heat for 3-4 h, then air-cooling to room temperature, then heating the steel to 910-930 ℃, preserving heat for 3-4 h, then air-cooling to room temperature, then heating the steel to 860-890 ℃, preserving heat for 3-4 h, then water-quenching, and finally tempering at 600-640 ℃ for 3-5 h.
3. Advantageous effects
Compared with the prior art, the invention has the beneficial effects that:
(1) According to the material system of the 'vegetarian' continuous casting roller blank, microalloying is carried out on the 'vegetarian' steel by adding titanium, niobium and vanadium microalloying elements, the strength and toughness of the 'vegetarian' steel are obviously improved in a fine grain strengthening and precipitation strengthening mode, wherein the tensile strength reaches 700-750 MPa, and the impact reaches 40-60J;
(2) According to the 'vegetalized' continuous casting roll blank material system, a proper amount of boron and a protective component titanium element are added, so that the boron element is easy to be separated out in the form of free boron and boron carbide at an austenite crystal boundary, the free boron can reduce the energy at the crystal boundary and delay the nucleation of ferrite and bainite, and the hardenability is improved; fine boron carbide can pin the grain boundary, and the stability of the grain boundary is improved;
(3) The 'element-containing' continuous casting roll blank material system does not contain nickel element, and the addition amount of elements such as chromium, molybdenum and the like is less, compared with the common 42CrMo roll blank material, the content of precious alloy elements in 'element-containing' steel is reduced by about 70 percent, and the mechanical property of 'element-containing' steel is equivalent to 42 CrMo; on the premise of ensuring the mechanical property of the roller blank material, the production cost of the roller blank is obviously reduced;
(4) The preparation method of the 'vegetalized' continuous casting roller blank material system aims at the problems that the 'vegetalized' steel has large grains, generates a banded structure and the like in the hot processing process, and before the final heat treatment process, the 'vegetalized' steel is subjected to preliminary heat treatment, the grains are refined, the structural defects are eliminated and the like, so that the mechanical property of the 'vegetalized' steel is improved, two times of normalizing treatment are selected as the preliminary heat treatment process of the roller blank material, two times of normalizing and quenching and tempering are adopted as the heat treatment process, a uniform tempered sorbite structure is obtained, the obdurability of the roller blank is improved, and the process is simple and reliable.
Drawings
FIG. 1 is a scanning electron microscope organization chart of a 'vegetalized' continuous casting roll blank, wherein:
(a) Example 1; (b) example 2; (c) example 3;
FIG. 2 is a transmission electron microscope image of Microalloy Carbide (MC) precipitation in the "materialized" continuous casting roll blank of example 1;
FIG. 3 is a transmission electron microscope morphology of boron carbide precipitation in the "pixelated" continuous casting roll blank of example 2, wherein: inset is the diffraction pattern of boron carbide transmission electron microscope.
Detailed Description
For a further understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings and examples.
The materialized continuous casting roller blank material system of the embodiment comprises the following components in percentage by mass: 0.30 to 0.34 percent of C,0.20 to 0.30 percent of Si,0.80 to 1.20 percent of Mn,0.15 to 0.25 percent of Cr,0.10 to 0.20 percent of Mo,0.030 to 0.040 percent of Ti,0.030 to 0.040 percent of Nb,0.030 to 0.040 percent of V,0.030 to 0.040 percent of Al,0.001 to 0.0065 percent of B, and the balance of Fe, wherein the basis of the formulation of each component is as follows:
carbon: in the roll blank material, on one hand, C and elements such as Cr, mo, ti, nb, V and the like are ensured to form a sufficient amount of fine carbides, and the dispersion strengthening effect is achieved during tempering; on the other hand, it is necessary to ensure that a certain amount of C is in solid solution in the matrix to achieve the effect of solid solution strengthening. When the carbon content is too low, only a small amount of carbon is dissolved in austenite, and the formed carbides are also small, which results in a great reduction in the strength, hot hardness, and other properties of the material; when the carbon content is too high, too much carbide is generated in the material, which causes segregation and growth of carbide, resulting in great decrease in toughness, bending resistance, etc. of the material. Therefore, the C content is controlled to be 0.30 to 0.34%.
