EP2196552A1 - Rail en acier perlitique à dureté interne élevée dont la résistance à l'usure, à la rupture par fatigue et à la fracture retardée sont excellentes ainsi que son procédé de fabrication - Google Patents
Rail en acier perlitique à dureté interne élevée dont la résistance à l'usure, à la rupture par fatigue et à la fracture retardée sont excellentes ainsi que son procédé de fabrication Download PDFInfo
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- EP2196552A1 EP2196552A1 EP08739390A EP08739390A EP2196552A1 EP 2196552 A1 EP2196552 A1 EP 2196552A1 EP 08739390 A EP08739390 A EP 08739390A EP 08739390 A EP08739390 A EP 08739390A EP 2196552 A1 EP2196552 A1 EP 2196552A1
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 8
- 229910000831 Steel Inorganic materials 0.000 title claims description 27
- 239000010959 steel Substances 0.000 title claims description 27
- 229910001562 pearlite Inorganic materials 0.000 title claims description 25
- 238000000034 method Methods 0.000 title claims description 13
- 230000003111 delayed effect Effects 0.000 title abstract description 41
- 238000005096 rolling process Methods 0.000 claims abstract description 78
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 52
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 51
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 39
- 239000002344 surface layer Substances 0.000 claims abstract description 28
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 27
- 239000000203 mixture Substances 0.000 claims abstract description 19
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 238000001816 cooling Methods 0.000 claims description 34
- 229910052710 silicon Inorganic materials 0.000 claims description 30
- 238000010791 quenching Methods 0.000 claims description 18
- 230000009466 transformation Effects 0.000 claims description 15
- 229910052799 carbon Inorganic materials 0.000 claims description 14
- 239000010410 layer Substances 0.000 claims description 8
- 229910052698 phosphorus Inorganic materials 0.000 claims description 8
- 229910052717 sulfur Inorganic materials 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 6
- 238000005098 hot rolling Methods 0.000 claims description 4
- 238000012360 testing method Methods 0.000 description 42
- 230000015572 biosynthetic process Effects 0.000 description 18
- 229910000734 martensite Inorganic materials 0.000 description 17
- 230000000694 effects Effects 0.000 description 13
- 229910001566 austenite Inorganic materials 0.000 description 6
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 6
- 229910001567 cementite Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 150000004767 nitrides Chemical class 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 239000012925 reference material Substances 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- SOIFLUNRINLCBN-UHFFFAOYSA-N ammonium thiocyanate Chemical compound [NH4+].[S-]C#N SOIFLUNRINLCBN-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910019582 Cr V Inorganic materials 0.000 description 2
- 241000446313 Lamella Species 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 239000004365 Protease Substances 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 239000004205 dimethyl polysiloxane Substances 0.000 description 1
- 229910001651 emery Inorganic materials 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- FFNMBRCFFADNAO-UHFFFAOYSA-N pirenzepine hydrochloride Chemical compound [H+].[H+].[Cl-].[Cl-].C1CN(C)CCN1CC(=O)N1C2=NC=CC=C2NC(=O)C2=CC=CC=C21 FFNMBRCFFADNAO-UHFFFAOYSA-N 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 238000004781 supercooling Methods 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/002—Heat treatment of ferrous alloys containing Cr
-
- 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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- 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
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
-
- 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
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/04—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rails
-
- 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
- C22C38/04—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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/08—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling structural sections, i.e. work of special cross-section, e.g. angle steel
- B21B1/085—Rail sections
-
- 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
- C21D2211/009—Pearlite
-
- 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
- C21D2221/00—Treating localised areas of an article
-
- 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
- C21D2221/00—Treating localised areas of an article
- C21D2221/02—Edge parts
Definitions
- the present invention relates to an internal high hardness type pearlitic rail with excellent wear resistance and rolling contact fatigue (RCF) resistance and a method for producing the same.
- the present invention relates to an internal high hardness type pearlitic rail having excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties and achieving longer operating life of rails used under severe high-axle load conditions like foreign mining railways in which freight cars are heavy and high curve lines are often present, and to a method for producing the internal high hardness type pearlitic rail.
- High-axle load railways are used to indicate railways in which trains and freight cars have a large carrying capacity (for example, a carrying capacity of about 150 ton or more per freight car).
