KR20150076888A - Extremely thick steel sheet and method of manufacturing the same - Google Patents
Extremely thick steel sheet and method of manufacturing the same Download PDFInfo
- Publication number
- KR20150076888A KR20150076888A KR1020130165569A KR20130165569A KR20150076888A KR 20150076888 A KR20150076888 A KR 20150076888A KR 1020130165569 A KR1020130165569 A KR 1020130165569A KR 20130165569 A KR20130165569 A KR 20130165569A KR 20150076888 A KR20150076888 A KR 20150076888A
- Authority
- KR
- South Korea
- Prior art keywords
- steel sheet
- less
- cooling
- strength
- rolling
- Prior art date
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
Abstract
Description
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a steel sheet and a method of manufacturing the same, and more particularly, to a steel sheet having excellent weldability and a low temperature toughness at the center of the steel sheet, ≪ / RTI >
Due to the extreme consumption of global oil resources, future mining of energy resources in more harsh environments is required. In accordance with this trend, it is indispensable to ensure the strength and toughness at a lower temperature in the use environment of the marine structural steel sheet.
Particularly, in order to secure the strength in such an environment, a thicker steel sheet must be used. In this case, as the thickness of the steel becomes thicker, the impact toughness and crack tip opening displacement (CTOD) Efforts are being actively pursued.
A related prior art document is Korean Patent Publication No. 10-1997-0043155 (published on July 26, 1997).
An object of the present invention is to provide a method for manufacturing a very thin steel plate capable of increasing weldability and controlling low-temperature toughness at the center of a thickness by controlling alloy components and controlling process conditions through controlling alloy components and controlling process conditions .
Another object of the present invention is to provide a rubber composition which is produced by the above method and has a tensile strength (TS) of 460 to 600 MPa, a yield strength of 350 to 500 MPa, an elongation (EL) of 20 to 30% And to provide a superficial steel sheet.
In order to accomplish the above object, the present invention provides a method for manufacturing extreme-strength steel sheet, comprising: (a) 0.04 to 0.08% of C, 0.1 to 0.3% of Si, 1.2 to 1.8% of Mn, 0.05% 0.005% or less of S, 0.2% or less of Cr, 0.02 to 0.06% of S_Al, 0.15 to 0.50% of Cu, 0.020 to 0.045% of Nb, 0.3 to 1.0% of Ni, 0.01 to 0.03% of Ti, 0.01 to 0.03% of Ti, : 0.001 to 0.005% and the remaining iron (Fe) and other unavoidable impurities to 1000 to 1150 캜; (b) primary rolling the reheated plate in an austenite recrystallization zone; (c) secondarily rolling the primary rolled plate at a finishing rolling temperature (FRT) of 700 to 850 占 폚; And (d) cooling the secondary rolled plate to a finishing cooling temperature (FCT) of 350 to 500 ° C.
According to another aspect of the present invention, there is provided a steel sheet comprising: 0.04 to 0.08% of C, 0.1 to 0.3% of Si, 1.2 to 1.8% of Mn, 0.05% or less of P, 0.001 to 0.005%, Cr: 0.2% or less, S_Al: 0.02 to 0.06%, Cu: 0.15 to 0.50%, Nb: 0.020 to 0.045%, Ni: 0.3 to 1.0%, Ti: 0.01 to 0.03% % And remaining iron (Fe) and other inevitable impurities, and the final microstructure has a complex structure including acicular ferrite and bainite, wherein the acicular ferrite structure has a cross- 80%.
The extreme-strength steel sheet and the method of manufacturing the same according to the present invention are characterized in that, through controlling the alloy components and controlling the process conditions, the final microstructure has a composite structure including acicular ferrite and bainite, By controlling the cross sectional area ratio to be 70 to 80%, it is possible to induce miniaturization of the microstructure in the thickness direction, thereby improving impact toughness and crack tip opening displacement (CTOD) characteristics of the weld heat affected zone.
The tensile strength (TS) of 460 to 600 MPa and the yield strength of the extreme-strength steel sheet produced by the method according to the present invention have a carbon equivalent (Ceq) of 0.40 or less and a weld crack susceptibility index (Pcm) of 0.23 or less, 350 to 500 MPa, elongation (EL): 20 to 30%, and impact absorption energy at -60 DEG C: 400 J or more.
FIG. 1 is a process flow chart showing a method of manufacturing a extreme cold rolled steel sheet according to an embodiment of the present invention.
2 is a graph showing the impact test results of the specimens according to Examples 1 to 3.