Silicon: si is a non-carbide forming element and can improve the tempering stability and reduce the tempering brittleness; however, when silicon is added in excess, inclusions are easily formed, which affects the toughness of the material. Therefore, the Si content is controlled to 0.20 to 0.30%.
Manganese: mn is a strong austenite forming element and can improve the hardenability of the steel; when the content of manganese is too high, high-temperature tempering brittleness can occur during high-temperature tempering, the problems of coarse grains and the like easily occur after heat treatment, and the performance of the material is influenced. Therefore, the manganese content is controlled to be 0.80 to 1.20%.
Chromium: cr is a strong carbide forming element, the chromium-containing steel can be subjected to secondary hardening during high-temperature tempering, fine special carbides are separated out from martensite, the dispersion strengthening effect of a second phase is exerted, the hardness is improved, chromium can be dissolved in austenite, the CCT curve is shifted to the right, the hardenability of the steel is improved, and the structure and the carbides are refined. In order to reduce the use of precious metals, the chromium content is controlled to be 0.15-0.25%.
Molybdenum: mo has a good solid solution strengthening effect, can improve the hardness and the hardenability of steel, and can prevent carbide from aggregating in the tempering process, so that the high-temperature stability and the toughness of the steel are improved; however, molybdenum is expensive, and therefore, the content of molybdenum is controlled to 0.10 to 0.20%.
Titanium: ti is a strong carbide forming element, tiC particles which are dispersed can effectively improve the strength and the hardness of steel, in boron-containing steel, ti can also be used as a protective component to react with nitrogen in the steel to generate more stable TiN, and the reduction of the toughness and the hardenability of the steel caused by the generation of BN by the reaction of boron and nitrogen is prevented. Therefore, the content of titanium is controlled to 0.030 to 0.040%.
Niobium: nb is an important element for grain refinement, niobium has high affinity with carbon and nitrogen and mainly exists in the form of Nb (C, N) in steel, and the precipitation temperature of Nb (C, N) is high and is above 1300 ℃, so austenite preferentially forms nuclei on the surface of the Nb (C, N), the more austenite nuclei are precipitated on the surface of the Nb (C, N), and the better the refinement effect of austenite grains is. However, niobium is expensive and is not easily added too much, and therefore, the content of niobium is controlled to 0.030 to 0.040%.
Vanadium: the effect of V is similar to that of Ti. Vanadium is also an expensive element, and excessive addition of vanadium increases production cost, so that the content of vanadium is controlled to be 0.030-0.040%.
Boron: boron is one of the most common alloy elements for improving the hardenability of the steel, when a small amount of boron enters a matrix, the hardenability of the matrix can be effectively improved, and the rest boron can be combined with elements such as iron, chromium and the like to form alloy boride, so that the hardness and the wear resistance of the steel are improved; however, the addition of excessive boron reduces the toughness and plasticity of the steel. Moreover, the 'element-containing' steel is easy to separate out in the form of free boron and boron carbide at an austenite grain boundary by adding a proper amount of boron and a protective component titanium element, and the free boron can reduce the energy at the grain boundary and delay the nucleation of ferrite and bainite so as to improve the hardenability; the fine boron carbide can pin the grain boundary and improve the stability of the grain boundary. Therefore, the boron content is controlled to 0.001 to 0.0065%.
The microalloying method is characterized in that titanium, niobium and vanadium microalloying elements are added to microalloy the 'vegetated' steel, the strength and toughness of the 'vegetated' steel are obviously improved in a fine grain strengthening and precipitation strengthening mode, the tensile strength reaches 700-750 MPa and the impact reaches 40-60J through detection, and the strength, toughness and hot cracking resistance of the roll blank are considered while the production cost of the roll blank is reduced.