- a portion located from the surface of corners and of the top of the head of the rail to a depth of at least 20 mm have a hardness of 370HV or more, thereby improving the operating life of the rail.
- a portion located from the surface of corners and of the top of the head of the rail to a depth of at least 20 mm have a hardness of 300HV to 500HV, thereby improving the operating life of the rail.
- Japanese Patent No. 3648192 and Japanese Unexamined Patent Application Publication No. 5-287450 disclose a technique for improving delayed fracture properties by subjecting high-strength pearlitic steel to heavy drawing.
- the use of heavy drawing increases the production cost of rails.
- A-type inclusions are controlled so as to have a size of 0.1 to 20 ⁇ m and in such a manner that the number of the A-type inclusions is 25 to 11,000 per square millimeter, thereby improving the toughness and ductility of a rail.
- this technique does not necessarily provide satisfactory delayed fracture properties.
- the present invention also provides a preferred method for producing the internal high hardness type pearlitic rail
- the inventors have produced pearlitic rails with different proportions of Si, Mn, Cr, V, and N and have conducted intensive studies on the structure, hardness, wear resistance, rolling contact fatigue resistance, and delayed fracture properties.
- the inventors have found that in the case where the value of [%Mn]/[%Cr], which is calculated from the Mn content [%Mn] and the Cr content [%Cr], is greater than or equal to 0.3 and less than 1.0 and where the value of [%V]/[%N], which is calculated from the V content [%V] and the N content [%N], is in the range of 8.0 to 30.0, the spacing of the lamella (lamellar spacing) of a pearlite layer (hereinafter, also referred to simply as a "lamella”) is reduced, and the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than
- the inventors have found that in the case where the quench hardenability index (i.e., the DI value) is in the range of 5.6 to 8.6, the carbon equivalent (i.e., the C eq value) is in the range of 1.04 to 1.27, and the value of [%Si] + [%Mn] + [%Cr], which is calculated from the Mn content [%Mn], the Cr content [%Cr], and the Si content [%Si], is in the range of 1.55% to 2.50% by mass, the effect of improving wear resistance and rolling contact fatigue resistance can be stably maintained.
- the quench hardenability index i.e., the DI value
- the carbon equivalent i.e., the C eq value
- the value of [%Si] + [%Mn] + [%Cr] which is calculated from the Mn content [%Mn], the Cr content [%Cr], and the Si content [%Si]
- the present invention has been accomplished on the basis of these findings.
- an internal high hardness type pearlitic rail with excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, 0.005% to 0.12% by mass V, 0.0015% to 0.0060% by mass N, and the balance being Fe and incidental impurities, in which the value of [%Mn]/[%Cr] is greater than or equal to 0.3 and less than 1.0, where [%Mn] represents the Mn content, and [%Cr] represents the Cr content, and the value of [%V]/[%N] is in the range of 8.0 to 30.0, where [%V] represents the V content, and [%N] represents the N content, and in which the internal hardness of a rail head is defined by the Vickers hardness of a portion located from a
- the value of DI calculated from expression (1) is in the range of 5.6 to 8.6, and the value of C eq calculated from expression (2) is in the range of 1.04 to 1.27
- DI 0.548 ⁇ % C 1 / 2 ⁇ 1 + 0.64 % Si ⁇ 1 + 4.1 % Mn ⁇ 1 + 2.83 % P ⁇ 1 - 0.62 % S ⁇ 1 + 2.23 % Cr ⁇ 1 + 1.82 % V
- C eq % C + % Si / 11 + % Mn / 7 + % Cr / 5.8 + % V
- [%C] represents the C content
- [%Si] represents the Si content
- [%Mn] represents the Mn content
- [%P] represents the P content
- [%S] represents the S content
- [%Cr] represents the Cr content
- [%V] represents the V content of the composition.
- the value of [%Si] + [%Mn] + [%Cr] is in the range of 1.55% to 2.50, where [%Si] represents the Si content, [%Mn] represents the Mn content, and [%Cr] represents the Cr content of the composition.
- the composition further contains one or two or more selected from 1.0% by mass or less Cu, 1.0% by mass or less Ni, 0.001% to 0.05% by mass Nb, and 0.5% by mass or less Mo.
