WO2012115280A1 - 耐候性に優れた構造用鋼材 - Google Patents

耐候性に優れた構造用鋼材 Download PDF

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WO2012115280A1
WO2012115280A1 PCT/JP2012/055297 JP2012055297W WO2012115280A1 WO 2012115280 A1 WO2012115280 A1 WO 2012115280A1 JP 2012055297 W JP2012055297 W JP 2012055297W WO 2012115280 A1 WO2012115280 A1 WO 2012115280A1
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weather resistance
steel
value
steel material
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French (fr)
Japanese (ja)
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進一 三浦
勇 鹿毛
村瀬　正次
星野　俊幸
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Ｊｆｅスチール株式会社
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Priority to KR1020137023586A priority Critical patent/KR20130123431A/ko
Priority to CN201280010266.3A priority patent/CN103392023B/zh
Priority to KR1020157014711A priority patent/KR20150067771A/ko
Publication of WO2012115280A1 publication Critical patent/WO2012115280A1/ja

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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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur

Definitions

  • the present invention relates to steel structures mainly used outdoors such as bridges (Steel Structures), and in particular, in a high-air salinity environment such as coastal environment (air-borne salt) (
  • the present invention relates to a steel material suitable as a member that requires an atmospheric corrosion resistance.
  • weathering steel has been used.
  • Weatherproof steel is corrosion-induced by covering the surface with a highly protective rust layer enriched with alloy elements such as Cu, P, Cr, Ni, etc. in an atmosphere exposure environment (atmospheric environment). rate) is a steel material with a significant reduction. Due to its excellent weather resistance, it is known that bridges using weather resistant steel often withstand service for decades while still being paintless.
  • the amount of flying salt is a value measured by the method of JIS Z2382.
  • conventional weathering steel JIS G 3114: weathering hot rolled steel for welded structure
  • unit (mg (NaCl / dm 2 / day) may be expressed in mdd) Only in the following areas, it can be used without painting.
  • Patent Document 1 discloses a highly weather-resistant steel material to which Cu and 1% by mass or more of Ni are added as a weather resistance improving element.
  • Patent Document 2 discloses a steel material excellent in weather resistance to which 1% by mass or more of Ni and Mo are added.
  • Patent Document 3 the steel material excellent in the weather resistance which added Cu and Ti in addition to Ni is disclosed.
  • Patent Document 4 discloses a steel material for welded structure containing a large amount of Ni and additionally containing Cu, Mo, Sn, Sb, P and the like.
  • Patent Document 5 discloses a marine corrosion resistant steel material containing W and Cr and additionally containing Sb, Sn, Ni, and the like.
  • Japanese Patent No. 3785271 Japanese Patent Laid-Open No. 11-172370
  • Japanese Patent No. 3846218 Japanese Patent Laid-Open No. 2002-309340
  • Japanese Patent No. 3568760 Japanese Patent Laid-Open No. 11-71632
  • Patent Documents 1 and 2 when the Ni content is increased, there is a problem that the price of the steel material increases due to an increase in alloy cost. Further, in Patent Document 3, since Ti is an essential element, the toughness may deteriorate when a large amount of Ti is added. Further, as in Patent Document 4, in steel materials that increase the Ni content and contain Cu, Mo, Sn, Sb, P, etc., the price of the steel materials increases due to an increase in alloy costs, and further, the inclusion of P Due to the high amount, weldability decreases.
  • Patent Document 5 because the steel materials disclosed in Patent Document 5 have different uses, the environments to which the steel materials are exposed are also greatly different, and as a result, the required corrosion resistance is different, and the weather resistance in a high-flying salinity environment such as near the coast is described. Not.
  • an object of the present invention is to provide a structural steel material that is low in cost and excellent in weather resistance even in an environment where the amount of incoming salt is about 0.4 mdd.
