WO2006009091A1 - 高温強度に優れた溶接構造用490MPa級高張力鋼ならびにその製造方法 - Google Patents
高温強度に優れた溶接構造用490MPa級高張力鋼ならびにその製造方法 Download PDFInfo
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- WO2006009091A1 WO2006009091A1 PCT/JP2005/013101 JP2005013101W WO2006009091A1 WO 2006009091 A1 WO2006009091 A1 WO 2006009091A1 JP 2005013101 W JP2005013101 W JP 2005013101W WO 2006009091 A1 WO2006009091 A1 WO 2006009091A1
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 84
- 239000010959 steel Substances 0.000 title claims abstract description 84
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 230000001747 exhibiting effect Effects 0.000 title abstract 2
- 239000000203 mixture Substances 0.000 claims abstract description 10
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 238000001816 cooling Methods 0.000 claims description 19
- 238000005096 rolling process Methods 0.000 claims description 19
- 229910001566 austenite Inorganic materials 0.000 claims description 15
- 238000005336 cracking Methods 0.000 claims description 5
- 230000009467 reduction Effects 0.000 claims description 5
- 238000003303 reheating Methods 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 230000001186 cumulative effect Effects 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 210000003462 vein Anatomy 0.000 claims description 2
- 239000004615 ingredient Substances 0.000 claims 1
- 229910052758 niobium Inorganic materials 0.000 abstract description 8
- 229910052719 titanium Inorganic materials 0.000 abstract description 8
- 229910001563 bainite Inorganic materials 0.000 abstract description 7
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 6
- 229910052720 vanadium Inorganic materials 0.000 abstract description 6
- 229910052804 chromium Inorganic materials 0.000 abstract description 3
- 229910052802 copper Inorganic materials 0.000 abstract description 3
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 abstract description 3
- 229910052791 calcium Inorganic materials 0.000 abstract description 2
- 229910052748 manganese Inorganic materials 0.000 abstract description 2
- 229910052761 rare earth metal Inorganic materials 0.000 abstract 1
- 230000035945 sensitivity Effects 0.000 abstract 1
- 239000000126 substance Substances 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 27
- 239000010953 base metal Substances 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 238000000576 coating method Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 238000005728 strengthening Methods 0.000 description 5
- 230000009466 transformation Effects 0.000 description 5
- 238000003466 welding Methods 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 239000006104 solid solution Substances 0.000 description 4
- 229910000746 Structural steel Inorganic materials 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 3
- 238000010276 construction Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000005098 hot rolling Methods 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000008520 organization Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241001201614 Prays Species 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000009970 fire resistant effect Effects 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000004881 precipitation hardening Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/002—Bainite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
Definitions
- the present invention is used for general welded structures such as buildings, civil engineering, offshore structures, shipbuilding, various storage tanks, etc., and in a temperature range of 600 ° C to 800 ° C, a relatively short time of about 1 hour.
- the present invention relates to a high-strength steel for welded structures with excellent high-temperature strength and a method for producing the same.
- the present invention mainly targets thick plates (thick steel plates), but also includes steel pipes and shaped steel. Background art
- the strength of general welded structural steel has been reduced from about 350 ° C, and its allowable temperature is about 500 ° C. For this reason, when these steel materials are used in buildings, offices, residences, multistory parking lots, and other buildings, it is obligatory to provide sufficient fireproof coatings to ensure safety in fires. According to the building-related laws and regulations, the steel temperature is 350 in the event of a fire. (: It is stipulated not to exceed the above. This is because the steel material has a yield strength of about 50 ° C and is about 23 to room temperature, which is below the required strength.) In fact, such a refractory coating has a great influence on construction costs.
- B is in the midst of merits and demerits, such as increasing hardenability. For example, during low heat input welding, the weld heat affected zone hardens significantly, resulting in poor toughness. Conversely, if the heat input is too high, it precipitates at the austenite grain boundaries and the hardenability of B cannot be used effectively. The problem was that the weld heat input range was limited due to the coarse structure and poor toughness.
- the present inventors are not limited to the definition of the yield ratio in ns steel for construction, not only high temperature strength but also weldability, The present inventors have intensively studied a steel material having excellent weld toughness in a wide heat input range, and have reached the present invention. Disclosure of the invention
- An object of the present invention is to provide a high-strength steel for welded structures excellent in high-temperature strength in a temperature range of 600 ° C. or higher and 800 ° C. or lower, and a manufacturing method capable of supplying the steel stably industrially. is there.