Example 1
The materialized continuous casting roller blank material system and the preparation method thereof comprise the following specific steps:
s1, high-temperature smelting: putting aluminum particles, ferrosilicon, ferromanganese, ferrochromium, ferrotitanium, ferroniobium, ferrovanadium, ferroboron and ferromolybdenum into a vacuum induction furnace according to the proportion, smelting at high temperature, and casting into square ingots after smelting is finished; the vacuum degree is ensured to be less than 10 in the smelting process -1 Pa; the low vacuum degree leads to difficult deoxidation in the smelting process, and the high vacuum degree and the high equipment cost.
In order to ensure the components of the smelted molten steel, firstly adding aluminum particles for deoxidation, then adding ferrotitanium for alloying and nitrogen fixation, and finally adding ferrochrome, ferromolybdenum and ferroboron, stirring for 120 +/-10 seconds by using a high-power stirrer after each addition, thereby obtaining the 'vegetalized' steel with the following chemical components and mass fractions: c:0.33%, si:0.26%, mn:0.98%, cr:0.21%, mo:0.15%, ti:0.039%, nb:0.035%, V:0.035%, al:0.035%, B:0.001%, P:0.0023%, S:0.002%, and the balance of Fe, and casting into square ingots after the smelting is finished;
s2, forging: forging the square ingot into a continuous casting roller blank; the forging ratio is 3-5, preferably 5, to ensure the compactness and the homogenization of the components of the forging stock, wherein the forging process comprises the following steps: the initial forging temperature is 1100 ℃, the final forging temperature is 900 ℃, and the forging is carried out to form a forging circle with the diameter of about 200 mm;
s3, tempering: after the forging processing flaw detection is qualified, normalizing and quenching and tempering are carried out on the forged steel bar for two times, and the specific process is as follows: after the flaw detection of the forging process is qualified, normalizing and quenching and tempering are carried out on the forged steel bar for two times, and the specific process comprises the following steps: firstly heating the forging stock to 940-980 ℃, preferably 950 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 910-930 ℃, preferably 920 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 860-890 ℃, preferably 880 ℃, preserving heat for 3-4 h, preferably 3h, then quenching by water, and finally tempering at 600-640 ℃, preferably 620 ℃ for 3-5, preferably 5h.
The resulting structure is shown in FIG. 1 (a). As shown in FIG. 1 (a), the "ferritic" steel of the present embodiment has a uniform structure, which is composed of tempered sorbite and a small amount of ferrite; as shown in FIG. 2 (transmission electron microscope appearance of microalloy carbide (MC, wherein M is Ti, nb and V) precipitated in a continuous casting roll blank), the 'vegetarian steel of the embodiment is dispersed with fine carbides of TiC, nbC, VC and the like, the diameter of the carbides is about 10-20 nm, the dispersed nano carbides refine the grains of the' vegetarian steel and improve the strength and toughness, and through grain size grading, the average grain size grade of the 'vegetarian' steel of the embodiment is 7.5-8.5 grade, the tensile strength Rm is 706MPa, the elongation A after forging is 18.5 percent, and the impact power KV is 57.3J.
Example 2
The materialized continuous casting roller blank material system and the preparation method thereof comprise the following specific steps:
s1, high-temperature smelting: putting aluminum particles, ferrosilicon, ferromanganese, ferrochromium, ferrotitanium, ferroniobium, ferrovanadium, ferroboron and ferromolybdenum into a vacuum induction furnace according to the proportion, smelting at high temperature, and casting into square ingots after the smelting is finished; the vacuum degree is ensured to be less than 10 in the smelting process -1 Pa；
In order to ensure the components of the smelted molten steel, firstly adding aluminum particles for deoxidation, then adding ferrotitanium for alloying and nitrogen fixation, and finally adding ferrochrome, ferromolybdenum and ferroboron, stirring for 120 +/-10 seconds by using a high-power stirrer after each addition, thereby obtaining the 'vegetalized' steel with the following chemical components and mass fractions: c:0.33%, si:0.26%, mn:0.98%, cr:0.21%, mo:0.15%, ti:0.039%, nb:0.035%, V:0.035%, al:0.035%, B:0.003%, P:0.0023%, S:0.002%, and the balance of Fe, and casting into square ingots after the smelting is finished;
s2, forging: forging the square ingot into a continuous casting roller blank; the forging ratio is 3-5, preferably 5, wherein the forging process comprises the following steps: the initial forging temperature is 1100 ℃, the final forging temperature is 900 ℃, and the forging is carried out to form a forging circle with the diameter of about 200 mm;
s3, tempering: after the forging processing flaw detection is qualified, normalizing and quenching and tempering are carried out on the forged steel bar for two times, and the specific process is as follows: firstly heating the forging stock to 940-980 ℃, preferably 950 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 910-930 ℃, preferably 920 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 860-890 ℃, preferably 880 ℃, preserving heat for 3-4 h, preferably 3h, then quenching by water, and finally tempering at 600-640 ℃, preferably 620 ℃ for 3-5, preferably 5h.