  • the component composition of steel materials has been intensively studied from the viewpoint of weather resistance in an environment with high flying salt content.
  • the weather resistance of the steel material in an environment with high flying salinity is improved by compositely containing W and Sn and / or Nb in the base steel containing Cu and Ni.
  • the steel sheet thickness reduction (84 days) due to corrosion in the wet and dry cyclic corrosion test described later (84 days) is the steel sheet due to corrosion when exposed to an actual environment with an incoming salt content of about 0.4 mdd for 84 days. It has been found to be equivalent to the thickness reduction. Therefore, in the present invention, the wet and dry repeated corrosion test described later was conducted as a method for evaluating the weather resistance in an environment where the amount of salt in the air is about 0.4 mdd. Conventionally, the steel types No. 1 shown in Table 1 below, which contain a large amount of Ni, are used. No.
  • steel containing W and Nb in combination, or steel containing W and Sn in combination are subjected to a corrosion test in comparison with conventional weather resistant steel, ordinary steel, and weather resistant steel using a combination of other elements.
  • the steel plate thickness reduction amount becomes a small value, and the weather resistance tends to be excellent, and the composition in which the component content in the steel is more limited and adjusted, even when compared with the steel type with a high Ni content, the weather resistance is more Excellent results were obtained.
  • the reason why the weather resistance was excellent despite the low Ni content is estimated as follows. That is, Cu and Ni densify the rust layer, and prevent chloride ions, which are corrosion promoting factors, from passing through the rust layer and reaching the ground iron. W forms a complex oxide of Fe in the vicinity of the interface between the rust layer and the ground iron in the anode portion, and suppresses the anode reaction. In addition, by being distributed in the rust layer as W acid ions, cation selective permeability is exhibited, and chloride ions, which are corrosion promoting factors, are prevented from passing through the rust layer and reaching the base iron.
  • Nb is concentrated near the interface between the rust layer and the ground iron in the anode part to suppress the anode reaction and the cathode reaction.
  • Sn is concentrated near the interface between the rust layer and the ground iron in the anode part to suppress the anode reaction and the cathode reaction.
  • these effects are not sufficient when contained alone, and the corrosion inhibition effect of Cu, Ni, W, Nb, Sn is greatly improved by the synergistic effect of the combined inclusion of Cu, Ni, W and Nb and / or Sn. .
  • the weather resistance is superior to that of a steel type containing Ni alone in a high content.
  • the present inventors have further conducted intensive studies on the influence of these elements on the weather resistance, and found the weather resistance index R value shown below. And it discovered that the steel material excellent in weather resistance can be obtained by adjusting the component content in steel of Cu, Ni, W, Nb, and Sn so that this R value may be 2.0 or more. It was.
  • R value ⁇ 2.0 mass%
  • R value (R1 value + R2 value) 0.5
  • R1 value [Cu] ⁇ 0.2 + [Ni] ⁇ 3 + [W] ⁇ 4 + [Nb] ⁇ 20 + [Sn] ⁇ 8.5
  • R2 value (Log 1.5 ([W] 2 +0.002) +16) ⁇ ((Log 2 ([Nb] ⁇ 0.1 + 0.001) +10) + (Log 2 ([Sn] ⁇ 0.1 + 0. 001) +10) ⁇ 0.75) ⁇ 0.5
  • [M] shows content (mass%) of the element M, and is set to 0 when not containing.
  • R1 value was created semi-empirically by estimating the effects of each component alone that contributes to improving the weather resistance from the various tests described above.
  • R2 value is trying to evaluate the synergistic effect of each component. Since the synergistic effect tends to saturate gradually with respect to the added amount, it is considered that it is expressed by a logarithmic function, and the constant is set semi-empirically.
