EP1094126A1 - Produit en acier resistant a la corrosion atmospherique - Google Patents

Produit en acier resistant a la corrosion atmospherique Download PDF

Info

Publication number
EP1094126A1
EP1094126A1 EP00915415A EP00915415A EP1094126A1 EP 1094126 A1 EP1094126 A1 EP 1094126A1 EP 00915415 A EP00915415 A EP 00915415A EP 00915415 A EP00915415 A EP 00915415A EP 1094126 A1 EP1094126 A1 EP 1094126A1
Authority
EP
European Patent Office
Prior art keywords
less
steel
weathering
steel material
content
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP00915415A
Other languages
German (de)
English (en)
Other versions
EP1094126A4 (fr
Inventor
Tatsumi Tech. Res. Lab. Kawasaki Ste. Corp KIMURA
Kazuhiko Technical Research Laboratories SHIOTANI
Fumimaru Technical Research Laboratories Kawabata
Keniti Technical Research Laboratories Amano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
Kawasaki Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Publication of EP1094126A1 publication Critical patent/EP1094126A1/fr
Publication of EP1094126A4 publication Critical patent/EP1094126A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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
    • C22C38/002—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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • C22C38/16—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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • 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
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of 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
    • C22C38/18—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
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
    • 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
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron

Definitions

  • This invention concerns weathering resistant steel materials and, it relates to a flow rust reducing weathering resistant steel materials capable of effectively reducing occurrence of flow rust in relatively less salty circumstances such as mountain districts, rural districts and industrial districts, as well as steel materials excellent in earthquake proofness and coast weathering resistance applicable as steel structures such as bridges used in salty circumstances such as coast districts.
  • the weathering resistance referred to in the invention means weathering resistance in a case of use in atmospheric air of coast districts.
  • Weathering resistant steels with improved weathering resistance in atmospheric air with addition of alloying elements such as P, Cu, Cr and Ni in the steels have been used generally for structures such as bridges.
  • the weathering resistant steels form, in several years, rust referred to as stable rust less permeating oxygen and water causing corrosion and suppress subsequent corrosion. Accordingly, the weathering resistant steels require no coating of anti-rust paints and they are highly corrosion resistant material which can be used in a so-called naked state.
  • Japanese Patent Laid-Open No. 136557/1994 proposes a surface treating method for steel materials of coating an aqueous solution of chromium sulfate or an aqueous solution of copper sulfate and further applying organic resin coating after drying the water content.
  • Japanese Patent Laid-Open No. 13158/1996 proposes a surface treating method of steel materials of coating an aqueous solution containing aluminum ions and further forming an organic resin film after drying of the water content.
  • the invention intends to provide flow rust reducing weathering resistant steel materials capable of reducing occurrence of flow rust in the course of forming stable rust in weathering resistant steels used in a naked state.
  • the weathering resistant steels are those steel materials with addition of P, Cu, Ni and Cr in which stable rusts as protective films are formed in several years on the surface of steels in an atmospheric circumstance. Since the stable rust suppresses further development of corrosion, corrosion of the steel materials can be minimized. Accordingly, most of them are used with no coating.
  • Japanese Patent No. 2572447, Japanese Patent Laid-Open NO. 51668/1993 and Japanese Patent Laid-Open No. 134587/1996 propose methods of improving the coast weathering resistance by adding a great amount of alloying elements such as P, Cu, Ni and Mo to steel materials.
  • the corrosive circumstance for steel materials are not always identical depending on the places to be used.
  • four main beam bridge while outside of the beams are exposed to rainfall, water of condensation and sunshine, inside of the beam are exposed only to water of condensation but not suffer from rainfall.
  • the extent of corrosion is less in the inside of the beams when compared between the inside and the outside of the beams.