- the present invention achieves the object by limiting the steel components, microstructures, and the like to appropriate ranges, and the gist thereof is as follows.
- the microstructure is a mixed structure mainly of ferrite preparative base Inai DOO, 490MPa class high-strength steel for welded structures with excellent high-temperature strength, characterized by a 20-90% proportion of the vanite.
- the average equivalent circle diameter of the old austenite grains with a cross section parallel to the rolling direction at a thickness of 1 Z 4 is 120 m or less. 490MPa class high strength steel for welded structures with excellent high temperature strength as described.
- High-temperature strength is enhanced by the addition of Mo and Nb, which promotes stable carbonitride precipitation at high temperatures, increases the dislocation density by baiting the microstructure, and recovers dislocations by solid solution Mo and Nb. It is effective to delay.
- Mo and Nb which promotes stable carbonitride precipitation at high temperatures, increases the dislocation density by baiting the microstructure, and recovers dislocations by solid solution Mo and Nb. It is effective to delay.
- a large amount of Mo is indispensable in the extension of conventional knowledge, but excellent welding as a steel for welded structures. Contrary to the viewpoint of securing the weldability and weld toughness, it is extremely difficult to achieve high temperature strength.
- C has the most prominent effect on the properties of steel, and must be controlled within a narrow range, with a limited range of 0.005% or more and less than 0.040%. If the C content is less than 0.005%, the strength is insufficient, and if it exceeds 0.040%, the amount of Mo added is large. In the present invention, weldability and weld toughness are deteriorated, and the cooling rate after rolling is excessive. In this case, the risk of excess strength increases due to an increase in the yield of the bait. Furthermore, during high-temperature heating equivalent to a fire, the mixed matrix structure of bainite and Ferai ⁇ is kept thermodynamically stable, maintaining consistency with the composite carbonitride precipitates of Mo, Nb, V, and Ti. In order to secure the strengthening effect, C must be less than 0.040%.
- Si is an element contained in deoxidized upper steel and has a substitutional solid solution strengthening action, so it is effective in improving the strength of the base metal at room temperature, but particularly improves the high-temperature strength above 600 ° C. There is no effect.
- the upper limit was limited to 0.5%. Deoxidation of steel is possible with Ti and A1 alone, and is preferably as low as possible from the viewpoints of weld toughness and hardenability, and is not necessarily added.
- Mn is an indispensable element for ensuring strength and toughness, but Mn, a substitutional solid solution strengthening element, is effective in increasing the strength at room temperature, but particularly at high-temperature strength exceeding 600 ° C. Does not have a significant improvement effect. Therefore, the steel containing a relatively large amount of Mo as in the present invention needs to be less than 0.5% from the viewpoint of improving the weldability, that is, reducing the PCM.
- the upper limit of M n low, it is advantageous from the viewpoint of center segregation of the continuous forged slab.
- addition of 0.1% or more is necessary to adjust the strength and toughness of the base metal.
- P and S are impurities in the steel of the present invention, and the lower the better. P prays to the grain boundaries to promote grain boundary fracture, and S forms sulfides typified by MnS to degrade the toughness of the base metal and welds. % And 0.01%.
- Mo is an indispensable element along with Nb from the viewpoint of high temperature strength development and maintenance in the steel of the present invention. It is more advantageous to add more from the standpoint of high-temperature strength, but it should be constrained in consideration of the base metal strength, weldability, and weld toughness.
- Mo is allowed up to 5% 1.
- the lower limit is the combined addition with N1) or the addition of V and Ti, which are effective for improving the high-temperature strength described later, ensuring stable high-temperature strength. In order to achieve this, it is necessary to add 0.3% or more.
- Nb is an element that must be added in combination with Mo.
- Nb is an element useful for raising the recrystallization temperature of austenite and maximizing the effect of controlled rolling during hot rolling. It also contributes to the fine graining of the heating austenite during reheating prior to rolling. In addition, it has the effect of improving high-temperature strength by strengthening precipitation and suppressing dislocation recovery, and by adding it together with Mo, it contributes to further enhancement of high strength. If it is less than 0.03%, the effect of suppressing precipitation hardening and dislocation recovery at 700 ° C and 800 ° C is small, and if it exceeds 0.15%, the degree of hardening decreases with respect to the added amount, which is not economically undesirable. The toughness of the weld also deteriorates. For these reasons, Nb is limited to the range of 0.03 to 0.15%.