  • the improvement effect on the weather resistance was considered as the sum of the single effect and the synergistic effect, and an equation representing the R value of the present invention was derived.
  • a structural steel material excellent in weather resistance characterized by containing one or two types of 200% or less, the balance being iron and inevitable impurities, and satisfying the following formula (1).
  • R value ⁇ 2.0 mass% Formula (1)
  • R value (R1 value + R2 value) 0.5
  • R1 value [Cu] ⁇ 0.2 + [Ni] ⁇ 3 + [W] ⁇ 4 + [Nb] ⁇ 20 + [Sn] ⁇ 8.5
  • R2 value (Log 1.5 ([W] 2 +0.002) +16) ⁇ ((Log 2 ([Nb] ⁇ 0.1 + 0.001) +10) + (Log 2 ([Sn] ⁇ 0.1 + 0. 001) +10) ⁇ 0.75) ⁇ 0.5
  • [M] shows content (mass%) of the element M, and is set to 0 when not containing.
  • [2] A structural steel material excellent in weather resistance according to [1], further comprising Cr: more than 0.1% and 1.0% or less in mass%. [3] In the above [1] or [2], further, by mass, Co: 0.01% to 1.00%, Mo: 0.005% to 1.000%, Sb: 0.005 A structural steel material having excellent weather resistance, comprising at least one selected from% to 0.200% and REM: 0.0001% to 0.1000%.
  • structural steel material excellent in weather resistance is a structural steel material that practically satisfies the high weather resistance applicable in a high flying salinity environment of 0.4 mdd or less.
  • a structural steel material having a low cost and excellent weather resistance can be obtained.
  • the structural steel material of the present invention has a practical weldability at a low cost without containing a large amount of an expensive element such as Ni by containing a combination of elements effective for improving weather resistance, It can have excellent weather resistance in an environment with a large amount of incoming salt, such as in the vicinity. In particular, it has a remarkable effect in a high flying salt environment where the flying salt amount exceeds 0.05 mdd.
  • the upper limit of the amount of incoming salt is preferably 0.4 mdd or less.
  • C 0.020% or more and less than 0.140%
  • C is an element that improves the strength of the structural steel material, and it is necessary to contain 0.020% or more in order to ensure a predetermined strength.
  • the C content is 0.020% or more and less than 0.140%.
  • it is 0.060% or more and 0.100% or less.
  • Si 0.05% or more and 2.00% or less Si should be contained in an amount of 0.05% or more as a deoxidizer during steelmaking and as an element for improving the strength of the structural steel material and ensuring a predetermined strength. is there. On the other hand, if it exceeds 2.00% and it contains excessively, toughness and weldability will deteriorate remarkably. Therefore, the Si content is 0.05% or more and 2.00% or less. Preferably, it is 0.10% or more and 0.80% or less.
  • Mn 0.20% or more and 2.00% or less
  • Mn is an element that improves the strength of the structural steel material, and it is necessary to contain 0.20% or more in order to ensure a predetermined strength.
  • the Mn content is 0.20% or more and 2.00% or less.
  • it is 0.20% or more and 1.50% or less.
  • P 0.005% or more and 0.030% or less
  • P is an element that improves the weather resistance of the structural steel. In order to acquire such an effect, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 0.030%, weldability deteriorates. Therefore, the P content is 0.005% or more and 0.030% or less. Preferably, it is 0.005% or more and 0.025% or less.
  • the S content is set to be 0.0001% or more and 0.0200% or less. Preferably, it is 0.0003% or more and 0.0050% or less.
  • Al 0.001% or more and 0.100% or less
  • Al content is set to be 0.001% or more and 0.100% or less. Preferably, it is 0.010% or more and 0.050% or less.
  • Al content measures acid-soluble Al.
  • Cu 0.10% or more and 1.00% or less Cu has an effect of forming a dense rust layer by refining rust grains and improving the weather resistance of the structural steel material. Such an effect is obtained when the content is 0.10% or more. On the other hand, if it exceeds 1.00%, the cost increases with an increase in the amount of Cu added. Therefore, the Cu content is set to 0.10% or more and 1.00% or less. Preferably, it is 0.20% or more and 0.50% or less.