- the lamellar spacing of a pearlite layer in the portion located from the surface layer of the rail head to a depth of at least 25 mm is in the range of 0.04 to 0.15 ⁇ m.
- a method for producing an internal high hardness type pearlitic rail with excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties includes hot-rolling a steel material having the composition described above to form a rail in such a manner that the finishing rolling temperature is in the range of 850°C to 950°C, and then slack-quenching the surface of the railhead from a temperature equal to or higher than a pearlite transformation starting temperature to 400°C to 650°C at a cooling rate of 1.2 to 5 °C/s.
- a pearlitic rail having excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties can be stably produced compared with pearlitic rails in the related art. This contributes to longer operating life of pearlitic rails used for high-axle load railways and to the prevention of railway accidents, providing industrially beneficial effects.
- C is an essential element to form cementite in a pearlitic structure to ensure wear resistance.
- the wear resistance is improved as the C content is increased.
- a C content of less than 0.73% by mass however, it is difficult to provide high wear resistance compared with heat treatment-type pearlitic rails in the conventional art.
- a C content exceeding 0.85% by mass results in the formation of proeutectoid cementite in austenite grain boundaries during transformation after hot rolling, thereby significantly reducing rolling contact fatigue resistance.
- the C content is set in the range of 0.73% to 0.85% by mass and preferably 0.75% to 0.85% by mass.
- Si is an element serving as a deoxidizer and strengthening a pearlitic structure and needed in an amount of 0.5% by mass or more.
- a Si content exceeding 0.75% by mass results in a deterioration in weldability due to high bond strength of Si with oxygen. Further more, high quench hardenability of Si facilitates the formation of a martensitic structure in a surface layer of the internal high hardness type pearlitic rail.
- the Si content is set in the range of 0.5% to 0.75% by mass and preferably 0.5% to 0.70% by mass.
- Mn reduces a pearlite transformation starting temperature to reduce a lamellar spacing.
- Mn contributes to higher strength and higher ductility of the internal high hardness type pearlitic rail.
- An excessive amount of Mn added reduces the equilibrium transformation temperature of pearlite to reduce the degree of supercooling, increasing the lamellar spacing.
- a Mn content of less than 0.3% by mass does not result in a sufficient effect.
- a Mn content exceeding 1.0% by mass facilitates the formation of a martensitic structure, so that hardening and embrittlement occur during heat treatment and welding, thereby readily reducing the quality of the material.
- the equilibrium transformation temperature is reduced, thereby increasing the lamellar spacing.
- the Mn content is set in the range of 0.3% to 1.0% by mass and preferably 0.3% to 0.8% by mass.
- the P content is set to 0.035% by mass or less and preferably 0.020% by mass or less.
- S is present in steel mainly in the form of A-type inclusions.
- a S content exceeding 0.012% by mass results in a significant increase in the amount of the inclusions and also results in the formation of coarse inclusions, thereby reducing cleanliness of steel.
- a S content of less than 0.0005% by mass leads to an increase in steelmaking cost.
- the S content is set in the range of 0.0005% to 0.012% by mass and preferably 0.0005% to 0.008% by mass.
- Cr is an element that increases the equilibrium transformation temperature of pearlite to contribute to a reduction in lamellar spacing and that further increases the strength by solid-solution hardening.
- a Cr content of less than 0.2% by mass does not result in sufficient internal hardness.
- a Cr content exceeding 1.3% by mass results in excessively high quench hardenability, forming martensite to reduce wear resistance and rolling contact fatigue resistance.
- the Cr content is set in the range of 0.2% to 1.3% by mass, preferably 0.3% to 1.3% by mass, and more preferably 0.5% to 1.3% by mass.
- V 0.005% to 0.12% by mass
- V forms a carbonitride that is dispersively precipitated in a matrix, improving wear resistance and delayed fracture properties.
- a V content of less than 0.005% by mass the effect is reduced.
- a V content exceeding 0.12% by mass results in an increase in alloy cost, thereby increasing the cost of the internal high hardness type pearlitic rail.
- the V content is in the range of 0.005% to 0.12% by mass and preferably 0.012% to 0.10% by mass.