As can be seen from FIG. 1 (b), the structure of the "ferritic" steel of this example was composed of tempered sorbite and a small amount of ferrite. In addition to the precipitation of dispersed TiC, nbC, VC and other carbides having similar sizes as in example 1, M23 (B, C) 6 (M is a carbide forming element) having a diameter of about 40 to 70nm is precipitated at and near the grain boundaries of the "ferritic" steel of this example, and as can be seen from FIG. 3, fine boron carbides pin the grain boundaries, which not only hinder the movement of the grain boundaries but also bend the grain boundaries and increase the area during heating in the heat treatment, thereby contributing to the improvement of mechanical properties. By grain size grading, the "vegetalized" steel of this example has an average grain size grade of 7.5 to 8.5, a tensile strength Rm of 697MPa, an elongation A after forging of 20%, and a work of impact KV of 51.3J.
Example 3
The materialized continuous casting roll blank material system and the preparation method thereof of the embodiment comprise the following specific steps:
s1, high-temperature smelting: proportionally adding Al particles, ferrosilicon, ferromanganese, ferrochromium, ferrotitanium, ferroniobium, ferrovanadium, ferroboron and ferromolybdenumSmelting at high temperature in an air induction furnace, and pouring into square ingots after smelting is finished; the vacuum degree is ensured to be less than 10 in the smelting process -1 Pa；
In order to ensure the components of the smelted molten steel, firstly adding aluminum particles for deoxidation, then adding ferrotitanium for alloying and nitrogen fixation, and finally adding ferrochrome, ferromolybdenum and ferroboron, stirring for 120 +/-10 seconds by using a high-power stirrer after each addition, thereby obtaining the 'vegetalized' steel with the following chemical components and mass fractions: c:0.33%, si:0.26%, mn:1.04%, cr:0.21%, mo:0.16%, ti:0.035%, nb:0.037%, V:0.037%, al:0.028%, B:0.006%, P:0.0026%, S:0.0025 percent and the balance of Fe, and casting into square ingots after the smelting is finished;
s2, forging: forging the square ingot into a continuous casting roller blank; the forging ratio is 3-5, preferably 5, wherein the forging process comprises the following steps: the initial forging temperature is 1100 ℃, the final forging temperature is 900 ℃, and the forging is carried out to form a forging circle with the diameter of about 200 mm;
s3, tempering: after the forging processing flaw detection is qualified, normalizing and quenching and tempering are carried out on the forged steel bar for two times, and the specific process is as follows: after the forging processing flaw detection is qualified, normalizing and quenching and tempering are carried out on the forged steel bar for two times, and the specific process is as follows: firstly heating the forging stock to 940-980 ℃, preferably 950 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 910-930 ℃, preferably 920 ℃, preserving heat for 3-4 h, preferably 3h, then cooling to room temperature by air, then heating the steel to 860-890 ℃, preferably 880 ℃, preserving heat for 3-4 h, preferably 3h, then quenching by water, and finally tempering at 600-640 ℃, preferably 620 ℃ for 3-5, preferably 5h.