  • Patent Document 5 relates to a marine corrosion resistant steel material.
  • the corrosion-resistant steel material for marine vessels described in Patent Document 5 exhibits excellent corrosion resistance without being affected by the surface condition of the steel material in a severe corrosive environment that is directly affected by seawater or its splashes, such as a ship's ballast tank.
  • the purpose is to reduce the work of repair painting.
  • the structural steel material of the present invention is applicable to steel structures used outdoors such as bridges, and can be used in a high-flying salinity environment of about 0.4 mdd, such as near the coast, without painting.
  • Patent Document 5 The purpose and the steel material described in Patent Document 5 are greatly different from the environment and purpose of using the steel material. Therefore, although it is not necessary to contain Cu in the steel material of patent document 5, in this invention, it is necessary to contain Cu, to form a dense rust layer, and to improve the weather resistance of steel materials. Therefore, as above-mentioned, in this invention, Cu shall contain 0.10% or more.
  • Ni 0.10% or more and less than 0.65%
  • Ni has an effect of forming a dense rust layer by refining rust grains and improving the weather resistance of the structural steel material. In order to obtain this effect sufficiently, it is necessary to contain 0.10% or more. On the other hand, if it is 0.65% or more, an increase in Ni consumption will be caused. Therefore, the Ni content is 0.10% or more and less than 0.65%. Preferably, it is 0.15% or more and 0.50% or less.
  • W 0.05% to 1.00%
  • Nb 0.005% to 0.200%
  • / or Sn 0.005% to 0.200% W
  • W is an important requirement in the present invention.
  • Nb 0.005% to 0.200%
  • Sn 0.005% to 0.200%
  • W is an important requirement in the present invention.
  • WO 4 2 ⁇ is eluted with the anode reaction of the steel material and distributed as WO 4 2 ⁇ in the rust layer, so that chloride ions of the corrosion promoting factor permeate the rust layer and reach the ground iron. Is electrostatically prevented.
  • the precipitation of a compound containing W on the steel material surface suppresses the anode reaction of the steel material.
  • the W content is 0.05% or more and 1.00% or less.
  • it is 0.10% or more and 0.70% or less.
  • Nb is an important requirement in the present invention.
  • Nb By coexisting with W, Nb has an effect of remarkably improving the weather resistance of the steel material in a high flying salinity environment.
  • the anode portion is concentrated near the interface between the rust layer and the ground iron to suppress the anode reaction and the cathode reaction.
  • Nb needs to be contained in an amount of 0.005% or more.
  • the toughness is reduced. Therefore, the Nb content is 0.005% or more and 0.200% or less.
  • it is 0.010% or more and 0.050% or less.
  • Sn is an important requirement in the present invention, and coexisting with W has an effect of remarkably improving the weather resistance of the steel material in a high flying salinity environment. Moreover, the weather resistance of structural steel materials is improved by forming an oxide film containing Sn on the steel material surface and suppressing the anode reaction and cathode reaction of the steel materials. In order to obtain these effects sufficiently, it is necessary to contain Sn by 0.005% or more. On the other hand, if it exceeds 0.200%, the ductility and toughness of the steel are deteriorated. Therefore, the Sn content is set to be 0.005% or more and 0.200% or less. Preferably, it is 0.010% or more and 0.050% or less.
  • the effect of this invention can be show
  • Nb and Sn contain at least any 1 type.
  • both Nb and Sn are contained, there is an effect of improving the weather resistance more remarkably.
  • the reason for the effect of containing both Nb and Sn is not clear, but in an environment where the drying process and the wetting process are repeated, conditions under which Nb and Sn exhibit a remarkable effect (for example, temperature, relative humidity, or rust) It is considered that Nb and Sn have improved weather resistance more remarkably by complementing their respective effects because the environment (such as the salinity of the salt) is different.