  • the extent of corrosion is rather greater in the inside of the beam than the outside of the beam. This reversal phenomenon occurs at a certain content of the atmospheric salt content as a boundary but the content can not be specified.
  • the structural steel materials of this type utilized, for example, in bridge beams have been demanded to have an absorption energy of 47J or more at -5°C in a Chalpy impact test in the rolling direction (L direction) and a cross direction (C direction) to the rolling direction of the steel materials in view of the safety.
  • the invention intends to provide a steel material capable of forming stable rust with good protective performance in relatively less salty districts and salty circumstance such as coast districts, regardless of rainfalls, excellent in weather proofness and excellent in earthquake proofness with improved toughness in the direction of Z also including the weld heat affective zone.
  • the present inventors have made an earnest study for the thickness capable of reducing flow rust in weathering resistant steels and, as a result, have found that a weathering resistant steel material capable of outstandingly reducing the amount of flow rust by adding B and, further, by controlling the content of B and the content of one or more of P, Cu, Ni, Cr and Mo based on a certain relationship to each other.
  • a flow rust reducing weathering resistant steel material having a composition containing, on the weight % basis, C: from 0.001% to 0.050%, Si: 0.60% or less, Mn: from 0.50% to 3.00%, S: 0.01% or less, Al: 0.10% or less and B: from 0.0003% to 0.0050% and, further, one or more of elements selected from P: from 0.005% to 0.15%, Cu; from 0.1% to 2.0%, Ni: from 0.1% to 6.0%, Cr: from 0.005% to 1.0% and Mo: from 0.005% to 1.0%, and satisfying the following equation (1): (20P + 3Cu + 3Ni + 6Cr + Mo)/(1-0.2(10000B) 0.4 ) ⁇ 18 in which P, Cu, Ni, Cr, Mo, B: content for each element (wt%)), and the balance of Fe and inevitable impurities.
  • one or more of elements selected from Nb: from 0.005% to 0.20%, Ti: from 0.005% to 0.20%, V: from 0.005% to 0.20%, on the weight % basis, may be contained in addition to the composition described above.
  • one or more of elements selected from Ca: 0.02% or less and REM: 0.02% or less may be contained, on the weight % basis, in addition to the composition described above.
  • the present inventors have made an earnest study for improving the coast weathering resistance and, as a result, have obtained a knowledge that Cr degrade the weathering resistance in circumstance containing much salt. Further, the present inventors have found that steel materials of excellent weathering resistance even in salty circumstances such as coast districts can be obtained by controlling the content of B and the content of one or more of P, Cu, Ni and Mo in relation the atmospheric salt content.
  • the inventors have found that the sum of inclusions, particularly, the amount of A series and B series inclusions gives a significant effect on the toughness in the Z direction and the toughness in the Z direction can be improved remarkably by restricting the sum (dA + dB) value for the A series inclusion amount and the B series inclusion amount according to JIS G 0555 to 0.030% or less.
  • Steels were prepared by melting while variously changing the forms and the amount of inclusions into steel plates of 60 mm thickness by hot rolling.
  • Test pieces for microscopic observation and test pieces for Chalpy impact shock in the Z direction were sampled from the steel plates, and the form and the amount of inclusions and the toughness in the Z direction (adsorption energy) were measured.
  • Fig. 1 shows a relation between the sum (dA + dB) value of the A type inclusions and the amount of B type inclusions according to JIS G 0555 and the Chalpy absorption energy ( V E -5 ) in the Z direction at -5°C.
  • V E -5 the Chalpy absorption energy
  • Fig. 2 shows a relation between the dC value for the amount of C type inclusions according to JIS G 0555 and the Chalpy absorption energy in the Z direction at -5°C ( V E -5 ).
  • the relation between the dC value and V E -5 is shown for the steel plates having the (dA + dB) value within range from 0.021% to 0.028%, which show high toughness in the Z direction.
  • the inventors have obtained the knowledge that control of the sum (dA + dB) value for the A type inclusions and the B type inclusions is important for improving the toughness in the direction of the plate thickness. Particularly, it has been found that the toughness in the direction of the plate thickness is improved remarkably by defining the (dA + dB) value to 0.030% or less.
  • Fig. 1 and Fig. 2 show the knowledge obtained from the coast weathering resistant steel materials and similar results have also been obtained for the flow rust reducing weathering resistant steel materials (Fig. 3 and Fig. 4).