As can be seen from FIG. 1 (c), the structure of the "ferritic" steel of this example is composed of tempered sorbite + a small amount of ferrite; in the 'vegetarian' steel, tiny micro-alloy carbides of TiC, nbC, VC and the like are dispersed and distributed, 40-70 nm of boron carbide is also precipitated at an austenite crystal boundary, and the dispersed and distributed tiny carbides and boron nitride refine grains and improve the strength and toughness of the 'vegetarian' steel. By grain size grading, the average grain size grade of the 'vegetarian' steel of the embodiment is 7.5-8.5 grades, the tensile strength Rm is 759MPa, the elongation A after forging is 19 percent, and the impact energy KV is 42.3J.
In the material system of the materialized ' continuous casting roll blank of the embodiments 1 to 3, nickel element is not contained, and the addition amount of elements such as chromium, molybdenum and the like is small, and through detection, compared with the common 42CrMo roll blank material, the content of precious alloy elements in the materialized ' steel is reduced by about 70 percent, and the mechanical property of the materialized ' steel is equivalent to that of 42CrMo, and the specific properties are shown in Table 1:
TABLE 1 mechanical Properties of 42CrMo and materialized steels
On the premise of ensuring the mechanical property of the roller blank material, the production cost of the roller blank is obviously reduced. The basis of the heat treatment process of the 'vegetarian' steel by adopting twice normalizing and quenching and tempering is as follows:
the problems of coarse grains, generation of a banded structure and the like of the ' vegetarian steel during hot working are solved, so that the mechanical property of the ' vegetarian steel is improved by performing preliminary heat treatment on the ' vegetarian steel before a final heat treatment process, refining grains, eliminating structural defects and the like, and two times of normalizing treatment is selected as the preliminary heat treatment process of the roll blank material.
In order to obtain a uniform tempered sorbite structure and improve the toughness of the roll blank, the 'element steel' after the preliminary heat treatment is also subjected to thermal refining. When the quenching temperature is higher, austenite grains of the 'vegetated' steel become coarse, and the function of fine grain strengthening is reduced; when the quenching temperature is lower, alloy elements can not be completely dissolved in austenite, the hardenability of the steel can be reduced, so that a plurality of non-martensite structures such as pro-eutectoid ferrite, pearlite, bainite and the like can be generated in the quenching process, when the tempering treatment is carried out, the martensite can be converted into tempered sorbite, and the structures such as the ferrite, the bainite and the like can be remained, so that the toughness of the 'vegetalized' steel is influenced. After water quenching, the structure of the 'vegetated' steel is martensite plus a small amount of ferrite. After quenching, the 'vegetarian' steel has higher internal stress, tempering treatment needs to be carried out on the 'vegetarian' steel in order to eliminate the stress and stabilize the structure, and when the tempering temperature is higher or the tempering time is longer, the number of carbides in the 'vegetarian' steel is increased, the size of the carbides is increased, and the mechanical property of the 'vegetarian' steel is influenced; when the tempering temperature is low or the tempering time is short, the internal stress in the 'vegetated' steel can be eliminated incompletely, and the stability of the 'vegetated' steel is influenced.
The examples described herein are merely illustrative of the preferred embodiments of the present invention and do not limit the spirit and scope of the invention, and various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention should fall within the protection scope of the present invention.
Claims (5)
1. A 'vegetarian' continuous casting roll blank material system is characterized in that: the mass fraction of each component is as follows: 0.30 to 0.34 percent of C,0.20 to 0.30 percent of Si,0.80 to 1.20 percent of Mn,0.15 to 0.25 percent of Cr,0.10 to 0.20 percent of Mo,0.030 to 0.040 percent of Ti,0.030 to 0.040 percent of Nb,0.030 to 0.040 percent of V,0.030 to 0.040 percent of Al,0.001 to 0.0065 percent of B, and the balance of Fe.
2. A method for preparing the 'materialized' continuous casting roll blank material system of claim 1, which is characterized by comprising the following steps:
s1, high-temperature smelting: putting aluminum particles, ferrosilicon, ferromanganese, ferrochromium, ferrotitanium, ferroniobium, ferrovanadium, ferroboron and ferromolybdenum into a vacuum induction furnace according to the proportion, smelting at 1600-1700 ℃ and casting into square ingots after smelting;
s2, forging: forging the square ingot into a continuous casting roller blank;
s3, tempering: and after the forging processing is qualified for flaw detection, carrying out quenching and tempering treatment on the forged steel bar.