3 is a photograph showing the final microstructure of the specimen according to Example 1. Fig.
The features of the present invention and the method for achieving the same will be apparent from the accompanying drawings and the embodiments described below. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. The present embodiments are provided so that the disclosure of the present invention is complete and that those skilled in the art will fully understand the scope of the present invention. The invention is only defined by the description of the claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.
Extreme steel plate
The extreme cold-rolled steel sheet according to the present invention has a tensile strength (TS) of 460 to 600 MPa, a yield strength of 350 to 500 MPa, an elongation (EL) of 0.25 or less, ): 20 to 30% and an impact absorption energy at -60 캜: 400 J or more.
The steel sheet according to the present invention contains 0.04 to 0.08% of C, 0.1 to 0.3% of Si, 1.2 to 1.8% of Mn, 0.05% or less of P, 0.005% or less of S, (Ni), 0.01 to 0.03% of Ti, 0.001 to 0.005% of Ca, 0.001 to 0.005% of Ca, and 0.001 to 0.005% of Ca, And other unavoidable impurities.
At this time, the steel sheet has a composite structure in which the final microstructure includes acicular ferrite and bainite, and the acicular ferrite structure has a cross-sectional area ratio of 70 to 80%.
Hereinafter, the role and content of each component included in the extreme-strength steel sheet according to the present invention will be described.
Carbon (C)
Carbon (C) is added to ensure strength.
The carbon (C) is preferably added in a content ratio of 0.04 to 0.08% by weight based on the total weight of the extreme cold rolled steel sheet according to the present invention. When the content of carbon (C) is less than 0.04% by weight, it may be difficult to secure sufficient strength. On the other hand, if the content of carbon (C) exceeds 0.08% by weight, toughness may be lowered.
Silicon (Si)
Silicon (Si) acts as a deoxidizer in the steel and contributes to securing strength.
The silicon (Si) is preferably added in an amount of 0.1 to 0.3% by weight based on the total weight of the extreme-strength steel sheet according to the present invention. When the content of silicon (Si) is less than 0.1% by weight, the effect of addition thereof can not be exhibited properly. On the contrary, when the content of silicon (Si) exceeds 0.3% by weight, the toughness and weldability of the steel sheet deteriorate.
Manganese (Mn)
Manganese (Mn) is an element useful for improving strength without deteriorating toughness.
The manganese (Mn) is preferably added in a content ratio of 1.2 to 1.8 wt% of the total weight of the extreme-strength steel sheet according to the present invention. When the content of manganese (Mn) is less than 1.2% by weight, the effect of addition thereof can not be exhibited properly. On the other hand, when the content of manganese (Mn) exceeds 1.8% by weight, there is a problem that the sensitivity to temper embrittlement is increased.
In (P)
Phosphorous (P) is added to inhibit cementite formation and increase strength.
However, phosphorus (P) may cause weldability to deteriorate and cause final material deviation by slab center segregation. Therefore, in the present invention, the content of phosphorus (P) is limited to a content ratio of 0.05% by weight or less of the total weight of the extreme steel sheet.
Sulfur (S)
Sulfur (S) inhibits the toughness and weldability of steel. In particular, the sulfur (S) bonds with manganese (Mn) to form MnS nonmetallic inclusions, thereby deteriorating the resistance against stress corrosion cracking, thereby causing cracks during steel processing.
Therefore, in the present invention, the content of sulfur (S) is limited to a content ratio of 0.005% by weight or less of the total weight of the extreme steel sheet.
Chromium (Cr)
Chromium (Cr) is a ferrite stabilizing element and contributes to strength improvement. Chromium (Cr) also plays a role in enlarging the delta ferrite region and shifting the hypo-peritectic region to the high carbon side to improve the slab surface quality.
However, when Cr (Cr) is added in an amount exceeding 0.2 wt%, the toughness of the weld heat affected zone (HAZ) is deteriorated. Therefore, it is preferable that chromium (Cr) is added at a content ratio of 0.2% by weight or less based on the total weight of the extreme-strength steel sheet according to the present invention.
Soluble Aluminum (S_Al)
Soluble aluminum (S_Al) acts as a deoxidizer to remove oxygen in the steel.
The soluble aluminum (S_Al) is preferably added in a content ratio of 0.02 to 0.06% by weight of the total weight of the extreme-strength steel sheet according to the present invention. When the content of soluble aluminum (S_Al) is less than 0.02% by weight, the above deoxidation effect can not be exhibited properly. On the contrary, when the content of soluble aluminum (S_Al) exceeds 0.06% by weight, it is difficult to perform, resulting in a decrease in productivity, and a compound which causes a pinning effect such as Al 2 O 3 to form a finer austenite crystal grain Lt; / RTI >
Copper (Cu)
Copper (Cu) contributes to solid solution strengthening and enhances strength.