  • C is an element for increasing the strength and a content of 0.001% or more is necessary in order to obtain a desired strength but the toughness is degraded when it is contained by a great amount of exceeding 0.050%, so that it is defined as from 0.001% to 0.050% in the invention.
  • it is from 0.005% to 0.030%. Further preferably, it is from 0.005% to 0.025%.
  • Si is an element acting as a deoxidizer and increasing the strength of the steel but, since the toughness and the weldability are degraded if it is contained by a greater amount, it is defined to 0.60% or less. Preferably, it is from 0.15% to 0.50%.
  • Mn is an element greatly contributing to the increase of the strength and the toughness of the steel and it is necessary to be contained by 0.50% or more in order to ensure the desired strength in the invention. However, when it is contained by a greater amount exceeding 3.00%, it gives an undesired effect on the toughness and the weldability, so that it is defined within a range from 0.50% to 3.00%. Preferably, it is 0.50% to 1.80%.
  • S degrades the weathering resistance and further degrades the weldability and the toughness, it is defined to 0.01% or less.
  • the toughness in the direction of the plate thickness and degrades the weathering resistance it is defined as 0.005% or less and, it is preferably 0.003% or less with a view point of the toughness.
  • Al acts as a deoxidizer but since it gives an undesired effect on the weldability when contained in excess of 0.10%, the upper limit is defined to 0.10%.
  • Al is added as a deoxidizer but, when it is contained in excess of 0.10%, the B type inclusions increase to lower the toughness in the direction of the plate thickness due to the formation of alumina clusters. Accordingly, Al is defined to 0.10% or less and it is preferably, 0.05% or less with a view point of the toughness.
  • B is an element for improving the hardenability and also improving the weathering resistance and is an important element in the invention. Such an effect is recognized by the content of 0.0003% or more but no corresponding effect to the content can be expected even if it is contained in excess of 0.0050%. Accordingly, B is defined within a range from 0.0003% to 0.0050%. Preferably, it is within a range from 0.0003% to 0.0030%.
  • P is an element for promoting the anodic dissolution of the matrix in the early stage of corrosion and making the rust grains more dense and it is preferably incorporated positively in this invention. Such an effect is not recognized when the P content is less than 0.005%. However, when it exceeds 0.15%, the effect of improving the weathering resistance is saturated and, further, the weldability is degraded. Accordingly, it is preferred to define P within a range from 0.005% to 0.15%. Preferably it is from 0.010% to 0.120%.
  • Cu has an effect like P. That is, this is an element for promoting the anodic dissolution of the matrix in the early stage of corrosion and making the rust grains more dense.
  • the effect is insignificant if the Cu content is less than 0.1% and, on the other hand, if it exceeds 2.0%, it hinders hot workability, the effect of improving the weathering resistance is saturated to result in economical disadvantage. Therefore, the content of Cu is preferably within a range from 0.1% to 2.0%. It is preferably within a range from 0.1% to 1.5%.
  • Ni densifies the rust grains to improve the weathering resistance but the effect is insignificant if it is less than 0.1%. On the other hand, even if it is incorporated in excess of 6.0%, the effect is saturated and the effect corresponding to the content can not be recognized to result in economical disadvantage. Therefore, Ni is preferably within a range from 0.1% to 6.0%. With a view point of the weathering resistance, a range from 0.1% to 3.5% is desirable.
  • Cr is an element for improving the weathering resistance as far as less salty circumstance is concerned.
  • the effect is insufficient at the content of less than 0.005%.
  • the Cr content is suitably within a range from 0.005% to 1.0%.
  • Mo improves the weathering resistance and, further, increases the strength but the effect is insufficient at the content less than 0.005%. On the other hand, even when it is contained in excess of 1.0%, the effect is saturated and no corresponding effect to the content is recognized, to result in economical disadvantage. Accordingly, Mo is preferably within a range from 0.005% to 1.0%. With a view point of the toughness, it is preferably within a range from 0.005% to 0.5%.
  • the foregoing effects can be provided by selecting one or more of five elements of P, Cu, Ni, Cr and Mo and incorporating them respectively within the ranges described above.
  • the content for each of the five elements has to be controlled in relation with B so as to satisfy the following equation (1): (20P + 3Cu + 3Ni + 6Cr + Mo)/(1-0.2(10000B) 0.4 ) ⁇ 18 (where P, Cu, Ni, Cr, Mo, B: content for each element (wt%)). This can outstandingly reduce the amount of flow rust formed.