3. The method for preparing the 'materialized' continuous casting roll blank material system according to claim 2, which is characterized by comprising the following steps of: in the step S1 of high-temperature smelting, firstly adding aluminum particles to deoxidize molten steel, then adding ferrotitanium to alloy and fix nitrogen, and finally adding ferrochrome, ferromolybdenum and ferroboron, wherein stirring is carried out for 120 +/-10S after each addition.
4. The method for preparing the 'materialized' continuous casting roll blank material system according to claim 3, which is characterized by comprising the following steps of: in the step S2, the forging ratio is 3-5.
5. The materialized continuous casting roll blank material system and the preparation method thereof according to claim 4, wherein the material system comprises the following components in percentage by weight: in the step S3, in the tempering, twice normalizing, tempering and the specific process is as follows: firstly heating the forging stock to 940-980 ℃, preserving heat for 3-4 h, then air-cooling to room temperature, then heating the steel to 910-930 ℃, preserving heat for 3-4 h, then air-cooling to room temperature, then heating the steel to 860-890 ℃, preserving heat for 3-4 h, then water-quenching, and finally tempering at 600-640 ℃ for 3-5 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211663335.2A CN115807193B (en) | 2022-12-23 | 2022-12-23 | 'biotinylated' continuous casting roller blank material system and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211663335.2A CN115807193B (en) | 2022-12-23 | 2022-12-23 | 'biotinylated' continuous casting roller blank material system and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115807193A true CN115807193A (en) | 2023-03-17 |
| CN115807193B CN115807193B (en) | 2024-02-06 |
Family
ID=85486606
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211663335.2A Active CN115807193B (en) | 2022-12-23 | 2022-12-23 | 'biotinylated' continuous casting roller blank material system and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115807193B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11314145A (en) * | 1998-03-03 | 1999-11-16 | Nippon Steel Corp | Continuous casting roll excellent in crack resistance |
| CN101054649A (en) * | 2007-03-29 | 2007-10-17 | 攀钢集团成都钢铁有限责任公司 | Sulfur erosion resisting steel and smelting method thereof |
| JP2008057036A (en) * | 2006-07-31 | 2008-03-13 | Sumitomo Metal Ind Ltd | Method for manufacturing soft-nitriding non-normalizing machine part |
| CN101748329A (en) * | 2009-12-24 | 2010-06-23 | 马鞍山钢铁股份有限公司 | 610MPa automobile girder steel and production method thereof |
| CN103898419A (en) * | 2012-12-25 | 2014-07-02 | 隆英(金坛)特钢科技有限公司 | Wear-resisting steel plate and manufacturing method thereof |
| CN104532159A (en) * | 2014-12-19 | 2015-04-22 | 宝山钢铁股份有限公司 | 700MPa-grade (yield strength) quenched-tempered high-strength steel and production method thereof |
| CN105964964A (en) * | 2015-03-11 | 2016-09-28 | 斯凯孚公司 | Continuous caster roll for a continuous casting machine |
| CN111748730A (en) * | 2019-03-28 | 2020-10-09 | 宝山钢铁股份有限公司 | 900 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof |
-
2022
- 2022-12-23 CN CN202211663335.2A patent/CN115807193B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11314145A (en) * | 1998-03-03 | 1999-11-16 | Nippon Steel Corp | Continuous casting roll excellent in crack resistance |
| JP2008057036A (en) * | 2006-07-31 | 2008-03-13 | Sumitomo Metal Ind Ltd | Method for manufacturing soft-nitriding non-normalizing machine part |
| CN101054649A (en) * | 2007-03-29 | 2007-10-17 | 攀钢集团成都钢铁有限责任公司 | Sulfur erosion resisting steel and smelting method thereof |
| CN101748329A (en) * | 2009-12-24 | 2010-06-23 | 马鞍山钢铁股份有限公司 | 610MPa automobile girder steel and production method thereof |