The copper (Cu) is preferably added at a content ratio of 0.15 to 0.50 wt% of the total weight of the extreme-strength steel sheet according to the present invention. When the content of copper (Cu) is less than 0.15% by weight, the effect of the addition can not be exhibited properly. On the contrary, when the content of copper (Cu) exceeds 0.50% by weight, the hot workability of the steel sheet is lowered and the susceptibility to stress relief cracking after welding is increased.
Niobium (Nb)
Niobium (Nb) combines with carbon (C) and nitrogen (N) at high temperatures to form carbides or nitrides. Niobium carbide or nitride improves the strength and low-temperature toughness of a steel sheet by suppressing crystal grain growth during rolling and making crystal grains finer.
Niobium (Nb) is preferably added in a content ratio of 0.020 to 0.045% by weight of the total weight of the extreme-strength steel sheet according to the present invention. When the content of niobium (Nb) is less than 0.020% by weight, the effect of the addition can not be exhibited properly. On the contrary, when the content of niobium (Nb) exceeds 0.045% by weight, the weldability of the steel sheet is lowered, and the strength and low-temperature toughness are not improved any more, and they are present in a solid state in ferrite, have.
Nickel (Ni)
Nickel (Ni) is effective for improvement in toughness while improving incineration.
The nickel (Ni) is preferably added at a content ratio of 0.3 to 1.0 wt% of the total weight of the extreme cold-rolled steel sheet according to the present invention. When the content of nickel (Ni) is less than 0.3% by weight, the effect of addition thereof can not be exhibited properly. On the contrary, when the content of nickel (Ni) exceeds 1.0% by weight, the cold workability of the steel sheet is lowered. Also, the addition of excessive nickel (Ni) greatly increases the manufacturing cost of the steel sheet.
Titanium (Ti)
Titanium (Ti) has the effect of improving the toughness and strength of hot-rolled steel sheet by making Ti (C, N) precipitates having high stability at high temperatures, thereby finishing the austenite grain growth and refining the texture of the welded portion.
The titanium (Ti) is preferably added in an amount of 0.01 to 0.03% by weight based on the total weight of the extreme-strength steel sheet according to the present invention. When the content of titanium (Ti) is less than 0.01% by weight, there arises a problem that aging hardening occurs because of the remaining solid carbon and nitrogen employed without precipitation. On the contrary, when the content of titanium (Ti) exceeds 0.03% by weight, coarse precipitates are produced, which lowers the low-temperature impact properties of the steel and raises the manufacturing cost without further effect of addition.
Calcium (Ca)
Calcium (Ca) is added for the purpose of improving electrical resistance weldability by inhibiting the formation of MnS inclusions by forming CaS inclusions. That is, calcium (Ca) has a higher affinity with sulfur than manganese (Mn), so CaS inclusions are formed and CaS inclusions are reduced when calcium is added. Such MnS is stretched during hot rolling to cause hook defects and the like in electrical resistance welding (ERW), so that electrical resistance weldability can be improved.
The calcium (Ca) is preferably added at a content ratio of 0.001 to 0.005% by weight of the total weight of the extreme-strength steel sheet according to the present invention. If the content of calcium (Ca) is less than 0.001% by weight, the MnS control effect can not be exhibited properly. On the contrary, when the content of calcium (Ca) exceeds 0.005% by weight, generation of CaO inclusions is excessively generated, which deteriorates performance and electrical resistance weldability.
Meanwhile, the extreme ultra-fine steel sheet according to the present invention can be produced by mixing carbon (C), silicon (Si), manganese (Mn), copper (Cu), nickel (Ni) and chromium (Cr) .
[C] + [Mn / 6] + [(Cu + Ni) / 15] + [Cr / 5]
[C / 20] + [Ni / 60] + [Cr / 20] < / = 0.23
(Where [] is the weight percentage of each element)
At this time, when the carbon equivalent (Ceq) exceeds 0.45 or the welding crack susceptibility index (Pcm) exceeds 0.23, there is a high possibility that cracks are generated in the welded portion, so that carbon (C), silicon (Si), manganese (Mn), copper (Cu), nickel (Ni), and chromium (Cr).