  • Fig. 5 is a graph for the result obtained by an atmospheric exposure test for weathering resistant steel plates having various compositions for one year in rural districts, taking the value in the leftside of the equation (1) (referred to as A value) on the abscissa and the amount of flow rust (Fe 2+ ) from the test specimens on the ordinate. As can be seen from the graph, the amount of flow rust is drastically reduced by defining the A value to 18 or more.
  • the P content and the content of one or more of P, Cu, Ni and Mo are controlled, in relation with the atmospheric salt content, so as to satisfy the following equation (1); (11P + 4.0Cu 4 3.1Ni + 2.6Mo)/(1-0.1(10000B) 0.35 ) ⁇ 1 + 13X (where P, Cu, Ni, Cr, Mo, B: content for each element (wt%), X: atmospheric salt content (mg/dm 2 /day)).
  • the weathering resistance in coast districts with high atmospheric salt content is improved remarkably by controlling the content for B and the content for one or more of P, Cu, Ni and Mo so as to satisfy the equation (1). Further, steel materials coping with corrosive circumstance (atmospheric salt content X) are obtained by controlling the content for B. P, Cu, Ni and Mo in accordance with the atmospheric salt content X, which can prevent incorporation of unnecessary alloying elements to provide economical advantage.
  • Nb from 0.005% to 0.20%
  • Ti from 0.005% to 0.20%
  • V from 0.005% to 0.20%.
  • Nb, V and Ti are elements increasing the strength of steel and one or more of them can be added as required.
  • the effect is recognized by the incorporation of 0.005% or more but the effect is saturated even when it is contained in excess of 0.20% respectively. Accordingly, it is desirable that each of Nb, V and Ti is from 0.005% to 0.20%.
  • REM and Ca have an effect of improving the weldability and can be added as required.
  • the effect is recognized by the addition of 0.0005% or more for any of REM and Ca but the upper limit is defined as 0.02% since addition of a greater amount degrades the cleanliness of the steel material.
  • the steel material according to this invention comprises the balance Fe and inevitable impurities.
  • the inevitable impurities L: 0.010% or less and O: 0.010% or less are allowable.
  • Cr 0.1% or less
  • N 0.010% or less
  • O 0.010% or less
  • Cr is added to weathering resistant steels marketed at present as an element for improving the corrosion resistance.
  • the element rather deteriorates the weathering resistance and, accordingly, this is not positively added in this invention but it is allowable up to 0.1% as inevitable impurities.
  • the sum (dA + dB) value for the amount of A type inclusions and the amount of B type inclusion according to JIS G 0555 is defined as 0.030% or less considering the earthquake proofness and with a view point of ensuring the toughness in the Z direction (absorption energy in a Chalpy impact test) of 47J or more at -5°C.
  • the A type impurities are plastically deformed by processing and B type impurities comprise granular inclusions arranged discontinuously grouped in the processing direction.
  • B type impurities comprise granular inclusions arranged discontinuously grouped in the processing direction.
  • C type impurities inclusions dispersing irregularly with no plastic deformation
  • the toughness in the Z direction is improved remarkably by defining the (dA + dB) value to 0.030% or less. It is considered that the A type or B type inclusions have sensitive effect on the toughness in the Z direction as stress concentration sources. It is considered that decrease in the amount of the A type or B type inclusions (dA + dB) decreases the stress concentration sources, and, particularly, reduces the (dA + dB) value to 0.030% to thereby decrease the size of the inclusions, so that the toughness in the Z direction is improved remarkably. Further, the corrosion resistance is also improved by reducing the (dA + dB) value. This is considered that local corrosion resulting from the matrix and the inclusion boundary is suppressed by the decrease in the amount of the impurities.
  • the steel melting according to the invention is prepared by welding with a ordinary known melting method such as a converter method or an electric furnace method and prepared into steel materials by continuous casting method or casting method. Further, in the melting step, a vacuum degasing refining may be practiced. Then, the steel materials are after being heated in a heating furnace or the like and rolled to a desired shape by hot rolling or directly not by way of heating. Further, the steel materials according to this invention includes, for example, steel plates, steel sheets, bar steels and profiled steels.
  • Examples of the invention are excellent both in the toughness and the weldability.