- A1 is an element generally contained in steel for deoxidation, but Si or Ti is sufficient for deoxidation, and in the present invention, the lower limit is not limited (including 0%). However, increasing the amount of A1 not only deteriorates the cleanliness of the steel, but also deteriorates the toughness of the weld. Therefore, the upper limit was set to 0.06%.
- N is contained in steel as an inevitable impurity.
- Nb and Ti described later are added, Nb combines with Nb to form carbonitride to increase the strength or TiN.
- a minimum N content of 0.001% is necessary.
- an increase in the amount of N is harmful to weld toughness and weldability, and in the present invention, the upper limit is 0.006%.
- This upper limit is not necessarily limited in terms of characteristics, and is limited within the range confirmed by the present inventors.
- Cu, Ni, Cr that can be contained as necessary The reasons for the addition of Ca, V, Ti, Ca, REM, and Mg and the range of the amount added will be explained.
- the main purpose of adding these elements to the basic components is This is because the characteristics such as strength and toughness are improved without impairing the excellent characteristics of the steel of the present invention. Therefore, the amount of addition is of a nature that should be restricted naturally.
- Cu improves the strength and toughness of the base metal without significantly affecting the weldability and weld toughness. In order to exert these effects, addition of at least 0.05% is essential. On the other hand, excessive addition leads to a deterioration of weldability and also increases the risk of Cu cracking during hot rolling, so the upper limit was limited to 1.0%. It is known that the crack itself can be avoided by the proper addition of Ni depending on the amount of Cu, and because the weldability is also related to the amount of other alloy elements including the amount of C, the upper limit is not necessarily limited. It does not have an implication.
- Ni exhibits almost the same effect as Cu, and has a particularly large effect on improving the toughness of the base metal. In order to reliably enjoy these effects, at least 0.05% addition is essential. On the other hand, excessive addition of Ni degrades weldability and is a relatively expensive element, and also impairs economics. Therefore, in the present invention, 490MPa class steel is used in the evening. Considering that it is a get, the upper limit is 1.0%.
- Cr can be added as necessary to improve the strength of the base material. It can be clearly distinguished from the small amount of soot lamps from scraps, etc., and it is necessary to add 0.05% or more at least in order to enjoy the effect reliably. Too much addition, like other elements, degrades weldability and weld toughness, so the upper limit is limited to 1.0%.
- Cu, Ni, and Cr are effective not only in terms of mechanical properties of the base metal but also in weather resistance. For such purposes, weldability and weld toughness are greatly impaired. It is preferable to add it as much as possible.
- V has almost the same effect and action as Nb, including improved high-temperature strength. However, the effect is small compared to Nb. In addition, V has an effect on hardenability and weldability, as can be seen from the PeM equation. Therefore, the lower limit is set to 0.01% to ensure the effect of V addition, and the upper limit is set to 0.1% to eliminate adverse effects.
- Ti like Nb and V, is effective in improving high temperature strength. In addition to this, it is preferable to add them particularly when the requirements for the base metal and the weld zone toughness are severe. Because, Ti, when the amount of A1 is small (e.g., 0.003% or less), forming a deposit composed mainly of Ti 2 0 3 combine with ⁇ , becomes intragranular ferrite formation of nuclei, the weld toughness Improve. In addition, Ti combines with N and precipitates finely in the slab as TiN, which suppresses the coarsening of austenite grains during heating and is effective in refining the rolling structure. The fine TiN present in the steel sheet ⁇ Refine the grain structure of the heat affected zone during welding. To obtain these effects, Ti must be at least 0.005%. However, if it is too much, TiC is formed and low temperature toughness deteriorates weldability, so the upper limit is 0.025%.
- Ca and REM combine with S, an impurity, to improve toughness and suppress cracks due to diffusible hydrogen in the weld.
- S an impurity
- coarse inclusions are formed, which adversely affects toughness. Therefore, both are limited to the range of 0.0005 to 0.004%. Since both elements have almost the same effect, at least one of them should be added in order to enjoy the above-described effect.