Method of manufacturing extreme steel plate
FIG. 1 is a process flow chart showing a method of manufacturing a extreme cold rolled steel sheet according to an embodiment of the present invention.
Referring to FIG. 1, the method for manufacturing extreme-strength steel sheet according to an embodiment of the present invention includes a slab reheating step S110, a primary rolling step S120, a secondary rolling step S130, and a cooling step S140 do. At this time, the slab reheating step (S110) is not necessarily performed, but it is more preferable to carry out the step to derive effects such as reuse of precipitates.
The slab plate of the semi-finished product to be subjected to the hot rolling process according to the present invention comprises 0.04 to 0.08% of C, 0.1 to 0.3% of Si, 1.2 to 1.8% of Mn, 0.05% of P, 0.005% or less of S, 0.2% or less of Cr, 0.02 to 0.06% of S_Al, 0.15 to 0.50% of Cu, 0.020 to 0.045% of Nb, 0.3 to 1.0% of Ni, 0.01 to 0.03% of Ti, 0.01 to 0.03% of Ti, : 0.001 to 0.005% and the balance of iron (Fe) and other unavoidable impurities.
At this time, the slab plate having the above composition can be obtained through a continuous casting process after obtaining a molten steel having a desired composition through a steelmaking process.
Reheating slabs
In the slab reheating step S110, the slab plate having the above composition is reheated to a slab reheating temperature (SRT) of 1000 to 1150 ° C. Through the reheating of the slab plate, re-use of the segregated components and re-use of precipitates may occur during casting.
At this stage, when the slab reheating temperature (SRT) is less than 1000 ° C, there is a problem that the segregated components are not sufficiently reused during casting. On the contrary, when the SRT exceeds 1150 DEG C, the austenite grain size increases and the ferrite of the final microstructure is coarsened, so that it may be difficult to obtain strength, and the manufacturing cost of the steel sheet is increased only by the excessive heating process can do.
Primary rolling
In the primary rolling step (S120), the reheated plate is primarily rolled in the austenite recrystallization region. At this time, the austenite recrystallization region may be a condition of Roughing Delivery Temperature (RDT): 850 to 950 ° C, but is not limited thereto.
In this step, when the primary rolling finish temperature (RDT) is less than 850 ° C, time is required to secure the cooling time during the rough rolling pass, which may result in a decrease in productivity. On the other hand, when the primary rolling finish temperature (RDT) exceeds 950 占 폚, it may be difficult to secure a sufficient reduction rate.
Secondary rolling
In the secondary rolling step (S130), the primary rolled plate is secondarily rolled under the condition of FRT (Finishing Rolling Temperature): 700 to 850 ° C.
If the secondary rolling finishing temperature (FRT) is less than 700 ° C in this step, an abnormal reverse rolling occurs to form an uneven structure, which may significantly reduce the low temperature impact toughness. On the other hand, when the secondary rolling finishing temperature (FRT) exceeds 850 DEG C, the ductility and toughness are excellent but the strength is rapidly lowered.
At this time, the secondary rolling may be performed so that the cumulative rolling reduction in the non-recrystallized region is 60 to 80%. If the cumulative rolling reduction of the secondary rolling is less than 60%, it is difficult to obtain a uniform and fine structure, which may cause a significant variation in strength and impact toughness. On the other hand, when the cumulative reduction rate of the secondary rolling exceeds 80%, there is a problem that the rolling process time is prolonged and the fishy property is deteriorated.
Cooling
In the cooling step (S140), the secondary rolled plate is cooled to 700 to 800 占 폚 in SCT (Start Cooling Temperature) and 350 to 500 占 폚 in FCT (Finish Cooling Temperature).
In this step, when the cooling start temperature (SCT) is less than 700 캜, the fraction of the ascicular ferrite is too high and the strength may be lowered. On the other hand, when the cooling start temperature SCT exceeds 800 占 폚, if the accelerated cooling is sufficient, the strength is high but the yield ratio exceeds the target value and the deformability can not be ensured.
If the cooling end temperature (FCT) is lower than 350 ° C, the cost of producing steel increases, low-temperature structure is produced, which is advantageous in securing strength but is vulnerable to low-temperature toughness. Conversely, when the cooling end temperature (FCT) exceeds 500 캜, bainite is not formed and it may be difficult to secure sufficient strength.
In this step, the cooling rate is preferably 3 to 7 DEG C / sec. When the cooling rate is less than 3 DEG C / sec, it is difficult to secure sufficient strength and toughness. On the other hand, if the cooling rate exceeds 7 DEG C / sec, cooling control is difficult, and excessive cooling may adversely affect the shape of the steel sheet.