  • comparative examples (steel type: Nos. 12 - 21) and an existent example (steel type: No. 22) have comparable characteristics with those in the examples of this invention excepting that they were degraded in those in which the content for S, Cu and P are out of the upper limit for the range of the invention (steel type: Nos. 13, 17, 18).
  • the amount of flow rust in the examples of this invention is as less as 29 ⁇ g/cm 3 to 67 ⁇ g/cm 3 , which is remarkably lowered compared with 420 ⁇ g/cm 2 of the existent example (steel type No. 22) with no addition of B and with lower A value, and the reduction of the plate thickness is 8 ⁇ m to 23 ⁇ m in the example of the invention, which is smaller compared with 38 ⁇ m in the existent example, so that it can be seen that the steel material according to the invention has excellent weathering resistance.
  • the amount of flow rust in the comparative examples (steel type: Nos. 12 - 16, 20, 21) out of the range of the invention is increased as 300 ⁇ g/cm 2 to 390 ⁇ g/cm 2 compared with the examples of this invention.
  • the amount of the flow rust is large in each of cases, that is, in No. 12 since the P content and the A value are excessively low, in No. 13 since the S content is excessively high and the A value is excessively low, in No. 14 since the Cu content and the A value are excessively low, in No. 15 since the B content and the A value are excessively low and in Nos. 20, 21 since the A value is excessively low.
  • the comparative example with excessively high P content (steel type: No. 17) and the comparative example with excessively high Cu content (steel type: No. 18) are comparable with the examples of the invention in view of the weathering resistance (amount of flow rust, reduction of plate thickness) but the toughness and the weldability are degraded.
  • the comparative example of excessively high Ni content (steel type No. 19) is comparable with the examples of this intention in view of the weathering resistance, the toughness and the weldability but the elongation is poor since the strength is excessively high.
  • test specimens were sampled at the positions in the L direction and the Z direction at the central portion of the plate thickness (1/2t part) for the steel plates, and in the L direction and the Z direction at the central part of the plate thickness of a flange 1/4 part (1/2t part) for the H steels.
  • the Chalpy impact test pieces for the direction of the plate thickness (Z direction) were sampled such that steel plates were pressure welded to the surface and the rear face of steel plates to increase the plate thickness up to 55 mm and the notch part was at 1/2t part. The pressure welding was applied under the condition considering so as not to change the tissue and the nature for the 1/2t part.
  • corrosion test pieces each of 5 mm x 50 mm x 100 mm were sampled from the steel plates and H steels, shot blasted and served to an atmosphere exposure test to evaluate the weathering resistance.
  • atmosphere exposure test a rural district at an atmospheric salt content of 0.01 mg/dm 2 /day was selected and each of the test specimens was placed being directed to a south direction and at an angle of 30° relative to the ground surface and exposed for one year. Simultaneously, the amount of the flow rust (Fe 2+ ) from the specimens was measured. After the exposure test, a rust layer formed on the surface of the matrix was removed and the weight reduction of the test specimens was measured, which was converted into the reduction of weight thickness.
  • Examples of the invention (steel materials Nos. 1 to 17) have high toughness of V E -5 : 61J or more including also the toughness in the Z direction. Further, the examples of this invention are excellent in the weathering resistance evaluated based on the reduction of the plate thickness and the amount of flow rust.
  • the amount of the flow rust in the examples of this invention (steel material No. 1 to steel material No. 17) is as small as 25 ⁇ g/cm 2 to 68 ⁇ g/cm 2 , which was remarkably decreased compared with 420 ⁇ g/cm 2 for the amount of the flow rust in the existent example (steel material No. 26), and it can be seen that the steel materials according to this invention have excellent weathering resistance.
  • test specimens were sampled at a position for a central part of the plate thickness (1/2t part) (L direction) in the steel plates and for a flange 1/4B part (1/2t part) (L direction) in the H steels.
  • Chalpy impact test in the direction of the plate thickness (Z direction) was also applied.
  • the Chalpy impact test pieces for the direction of the plate thickness (Z direction) were sampled such that steel plates were pressure welded to the surface and the rear face of steel plates to increase the plate thickness up to 55 mm and the notch part was at 1/2t part.
  • the pressure welding was applied under the condition considering so as not to change the tissue and the nature for the 1/2t part.