  • Nb and Sn are added amounts of Nb and Sn without deteriorating the weather resistance.
  • containing both Nb and Sn is a preferred invention form.
  • the balance is Fe and inevitable impurities.
  • N 0.010% or less
  • O 0.010% or less
  • Ca 0.0010% or less are acceptable as inevitable impurities.
  • Ca contained as an unavoidable impurity is present in a large amount in steel, the toughness of the weld heat affected zone is deteriorated, so 0.0010% or less is preferable.
  • Cr 0.1% to 1.0% or less
  • Cr is an element that forms a dense rust layer by refining rust grains and improves weather resistance. In order to sufficiently obtain this effect, It is necessary to contain it exceeding 0.1%. On the other hand, if it exceeds 1.0%, the weldability is lowered. Therefore, when it contains, Cr content exceeds 0.1% and 1.0% or less, Preferably, it is 0.2% or more and 0.7% or less.
  • Co 0.01% or more and 1.00% or less
  • Co is distributed throughout the rust layer, and by forming fine rust layers by refining rust grains, it has an effect of improving the weather resistance of the structural steel material. In order to sufficiently obtain such an effect, it is necessary to contain 0.01% or more. On the other hand, if it exceeds 1.00%, the cost increases with the increase in Co consumption. Therefore, when it is contained, the Co content is 0.01% or more and 1.00% or less, preferably 0.10% or more and 0.50% or less.
  • Mo 0.005% or more and 1.000% or less
  • Mo is a corrosion-promoting factor chloride because MoO 4 2 ⁇ is eluted with the anode reaction of the steel material and MoO 4 2 ⁇ is distributed in the rust layer. It prevents ions from penetrating the rust layer and reaching the ground iron. Moreover, the anode reaction of steel materials is suppressed because the compound containing Mo precipitates on the steel material surface. In order to obtain these effects sufficiently, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 1.000%, the cost will increase with the increase in Mo consumption. Therefore, when contained, the Mo content is 0.005% or more and 1.000% or less, preferably 0.100% or more and 0.500% or less.
  • Sb 0.005% or more and 0.200% or less
  • Sb is an element that suppresses the anode reaction of the steel material and improves the weather resistance of the structural steel material by suppressing the hydrogen generation reaction that is a cathode reaction. In order to obtain such effects sufficiently, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 0.200%, the toughness is deteriorated. Therefore, when it contains, Sb content is 0.005% or more and 0.200% or less, Preferably, it is 0.020% or more and 0.060% or less.
  • REM 0.0001% or more and 0.1000% or less REM is distributed throughout the rust layer, and by forming fine rust layers by refining rust grains, it has the effect of improving the weather resistance of structural steel materials. In order to obtain this effect sufficiently, it is necessary to contain 0.0001% or more. On the other hand, if it exceeds 0.1000%, the effect is saturated. Therefore, when it contains, REM content is 0.0001% or more and 0.1000% or less, Preferably, it is 0.0010% or more and 0.0350% or less.
  • Ti 0.005% or more and 0.200% or less
  • Ti is an element necessary for increasing the strength. In order to obtain this effect sufficiently, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 0.200%, the toughness is deteriorated. Therefore, when Ti is contained, the Ti content is 0.005% or more and 0.200% or less, preferably 0.010% or more and 0.100% or less.
  • V 0.005% or more and 0.200% or less
  • V is an element necessary for increasing the strength. In order to obtain this effect sufficiently, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 0.200%, the effect is saturated. Therefore, when it contains, V content is 0.005% or more and 0.200% or less, Preferably, it is 0.010% or more and 0.100% or less.
  • Zr 0.005% or more and 0.200% or less
  • Zr is an element necessary for increasing the strength. In order to obtain this effect sufficiently, it is necessary to contain 0.005% or more. On the other hand, if it exceeds 0.200%, the effect is saturated. Therefore, when contained, the Zr content is 0.005% or more and 0.200% or less, preferably 0.010% or more and 0.100% or less.