- Mg has the effect of suppressing the growth of austenite grains in the weld heat-affected zone and making it finer, making it possible to strengthen the weld zone. In order to enjoy such effects, Mg needs to be 0.0001% ⁇ . On the other hand, as the added amount increases, the effect on the added amount decreases and the economy is lost, so the upper limit was set to 0.006%.
- B is not made intentionally, and steelmaking The point is that it does not contain substantially beyond the level included as a contamination in the process.
- B is extremely advantageous in terms of microstructure control and strength improvement when used in high-strength steel because B significantly increases hardenability, but it also has the risk of degrading weldability and weld toughness. Have both.
- the present invention avoids the intentional addition of B and makes it substantially B-free for the purpose of further improving the use performance as a welded structural steel in addition to the high temperature characteristics.
- P CM C + Si / 30 + Mn / 20 + Cu / 20 + Ni / 60 + Cr / 20 + Mo / 15+ V / 10+ 5 B
- P CM is that 0.15% or less, very low It is.
- the microstructure is also limited.
- the steel components By limiting the steel components only, excellent weldability and weld toughness as welded structural steel can be secured, but high temperature characteristics and above all basic characteristics (particularly strength) as 490 MPa class steel cannot be satisfied. .
- the microstructure is mainly composed of a mixture of ferrite and bainite, and the fraction of the paynai is limited to 20 to 90%.
- the austenite grain size before transformation after rolling needs to be appropriately limited in order to control (toughen) the toughness of a relatively high Mo-added steel such as the present invention.
- the finer the austenite the finer the final transformation structure and the better the toughness.
- the austenite grain size at the 1/4 thickness position in the final thickness direction of the steel sheet is limited to an average equivalent circle diameter of 120 ⁇ m or less.
- the austenite particle size In many cases, it is not always easy to distinguish the austenite particle size. In such a case, use an impact test piece with a notch sampled in the direction perpendicular to the final rolling direction of the steel sheet, centering on the position where the plate thickness is 1/4 thickness, for example, JISZ 2202 2mmV notch test piece, etc.
- the fracture surface unit is defined as the effective crystal grain size that can be read as an austenite grain size, and the average equivalent circle diameter is to be measured. In this case as well, it must be 120 xm or less. .
- the excellent properties aimed at by the present invention including the structure as described above (structure, tissue fraction, former austenite particle size, etc.) and high-temperature properties, are as follows. It can be easily obtained.
- the reheating of billets or slabs with a given steel composition is limited to a temperature range of 1 100-1250 ° C.
- the lower limit of 1 100 ° C is to make Mo, Nb, and V and Ti added as needed, in a solid solution state with the primary purpose of ensuring high-temperature properties.
- the higher the reheating temperature the better.
- the heating austenite grains become coarse, which is not preferable from the viewpoint of the base metal toughness, so the upper limit is limited to 1250 ° C.
- the limitation of the rolling conditions is to directly control the austenite grain size before transformation after rolling to a relatively fine grain as described above, mainly for ensuring toughness. For this reason, rolling requires that the cumulative reduction at 1 100 ° C or less be 30% or more.
- the rolling end temperature is limited to 850 ° C or more as the lower limit temperature for precipitation of Mo, Nb, or V and Ti added as needed, as carbides, under low temperature pressure.
- Cooling after rolling should also be limited from the viewpoint of structure control. Although it depends on the steel composition, a relatively thin material can obtain a specified structure even at a cooling rate that is about the same as that of cooling. However, if it is thicker, the cooling rate becomes slower when cooling is needed, and accelerated cooling is required. There is. In this case, accelerated cooling is most commonly water cooling in the production of thick steel sheets, but it is not always necessary to use water cooling. In addition, accelerated cooling is aimed at increasing the cooling speed in the transformation region for the purpose of controlling the structure, so it is necessary to perform from 800 ° C to 650 ° C.
- the comparative example is inferior in characteristics to the inventive example because at least one of the steel components, production conditions, and structure deviates from the limited range of the present invention. I understand. That is, in Comparative Example 19, the amount of C is low, and thus the fraction of the vein is low, and both the room temperature strength and the high temperature strength (ratio) are low. In Comparative Example 20, the amount of C is high, so the bainitic fraction is high, and the room temperature strength is high. In addition, the base metal toughness, reproducible HAZ toughness is also inferior.