  • Corrosion test pieces each of 5 mm x 50 mm x 100 mm were sampled from the steel plates and the H steels, shot blasted and then served to an atmospheric exposure test to evaluate the weathering resistance.
  • the reduction of plate thickness in the examples of the invention is from 6 ⁇ m to 32 ⁇ m, which is remarkably smaller than the reduction of plate thickness (143 ⁇ m) of comparative example (marketed weathering resistant steel, steel material No. 19) showing excellent coast weathering resistance.
  • the toughness in the Z direction in the examples of this invention shows excellent earthquake proofness as V E -5 of 59J or more.
  • any of the examples of the invention shows excellent earthquake proofless including the weld portion having V E -5 at the weld heat affect zone of 169 J or more. Further, the yield ratio was as low as 76% in the examples of this invention, which are excellent in the earthquake proofness.
  • the reduction of the plate thickness of the steel No. 16 with high P content is comparable with the examples of this invention and the coast weathering resistance is excellent, but the toughness in the Z direction is as low as V E -5 : 33J to lower the earthquake proofness and, further the toughness in the HAZ zone is as low as V E -5 : 31J to lower the weldability.
  • test specimens were sampled at a position for a central part of the plate thickness (1/2t part) (C direction) in the steel plates and for a flange 1/4B part (1/2t part) (L direction) in the H steels.
  • Chalpy impact test in the direction of the plate thickness (Z direction) was also applied.
  • the Chalpy impact test pieces for the direction of the plate thickness (Z direction) were sampled such that steel plates were pressure welded to the surface and the rear face of steel plates to increase the plate thickness up to 55 mm and the notch part was at 1/2t part.
  • the pressure welding was applied under the condition considering so as not to change the tissue and the nature for the 1/2t part.
  • corrosion test pieces each of 5 mm x 50 mm x 100 mm were sampled from the steel plates and the H steels, shot blasted and then served to an atmospheric exposure test to evaluate the weathering resistance.
  • the reduction of plate thickness in the examples of this invention is from 14 ⁇ m to 40 ⁇ m, which is remarkably smaller than the reduction of plate thickness (105 ⁇ m) of comparative example (marketed weathering resistant steel, steel material Nos. 2 to 16) showing excellent coast weathering resistance.
  • the toughness in the Z direction in the examples of the invention shows excellent earthquake proofness as V E -5 of 70J or more.
  • any of the examples of this invention shows excellent earthquake proofless including the weld portion having V E -5 at the weld heat affect zone of 292 J or more. Further, the yield ratio was as low as 80% in the examples of this invention, which are excellent in the earthquake proofness.
  • the reduction of plate thickness shows substantially the same value as that of the invented steels but since the amount of inclusions is more and the (dA + dB) value is higher than 0.030%, the toughness in the Z directions is lowered to result in a problem in view of the earthquake proofness.
  • the steel material according to this invention is a steel material excellent in weathering resistance for coast districts with high atmospheric salt content (coast weathering resistance) and further excellent in the toughness in the Z direction also including the weld portion and excellent in earthquake proofness, which can be seen suitable as the steel materials for use in steel structures.
  • weathering resistant steel materials excellent in the earthquake proofness and reduced flow rust can be provided.
  • the coating, surface treatment or the like can be saved to give an expectation for the economical effect of reducing the maintenance cost to provide an outstandingly excellent industrial effect.
  • steel materials capable of forming stable rust with good protective performance, excellent in the coast weathering resistance and excellent earthquake proofness also including the weld heat affect zone can be manufactured at inexpensively.
  • the steel materials according to the invention can save the painting or surface treatment even in salty circumstances such as coast districts, which can also expect an economical effect of saving the maintenance cost and also can provide a remarkable industrial effect.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
EP00915415A 1999-04-08 2000-04-07 Produit en acier resistant a la corrosion atmospherique Withdrawn EP1094126A4 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP10174399 1999-04-08
JP10174399 1999-04-08
JP10763999 1999-04-15
JP10763999 1999-04-15
PCT/JP2000/002274 WO2000061829A1 (fr) 1999-04-08 2000-04-07 Produit en acier resistant a la corrosion atmospherique