  • B 0.0001% or more and 0.0050% or less B is an element necessary for increasing the strength. In order to obtain this effect sufficiently, it is necessary to contain 0.0001% or more. On the other hand, if it exceeds 0.0050%, the toughness is deteriorated. Therefore, when contained, the B content is 0.0001% or more and 0.0050% or less, preferably 0.0010% or more and 0.0050% or less.
  • Mg 0.0001% or more and 0.0100% or less Mg is an element effective for fixing S in steel and improving the toughness of the weld heat affected zone. In order to obtain this effect sufficiently, it is necessary to contain 0.0001% or more. On the other hand, if it exceeds 0.0100%, the amount of inclusions in the steel increases, leading to deterioration of toughness. Therefore, when it contains, Mg content is 0.0001% or more and 0.0100% or less, Preferably, it is 0.0020% or more and 0.0050% or less.
  • R value (R1 value + R2 value) 0.5
  • R1 value [Cu] ⁇ 0.2 + [Ni] ⁇ 3 + [W] ⁇ 4 + [Nb] ⁇ 20 + [Sn] ⁇ 8.5
  • R2 value (Log 1.5 ([W] 2 +0.002) +16) ⁇ ((Log 2 ([Nb] ⁇ 0.1 + 0.001) +10) + (Log 2 ([Sn] ⁇ 0.1 + 0.
  • [M] shows content (mass%) of the element M, and is set to 0 when not containing.
  • the R value is an index indicating the weather resistance of the steel material, and the R value is set to 2.0 or more in order to obtain excellent weather resistance in a high salinity environment.
  • the structural steel material excellent in weather resistance according to the present invention is obtained by melting a steel having the above composition by a conventional method using a melting means such as a steel converter or an electric furnace, and performing normal continuous casting.
  • the heating and rolling conditions may be appropriately determined according to the required material, and a combination of heat treatment such as controlled rolling, accelerated cooling, or reheating is also possible.
  • the structural steel material obtained as described above as a structural member of a steel structure, it is possible to obtain a steel structure having excellent weather resistance in an environment with a large amount of incoming salt such as the vicinity of the coast.
  • a steel having a chemical composition shown in Table 1 is melted and heated to 1150 ° C., then hot rolled and air cooled to room temperature to produce a 6 mm thick steel plate. did.
  • a test piece of 35 mm ⁇ 35 mm ⁇ 5 mm was taken from the obtained steel plate.
  • the surface of the test piece is ground so that the surface roughness Ra is 1.6 ⁇ m or less, and the end face (edge face) and the back face (back side) are sealed with tape.
  • the surface was also sealed with tape so that the area of the exposed area was 25 mm ⁇ 25 mm.
  • the test piece obtained as described above was subjected to a dry and wet repeated corrosion test as a method for evaluating the weather resistance in a 0.4 mdd environment, and the thickness reduction amount was measured.
  • the dry and wet repeated corrosion test method and the thickness reduction measurement method are shown below. Dry and Wet Repeated Corrosion Test As shown in FIG. 1, a temperature and humidity cycle was performed on the above test piece in a state where salt was attached to one surface.
  • the temperature and humidity cycle consists of a drying process at a temperature of 40 ° C. and a relative humidity of 40% RH for 11 hours, a transition time of 1 hour, and then a temperature of 25 ° C. and a relative humidity of 95% RH for 11 hours.
  • Time was 1 hour, 24 hours was 1 cycle, and 12 weeks (84 cycles) were performed.
  • Adhesion of salt was performed a total of 12 times before the start of the temperature and humidity cycle and every 7 cycles of the temperature and humidity cycle (before the drying step of the temperature and humidity cycle).
  • the predetermined amount of the adjusted artificial seawater aqueous solution was apply
  • the thickness reduction amount is 11.8 to 13.9 ⁇ m, and it has excellent weather resistance. I understand.
  • the R value is less than 2.0, and the thickness reduction amount is 14.3 to 17.7 ⁇ m, which is large and inferior in weather resistance as compared with the present invention example.