- Comparative Example 21 the Mo amount is low and the accelerated cooling start temperature is low, so the high-temperature strength (ratio) is low due to the low payin fraction.
- Comparative Example 22 the Nb content is low, the heating temperature and the rolling end temperature are low, and the accelerated cooling stop temperature is high, so the normal temperature strength and high temperature strength (ratio) are low.
- Comparative Example 23 since B is added, when accelerated cooling is applied, the bainite fraction is high and the base material toughness is poor. In addition, the reproducible HAZ toughness is inferior.
- Comparative Example 24 has a high amount of Mn, P CM In addition to being high, the cumulative reduction at 1100 ° C or lower is also low, so the strength of the base metal becomes excessive as 490MPa grade steel due to the high bainitic fraction, and the base metal toughness and reproducible HAZ toughness are also poor.
- Tensile test piece Thickness 40mm or less JIS Z 2201 1A (full thickness), Thickness over 5Qmni JIS Z 2201 No. 4
- Charpy impact test piece JIS Z 2202 2miiV notch, rolling direction
- High-temperature tensile specimen Round bar (8mii or ⁇ ), 1/4 thickness position, perpendicular to rolling direction
- Thermal history 1 1400 ° C x 1 second, 800 ⁇ 500 cooling time 8 seconds
- the steel materials manufactured by the steel components and the manufacturing method based on the present invention have been demonstrated in the examples that the microstructure also satisfies the limited range of the present invention and is excellent not only in high temperature strength but also in weldability and weld toughness. .
- welded structural steels with high-temperature properties far exceeding conventional refractory steels that guarantee high-temperature properties up to about 600 ° C can be industrially produced in large quantities. Large expansion of buildings and complete fireproof coating is expected.
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- Mechanical Engineering (AREA)
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Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05760159A EP1790749A1 (en) | 2004-07-21 | 2005-07-08 | 490 MPa GRADE HIGH TENSILE STEEL FOR WELDED STRUCTURE EXHIBITING EXCELLENT HIGH TEMPERATURE STRENGTH AND METHOD FOR PRODUCTION THEREOF |
US11/215,413 US20060016526A1 (en) | 2004-07-21 | 2005-08-29 | High-strength steel for welded structures excellent in high temperature strength and method of production of the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2004213511A JP4864297B2 (ja) | 2004-07-21 | 2004-07-21 | 高温強度に優れた溶接構造用490MPa級高張力鋼ならびにその製造方法 |
JP2004-213511 | 2004-07-21 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US11/215,413 Continuation-In-Part US20060016526A1 (en) | 2004-07-21 | 2005-08-29 | High-strength steel for welded structures excellent in high temperature strength and method of production of the same |
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WO2006009091A1 true WO2006009091A1 (ja) | 2006-01-26 |
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PCT/JP2005/013101 WO2006009091A1 (ja) | 2004-07-21 | 2005-07-08 | 高温強度に優れた溶接構造用490MPa級高張力鋼ならびにその製造方法 |
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US (1) | US20060016526A1 (ja) |
EP (1) | EP1790749A1 (ja) |
JP (1) | JP4864297B2 (ja) |
CN (1) | CN1989264A (ja) |
TW (1) | TWI297732B (ja) |
WO (1) | WO2006009091A1 (ja) |
Cited By (1)