The ultrafine steel sheet manufactured in the above steps S110 to S140 may have a composite structure including final microstructures including acicular ferrite and bainite through control of alloy components and process conditions, Type ferrite structure is controlled to have a cross sectional area ratio of 70 to 80%, it is possible to induce miniaturization of the microstructure in the thickness direction and improve the impact toughness and crack tip opening displacement (CTOD) characteristics of the weld heat affected zone.
The tensile strength (TS): 460 to 600 MPa, the yield strength: 0.25 or less, the carbon steel equivalent (Ceq) of 0.45 or less and the weld crack susceptibility index (Pcm) 350 to 500 MPa, elongation (EL): 20 to 30%, and impact absorption energy at -60 DEG C: 400 J or more.
Example
Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.
The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.
1. Preparation of specimens
Specimens according to Examples 1 to 3 and Comparative Examples 1 to 3 were prepared with the compositions of Tables 1 and 2 and the process conditions of Table 3. At this time, in the case of the specimens according to Examples 1 to 3 and Comparative Examples 1 to 3, ingots having respective compositions were prepared and subjected to a hot rolling process of heating, primary rolling, secondary rolling and cooling using a rolling simulation tester Respectively.
[Table 1] (unit:% by weight)
[Table 2] (unit:% by weight)
[Table 3]
2. Evaluation of mechanical properties
Table 4 shows the results of evaluation of mechanical properties for the specimens according to Examples 1 to 3 and Comparative Examples 1 to 3, and FIG. 2 is a graph showing the results of impact toughness test for the specimens according to Examples 1 to 3 .
[Table 4]
(TS): 460 to 500 MPa, yield strength (YS): 350 to 500 MPa, and elongation (TS) corresponding to the target values in the case of the specimens according to Examples 1 to 3, EL): 20 to 30% and shock absorption energy at -60 캜: not less than 400 J were satisfied. In the case of the specimens according to Examples 1 to 3, the carbon equivalent (Ceq) corresponding to the target value was 0.40 or less and the welding crack susceptibility index (Pcm) was 0.23 or less.
On the other hand, the tensile strength (TS), yield strength (YS) and elongation (EL) of the specimen according to Comparative Example 1 satisfied the target value, but the impact absorption energy at -60 ° C was below the target value. In the case of the specimen according to Comparative Example 1, the weld crack susceptibility index (Pcm) satisfied the target value, but the carbon equivalent (Ceq) was below the target value.
In the specimens according to Comparative Examples 2 and 3, tensile strength, yield strength, and elongation were higher than the target values, but the impact absorption energy at -60 ° C was 68 J and 97 J, respectively Respectively. In the case of the specimens according to Comparative Examples 2 and 3, neither the carbon equivalent (Ceq) nor the weld crack susceptibility index (Pcm) satisfied the target value.
3 is a photograph showing the final microstructure of the specimen according to Example 1. Fig.
As shown in FIG. 3, in the case of the specimen according to Example 1, it can be seen that the final microstructure has a composite structure including acicular ferrite and bainite. As a result of measuring the fraction of the structure, it was confirmed that the acicular ferrite structure occupied 73.8% of the sectional area ratio.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Such changes and modifications are intended to fall within the scope of the present invention unless they depart from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.
S110: Slab reheating step
S120: Primary rolling step
S130: Secondary rolling step
S140: cooling step
Claims (8)
(b) primary rolling the reheated plate in an austenite recrystallization zone;
(c) secondarily rolling the primary rolled plate at a finishing rolling temperature (FRT) of 700 to 850 占 폚; And
(d) cooling the secondary rolled plate to a finishing cooling temperature (FCT) of 350 to 500 ° C.
In the step (a)
The slab plate
Wherein the steel sheet contains carbon (C), silicon (Si), manganese (Mn), copper (Cu), nickel (Ni) and chromium (Cr) in a range satisfying the following equations (1) Way.
[C] + [Mn / 6] + [(Cu + Ni) / 15] + [Cr / 5]
[C / 20] + [Ni / 60] + [Cr / 20] < / = 0.23
(Where [] is the weight percentage of each element)
In the step (d)
The cooling
Wherein the secondary rolled plate is cooled at an SCT (Start Cooling Temperature) of 700 to 800 占 폚.
In the step (d)
The cooling
At a rate of 3 to 7 占 폚 / sec.
Wherein the final microstructure has a composite structure including acicular ferrite and bainite, wherein the acicular ferrite structure has a cross-sectional area ratio of 70 to 80%.