Publications (2)

Publication Number Publication Date
EP1094126A1 true EP1094126A1 (fr) 2001-04-25
EP1094126A4 EP1094126A4 (fr) 2003-03-05

Family

ID=26442562

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00915415A Withdrawn EP1094126A4 (fr) 1999-04-08 2000-04-07 Produit en acier resistant a la corrosion atmospherique

Country Status (5)

Country Link
EP (1) EP1094126A4 (fr)
KR (1) KR20010043879A (fr)
AU (1) AU768461B2 (fr)
CA (1) CA2333526A1 (fr)
WO (1) WO2000061829A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1026277A1 (fr) * 1998-06-17 2000-08-09 Kawasaki Steel Corporation Materiau en acier resistant aux intemperies
US7686898B2 (en) 2004-10-29 2010-03-30 Alstom Technology Ltd Creep-resistant maraging heat-treatment steel
EP2218800A1 (fr) * 2007-12-07 2010-08-18 Nippon Steel Corporation Acier avec zone affectée par la chaleur de soudage possédant d'excellentes propriétés ctod et procédé de fabrication de l'acier
US7922968B2 (en) * 2005-10-25 2011-04-12 Posco Corrosion resistance improved steel sheet for automotive muffler and method of producing the steel sheet
US8668784B2 (en) 2009-05-19 2014-03-11 Nippon Steel & Sumitomo Metal Corporation Steel for welded structure and producing method thereof
CN103667969A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN103667968A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN106521360A (zh) * 2016-10-26 2017-03-22 南京钢铁股份有限公司 一种免涂装耐候圆钢的生产方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1825014B1 (fr) * 2004-11-12 2012-04-11 Posco Procede de fabrication d'un acier a excellente resistance aux intemperies dans une atmosphere marine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6052522A (ja) * 1983-08-31 1985-03-25 Nippon Steel Corp 耐候性鋼材の製造方法
EP0528407A1 (fr) * 1991-08-19 1993-02-24 Kawasaki Steel Corporation Tôles d'acier laminées à froid ayant une tenacité élevée et une bonne aptitude à l'emboutissage profond
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
JPH08225888A (ja) * 1995-02-14 1996-09-03 Nkk Corp 化成処理性に優れた耐食性鋼板およびその冷延鋼板の製造方法
JPH09137218A (ja) * 1995-11-13 1997-05-27 Kawasaki Steel Corp 建築構造用ｈ形鋼の製造方法
JPH09316617A (ja) * 1996-05-31 1997-12-09 Kawasaki Steel Corp 高加工性めっき鋼板の製造方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS52150324A (en) * 1976-06-10 1977-12-14 Nippon Steel Corp Steel of extremely low sulfure content and its production method
JPS62256947A (ja) * 1986-04-28 1987-11-09 Kobe Steel Ltd 溶接性及び低温靭性に優れた調質高燐型耐候性鋼板
JPH059570A (ja) * 1991-07-03 1993-01-19 Nippon Steel Corp 高溶接性高強度鋼の製造法
JPH08143954A (ja) * 1994-11-17 1996-06-04 Kobe Steel Ltd 耐溶接割れ性の優れた引張強さ７８０Ｎ／ｍｍ２級鋼板の製造方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6052522A (ja) * 1983-08-31 1985-03-25 Nippon Steel Corp 耐候性鋼材の製造方法
EP0528407A1 (fr) * 1991-08-19 1993-02-24 Kawasaki Steel Corporation Tôles d'acier laminées à froid ayant une tenacité élevée et une bonne aptitude à l'emboutissage profond
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
JPH08225888A (ja) * 1995-02-14 1996-09-03 Nkk Corp 化成処理性に優れた耐食性鋼板およびその冷延鋼板の製造方法
JPH09137218A (ja) * 1995-11-13 1997-05-27 Kawasaki Steel Corp 建築構造用ｈ形鋼の製造方法
JPH09316617A (ja) * 1996-05-31 1997-12-09 Kawasaki Steel Corp 高加工性めっき鋼板の製造方法

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 009, no. 184 (C-294), 30 July 1985 (1985-07-30) & JP 60 052522 A (SHIN NIPPON SEITETSU KK), 25 March 1985 (1985-03-25) *
PATENT ABSTRACTS OF JAPAN vol. 017, no. 582 (C-1123), 22 October 1993 (1993-10-22) & JP 05 171265 A (SUMITOMO METAL IND LTD), 9 July 1993 (1993-07-09) *
PATENT ABSTRACTS OF JAPAN vol. 1997, no. 01, 31 January 1997 (1997-01-31) & JP 08 225888 A (NKK CORP), 3 September 1996 (1996-09-03) *
PATENT ABSTRACTS OF JAPAN vol. 1997, no. 09, 30 September 1997 (1997-09-30) & JP 09 137218 A (KAWASAKI STEEL CORP), 27 May 1997 (1997-05-27) *
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 04, 31 March 1998 (1998-03-31) & JP 09 316617 A (KAWASAKI STEEL CORP), 9 December 1997 (1997-12-09) *
See also references of WO0061829A1 *