| CN103898419A (en) * | 2012-12-25 | 2014-07-02 | 隆英(金坛)特钢科技有限公司 | Wear-resisting steel plate and manufacturing method thereof |
| CN104532159A (en) * | 2014-12-19 | 2015-04-22 | 宝山钢铁股份有限公司 | 700MPa-grade (yield strength) quenched-tempered high-strength steel and production method thereof |
| CN105964964A (en) * | 2015-03-11 | 2016-09-28 | 斯凯孚公司 | Continuous caster roll for a continuous casting machine |
| CN111748730A (en) * | 2019-03-28 | 2020-10-09 | 宝山钢铁股份有限公司 | 900 MPa-grade high-toughness high-magnetism hot-rolled magnetic yoke steel and production method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 徐淑娇;徐新华;陈国喜;秦威;盛俭生;成阳;邓琦林;: "21CrMoV5.11钢连铸辊断裂失效分析", 金属热处理, no. 01, pages 232 - 235 * |
| 钟毅;余光明;陈良奎;: "连铸辊断裂失效分析研究", 钢铁研究, no. 06, pages 38 - 40 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115807193B (en) | 2024-02-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110184532B (en) | Wear-resistant steel plate with excellent-60 ℃ ultralow-temperature impact toughness and production method thereof | |
| WO2021036271A1 (en) | High-temperature-resistant 400hb wear-resistant steel plate and method for production thereof | |
| CN109182901A (en) | A kind of linear guide steel and its hot rolling production method | |
| CN109913750B (en) | High-strength thin steel sheet having high surface quality and method for manufacturing the same | |
| CN108559917A (en) | A kind of yield strength 1100MPa grades of Ultra-fine Grained high strength steel plates and its manufacturing method | |
| CN109778068B (en) | Niobium-vanadium composite reinforced wear-resistant cast steel and preparation method thereof | |
| CN114480806A (en) | Manufacturing method of thick TiC particle enhanced martensite wear-resistant steel plate | |
| JPH10265846A (en) | Production of thermally refined high tensile strength steel plate by continuous casting excellent in toughness | |
| WO2019222988A1 (en) | Ultra-fine grained high-strength steel plate with 1100 mpa-grade yield strength and production method thereof | |
| CN1380436A (en) | High vanadium high-wear-resistant alloy and its preparation method | |
| WO2024120001A1 (en) | Low-cost q550d steel plate with mo replaced with v, and production method therefor | |
| CN111218540B (en) | High-boron iron-based wear-resistant alloy, preparation method and part thereof | |
| CN114351053B (en) | Superfine crystal high-toughness wear-resistant steel and manufacturing method thereof | |
| CN110306110A (en) | The HB500 grade easy-welding and wear-resistant steel and production method of a kind of thickness in 60 ~ 80mm | |
| CN113564470B (en) | 1700MPa heat-resistant steel for agricultural machinery and manufacturing method thereof | |
| CN115558870A (en) | Economical long-life steel for high-power wind power yaw bearing ring, bearing ring and production process | |
| CN115807193B (en) | 'biotinylated' continuous casting roller blank material system and preparation method thereof | |
| CN114875315A (en) | Low-alloy steel for excavator bucket teeth and production method thereof | |
| CN114107832A (en) | Large-size manual tool steel and preparation method thereof | |
| CN114703431A (en) | Heat treatment process for homogenizing hot-work die steel and annealing structure | |
| CN111057964B (en) | Steel for high-strength knuckle of new energy automobile and preparation method and application thereof | |
| CN113462986A (en) | 2000MPa environment-friendly heat-resistant steel for agricultural machinery and manufacturing method thereof | |
| CN114774804B (en) | 600 HB-grade hot-rolled low-cost wear-resistant steel plate and manufacturing method thereof | |
| CN116590625B (en) | High-performance fine grain pressure vessel steel plate and manufacturing method thereof | |
| CN109112405A (en) | A kind of railroad train band steel 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 |