The steel sheet
Wherein the steel sheet comprises carbon (C), silicon (Si), manganese (Mn), copper (Cu), nickel (Ni) and chromium (Cr) in a range satisfying the following equations (1) and (2).
[C] + [Mn / 6] + [(Cu + Ni) / 15] + [Cr / 5]
[C / 20] + [Ni / 60] + [Cr / 20] < / = 0.23
(Where [] is the weight percentage of each element)
The steel sheet
A tensile strength (TS) of 460 to 600 MPa, a yield strength of 350 to 500 MPa and an elongation (EL) of 20 to 30%.
The steel sheet
And an impact absorption energy at -60 DEG C: not less than 400J.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020130165569A KR20150076888A (en) | 2013-12-27 | 2013-12-27 | Extremely thick steel sheet and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020130165569A KR20150076888A (en) | 2013-12-27 | 2013-12-27 | Extremely thick steel sheet and method of manufacturing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20150076888A true KR20150076888A (en) | 2015-07-07 |
Family
ID=53789758
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020130165569A KR20150076888A (en) | 2013-12-27 | 2013-12-27 | Extremely thick steel sheet and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR20150076888A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180074228A (en) * | 2016-12-23 | 2018-07-03 | 주식회사 포스코 | High strength steel having excellent fracture initiation resistance and fracture arrestability in low temperature, and method for manufacturing the same |
| CN111945072A (en) * | 2020-08-26 | 2020-11-17 | 南京钢铁股份有限公司 | S460QLO thick plate for offshore weldable structure and production method |
-
2013
- 2013-12-27 KR KR1020130165569A patent/KR20150076888A/en not_active Application Discontinuation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20180074228A (en) * | 2016-12-23 | 2018-07-03 | 주식회사 포스코 | High strength steel having excellent fracture initiation resistance and fracture arrestability in low temperature, and method for manufacturing the same |
| EP3561123A4 (en) * | 2016-12-23 | 2019-10-30 | Posco | High-strength steel material having enhanced resistance to brittle crack propagation and break initiation at low temperature and method for manufacturing same |
| US11268175B2 (en) | 2016-12-23 | 2022-03-08 | Posco | High-strength steel having excellent fracture initiation resistance and fracture propagation arrestability at low temperature and method of manufacturing the same |
| CN111945072A (en) * | 2020-08-26 | 2020-11-17 | 南京钢铁股份有限公司 | S460QLO thick plate for offshore weldable structure and production method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2969200C (en) | Thick-walled high-toughness high-strength steel plate and method for manufacturing the same | |
| CN110088346B (en) | Steel material for welded steel pipe having excellent longitudinal uniform elongation, method for producing same, and steel pipe using same | |
| KR20150112489A (en) | Steel and method of manufacturing the same | |
| KR101467049B1 (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR20150076888A (en) | Extremely thick steel sheet and method of manufacturing the same | |
| KR101546132B1 (en) | Extremely thick steel sheet and method of manufacturing the same | |
| KR20140042101A (en) | Shape steel and method of manufacturing the same | |
| KR20140098901A (en) | Hot rolled steel sheet for steel pipe and method of manufacturing the steel pope | |
| KR20150124811A (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR20150002956A (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR101185222B1 (en) | Api hot-rolled steel sheet with high strength and method for manufacturing the api hot-rolled steel sheet | |
| KR101435319B1 (en) | Method of manufacturing steel sheet | |
| KR20150125142A (en) | Hot-rolled steel sheet and method of manufacturing the same | |
| KR101505290B1 (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR101400516B1 (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR20150112490A (en) | Steel and method of manufacturing the same | |
| KR101572353B1 (en) | Steel and method of manufacturing the same | |
| KR101546135B1 (en) | Extremely thick steel sheet and manufacturing method of the same | |
| KR101412372B1 (en) | Hot-rolled steel sheet and method of manufacturing the hot-rolled steel sheet | |
| KR101467048B1 (en) | Thick steel sheet and method of manufacturing the same | |
| KR101435318B1 (en) | Method of manufacturing wear resisting steel | |
| KR101455471B1 (en) | Steel sheet for line pipe and method of manufacturing the same | |
| KR101377890B1 (en) | High strength hot-rolled steel sheet and method of manufacturing the same | |
| KR101505278B1 (en) | Steel for cargo oil tank and method of manufacturing the same | |
| KR101505303B1 (en) | Steel sheet and method of manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E601 | Decision to refuse application |