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1026277A4 (fr) * 1998-06-17 2002-08-21 Kawasaki Steel Co Materiau en acier resistant aux intemperies
EP1026277A1 (fr) * 1998-06-17 2000-08-09 Kawasaki Steel Corporation Materiau en acier resistant aux intemperies
US7686898B2 (en) 2004-10-29 2010-03-30 Alstom Technology Ltd Creep-resistant maraging heat-treatment steel
US7922968B2 (en) * 2005-10-25 2011-04-12 Posco Corrosion resistance improved steel sheet for automotive muffler and method of producing the steel sheet
US8361248B2 (en) 2007-12-07 2013-01-29 Nippon Steel Corporation Steel superior in CTOD properties of weld heat-affected zone and method of production of same
EP2218800A4 (fr) * 2007-12-07 2011-07-27 Nippon Steel Corp Acier avec zone affectée par la chaleur de soudage possédant d'excellentes propriétés ctod et procédé de fabrication de l'acier
EP2218800A1 (fr) * 2007-12-07 2010-08-18 Nippon Steel Corporation Acier avec zone affectée par la chaleur de soudage possédant d'excellentes propriétés ctod et procédé de fabrication de l'acier
US8668784B2 (en) 2009-05-19 2014-03-11 Nippon Steel & Sumitomo Metal Corporation Steel for welded structure and producing method thereof
CN103667969A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN103667968A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN103667969B (zh) * 2012-08-31 2016-01-27 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN103667968B (zh) * 2012-08-31 2016-01-27 宝山钢铁股份有限公司 一种利用低温在线静态再结晶生产钢带的方法
CN106521360A (zh) * 2016-10-26 2017-03-22 南京钢铁股份有限公司 一种免涂装耐候圆钢的生产方法

Also Published As

Publication number Publication date
KR20010043879A (ko) 2001-05-25
CA2333526A1 (fr) 2000-10-19
EP1094126A4 (fr) 2003-03-05
AU768461B2 (en) 2003-12-11
AU3673600A (en) 2000-11-14
WO2000061829A1 (fr) 2000-10-19

Similar Documents

Publication Publication Date Title
KR101241935B1 (ko) 선박용 열간 압연 형강 및 그의 제조 방법
EP2231892B1 (fr) Acier résistant à la corrosion pour applications marines
JP2002180187A (ja) 日陰耐候性に優れた高強度・高靱性耐候性鋼
CN107034418A (zh) 一种混凝土用400MPa级耐氯离子腐蚀高强钢筋及其生产方法
EP1094126A1 (fr) Produit en acier resistant a la corrosion atmospherique
KR20130006546A (ko) 원유 탱크용 열간 압연 형강 및 그의 제조 방법
KR20110105400A (ko) 용접 변형이 작고 내식성이 뛰어난 강판
US6699338B2 (en) Method of manufacturing corrosion resistant steel materials
JP3367608B2 (ja) 耐候性鋼材
US20020011286A1 (en) Steel plate for paint use and manufacturing method thereof
JP4317517B2 (ja) 加工性・溶接熱影響部靭性に優れた高耐食性熱延鋼板およびその製造法
JP2002053929A (ja) 高耐候性鋼材
JP7405246B2 (ja) Ｈ形鋼
JP7327444B2 (ja) 厚鋼板、厚鋼板の製造方法、および構造物
KR101442366B1 (ko) 용접 변형이 작고 내식성이 우수한 강판
JP3506028B2 (ja) 流れさび低減耐候性鋼材
JP4505966B2 (ja) 耐土壌腐食性および耐震性に優れた圧延形鋼およびその製造方法
JP2000355730A (ja) 溶接熱影響部靱性に優れた海岸耐候性鋼材
JP4218139B2 (ja) テーパ鋼材の製造方法
JP2024014856A (ja) 鋼板およびその製造方法
JP2000355731A (ja) 耐震性に優れた高海岸耐候性鋼材
JP2023132089A (ja) 鋼材
JP2023014997A (ja) 鋼板およびその製造方法
JP2000355732A (ja) 耐震性に優れた流れさび低減耐候性鋼材
JP2000212697A (ja) 海岸用耐候性鋼材

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20001204

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RIC1 Information provided on ipc code assigned before grant

Free format text: 7C 22C 38/58 A, 7C 22C 38/04 B, 7C 22C 38/16 B, 7C 22C 38/54 B

RIC1 Information provided on ipc code assigned before grant

Ipc: 7C 22C 38/04 A

Ipc: 7C 22C 38/16 B

Ipc: 7C 22C 38/00 B

A4 Supplementary search report drawn up and despatched

Effective date: 20030117

17Q First examination report despatched

Effective date: 20030709

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: JFE STEEL CORPORATION

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20040120