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US8123986B2 (en) * | 2006-06-29 | 2012-02-28 | Lg Electronics Inc. | Paste, method of manufacturing plasma display panel using the paste and plasma display apparatus |
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JP4673822B2 (ja) * | 2006-11-14 | 2011-04-20 | 新日本製鐵株式会社 | 溶接継手部の靱性に優れた耐火鋼材及びその製造方法 |
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DE102007061084A1 (de) * | 2007-12-19 | 2009-07-02 | Federal-Mogul Sealing Systems Gmbh | Metallische Flachdichtung und Herstellverfahren |
CN101613840B (zh) * | 2008-06-23 | 2011-03-30 | 宝山钢铁股份有限公司 | 强韧性匹配及高温性能优良的特厚钢板及其制造方法 |
JP5743382B2 (ja) * | 2009-03-19 | 2015-07-01 | Jfeスチール株式会社 | 耐震性構造物用鋼材及びその製造方法 |
KR101130013B1 (ko) * | 2009-03-26 | 2012-03-26 | 현대제철 주식회사 | 고장력 열연강판 및 그 제조방법 |
US20110186182A1 (en) * | 2009-05-15 | 2011-08-04 | Tetsushi Chida | Steel for nitrocarburizing and nitrocarburized parts |
CN101775561B (zh) * | 2010-03-19 | 2012-07-11 | 江苏省沙钢钢铁研究院有限公司 | 低屈强比高强度厚板及其制备工艺 |
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WO2014143702A2 (en) * | 2013-03-15 | 2014-09-18 | Am/Ns Calvert Llc | Line pipe steels and process of manufacturing |
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CN107190203B (zh) * | 2017-05-31 | 2019-07-23 | 武汉钢铁有限公司 | 用薄板坯直接轧制的屈服强度≥800MPa热轧薄板及生产方法 |
CN109487153B (zh) * | 2017-09-11 | 2021-01-08 | 上海梅山钢铁股份有限公司 | 一种抗拉强度440MPa级高扩孔热轧酸洗钢板 |
CN110129539B (zh) * | 2019-05-31 | 2021-03-23 | 东北大学 | 一种500MPa级海洋工程用H型钢的生产工艺 |
CN110699594B (zh) * | 2019-10-30 | 2021-06-04 | 攀钢集团攀枝花钢铁研究院有限公司 | 半钢低成本冶炼if钢的方法 |
CN112746158A (zh) * | 2019-12-30 | 2021-05-04 | 宝钢湛江钢铁有限公司 | 低成本、高止裂及高焊接性YP460MPa级厚钢板及其制造方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05171265A (ja) * | 1991-12-20 | 1993-07-09 | Sumitomo Metal Ind Ltd | 高温強度特性に優れる鉄骨建築用高耐候性鋼材の製造方法 |
JP2004043961A (ja) * | 2002-05-20 | 2004-02-12 | Nippon Steel Corp | 高温強度に優れた490MPa級高張力鋼ならびにその製造方法 |
JP7056044B2 (ja) * | 2017-09-11 | 2022-04-19 | コニカミノルタ株式会社 | 用紙処理装置、画像形成システム及びプログラム |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3417878B2 (ja) * | 1999-07-02 | 2003-06-16 | 株式会社神戸製鋼所 | 伸びフランジ性および疲労特性に優れた高強度熱延鋼板およびその製法 |
CN101082105A (zh) * | 2002-03-29 | 2007-12-05 | 新日本制铁株式会社 | 高温强度优异的高强度钢及其制造方法 |
-
2004
- 2004-07-21 JP JP2004213511A patent/JP4864297B2/ja not_active Expired - Fee Related
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2005
- 2005-07-08 EP EP05760159A patent/EP1790749A1/en not_active Withdrawn
- 2005-07-08 CN CNA2005800242067A patent/CN1989264A/zh active Pending
- 2005-07-08 WO PCT/JP2005/013101 patent/WO2006009091A1/ja active Application Filing
- 2005-07-20 TW TW094124502A patent/TWI297732B/zh not_active IP Right Cessation
- 2005-08-29 US US11/215,413 patent/US20060016526A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH05171265A (ja) * | 1991-12-20 | 1993-07-09 | Sumitomo Metal Ind Ltd | 高温強度特性に優れる鉄骨建築用高耐候性鋼材の製造方法 |
JP2004043961A (ja) * | 2002-05-20 | 2004-02-12 | Nippon Steel Corp | 高温強度に優れた490MPa級高張力鋼ならびにその製造方法 |
JP7056044B2 (ja) * | 2017-09-11 | 2022-04-19 | コニカミノルタ株式会社 | 用紙処理装置、画像形成システム及びプログラム |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8123986B2 (en) * | 2006-06-29 | 2012-02-28 | Lg Electronics Inc. | Paste, method of manufacturing plasma display panel using the paste and plasma display apparatus |
Also Published As
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US20060016526A1 (en) | 2006-01-26 |
TWI297732B (en) | 2008-06-11 |
EP1790749A1 (en) | 2007-05-30 |
JP2006028628A (ja) | 2006-02-02 |
JP4864297B2 (ja) | 2012-02-01 |
CN1989264A (zh) | 2007-06-27 |
TW200606260A (en) | 2006-02-16 |
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