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PCT/JP2012/055297 2011-02-25 2012-02-24 耐候性に優れた構造用鋼材 WO2012115280A1 (ja)

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CN201280010266.3A CN103392023B (zh) 2011-02-25 2012-02-24 耐候性优良的结构用钢材
KR1020157014711A KR20150067771A (ko) 2011-02-25 2012-02-24 내후성이 우수한 구조용 강재

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AU2014312968B2 (en) * 2013-08-29 2016-09-22 Nippon Steel Corporation Cu-Sn coexisting steel and method for manufacturing the same
CN111394558A (zh) * 2020-03-12 2020-07-10 唐山不锈钢有限责任公司 一种汽车空心稳定杆用钢带及其生产方法
CN113621867A (zh) * 2021-08-06 2021-11-09 联峰钢铁（张家港）有限公司 一种减少VD工序结合组分优化生产低成本20CrMoA圆钢的方法

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CN103451537B (zh) * 2013-08-16 2016-04-27 江苏省沙钢钢铁研究院有限公司 一种高焊接性能的低温耐候钢板及其生产方法
JP6128102B2 (ja) * 2014-11-22 2017-05-17 Ｊｆｅスチール株式会社 金属材料の遅れ破壊特性の評価方法及び金属材料
JP6601258B2 (ja) * 2016-02-22 2019-11-06 日本製鉄株式会社 バラストタンク用耐食鋼材
JP6658412B2 (ja) * 2016-09-06 2020-03-04 Ｊｆｅスチール株式会社 塗装耐久性に優れた構造用鋼材および構造物
JP6772942B2 (ja) * 2017-04-18 2020-10-21 日本製鉄株式会社 バラストタンク用耐食鋼材
JP7415140B2 (ja) * 2019-11-25 2024-01-17 日本製鉄株式会社 鋼材
JP7502594B2 (ja) * 2019-11-25 2024-06-19 日本製鉄株式会社 鋼材
JP7192824B2 (ja) * 2020-03-31 2022-12-20 Ｊｆｅスチール株式会社 耐火性および塗装耐食性に優れた構造用鋼材および構造物

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JP2004360063A (ja) * 2003-05-15 2004-12-24 Sumitomo Metal Ind Ltd 海浜耐候性に優れた鋼材およびそれを用いた構造物
JP2006118011A (ja) * 2004-10-22 2006-05-11 Sumitomo Metal Ind Ltd 海浜耐候性に優れた鋼材と構造物
JP2010163643A (ja) * 2009-01-14 2010-07-29 Jfe Steel Corp 耐候性に優れた構造用鋼材

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JP2004360063A (ja) * 2003-05-15 2004-12-24 Sumitomo Metal Ind Ltd 海浜耐候性に優れた鋼材およびそれを用いた構造物
JP2006118011A (ja) * 2004-10-22 2006-05-11 Sumitomo Metal Ind Ltd 海浜耐候性に優れた鋼材と構造物
JP2010163643A (ja) * 2009-01-14 2010-07-29 Jfe Steel Corp 耐候性に優れた構造用鋼材

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2014312968B2 (en) * 2013-08-29 2016-09-22 Nippon Steel Corporation Cu-Sn coexisting steel and method for manufacturing the same
CN111394558A (zh) * 2020-03-12 2020-07-10 唐山不锈钢有限责任公司 一种汽车空心稳定杆用钢带及其生产方法
CN111394558B (zh) * 2020-03-12 2021-12-03 唐山不锈钢有限责任公司 一种汽车空心稳定杆用钢带及其生产方法
CN113621867A (zh) * 2021-08-06 2021-11-09 联峰钢铁（张家港）有限公司 一种减少VD工序结合组分优化生产低成本20CrMoA圆钢的方法
CN113621867B (zh) * 2021-08-06 2022-03-18 联峰钢铁（张家港）有限公司 一种减少VD工序结合组分优化生产低成本20CrMoA圆钢的方法

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KR20150067771A (ko) 2015-06-18
JP5120472B2 (ja) 2013-01-16
MY153633A (en) 2015-03-03
CN103392023A (zh) 2013-11-13
KR20130123431A (ko) 2013-11-12
CN103392023B (zh) 2015-09-30

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