- N forms a nitride that is dispersively precipitated in a matrix, improving wear resistance and delayed fracture properties.
- a N content of less than 0.0015% by mass the effect is reduced.
- a N content exceeding 0.0060% by mass results in the formation of coarse nitrides in the internal high hardness type pearlitic rail, thereby reducing rolling contact fatigue resistance and delayed fracture properties.
- the N content is in the range of 0.0015% to 0.060% by mass and preferably 0.0030% to 0.0060%.
- Mn and Cr are additive elements in order to increase the hardness of the internal high hardness type pearlitic rail.
- martensite is formed in a surface layer of the internal high hardness type pearlitic rail.
- the units of [%Mn] and [%Cr] are percent by mass.
- the Cr content is high. This facilitates the formation of martensite in the surface layer of the internal high hardness type pearlitic rail due to high quench hardenability of Cr.
- the value of [%Mn]/[%Cr] is 1.0 or more, the Mn content is high.
- the internal hardness of the head of the rail (hardness of a portion located from the surface layer of the head of the internal high hardness type pearlitic rail to a depth of at least 25 mm) can be controlled within a range described below while the formation of martensite in the surface layer is being prevented.
- the value of [%Mn]/[%Cr] is greater than or equal to 0.3 and less than 1.0 and preferably in the range of 0.3 to 0.9.
- V and N are important elements that form a V-based nitride serving as a hydrogen-trapping site.
- the amounts thereof added must be controlled.
- the units of [%V] and [%N] are percent by mass.
- the [%V]/[%N] value is less than 8.0, the V-based nitride is not sufficiently formed, thereby reducing the number of the hydrogen-trapping sites. Thus, it is unlikely that delayed fracture properties will be significantly improved.
- the [%V]/[%N] value exceed 30.0, the amount of V added is increased to increase the alloy cost, thereby increasing the cost of the internal high hardness type pearlitic rail. Furthermore, it is unlikely that delayed fracture properties will be significantly improved.
- the [%V]/[%N] value is in the range of 8.0 to 30.0 and preferably 8.0 to 22.0.
- Internal hardness of rail head (hardness of portion located from surface layer of head of internal high hardness type pearlitic rail to depth of at least 25 mm): greater than or equal to 380Hv and less than 480Hv
- An internal hardness of the rail head of less than 380Hv results in a reduction in wear resistance, thereby reducing the operating life of the internal high hardness type pearlitic rail.
- An internal hardness of the rail head of 480Hv or more results in the formation of martensite, thereby reducing the rolling contact fatigue resistance of the internal high hardness type pearlitic rail.
- the internal hardness of the rail head is greater than or equal to 380Hv and less than 480Hv.
- the reason the internal hardness of the rail head is defined by the hardness of the portion located from the surface layer of the head of the internal high hardness type pearlitic rail to a depth of at least 25 mm is as follows: at a depth of less than 25 mm, the wear resistance of the internal high hardness type pearlitic rail is reduced with increasing distance from the surface layer of the rail head toward the inside, reducing the operating life.
- the internal hardness of the rail head is greater than 390Hv and less than 480Hv.
- DI 0.548 ⁇ % C 1 / 2 ⁇ 1 + 0.64 % Si ⁇ 1 + 4.1 % Mn ⁇ 1 + 2.83 % P ⁇ 1 - 0.62 % S ⁇ 1 + 2.23 % Cr ⁇ 1 + 1.82 % V
- [%C] represents the C content
- [%Si] represents the Si content
- [%Mn] represents the Mn content
- [%P] represents the P content
- [%S] represents the S content
- [%Cr] represents the Cr content
- [%V] represents the V content. Note that the units of [%C], [%Si], [%Mn], [%P], [%S], [%Cr], and [%V] are percent by mass.
- the DI value indicates quench hardenability and is used as an index to determine whether quench hardenability is good or not.
- the DI value is used as an index to prevent the formation of martensite in the surface layer of the internal high hardness type pearlitic rail and to achieve a target value of the internal hardness of the rail head.
- the DI value is preferably maintained within a suitable range. At a DI value of less than 5.6, although a desired internal hardness is provided, the internal hardness is close to the lower limit of the target hardness range. Thus, it is unlikely that the wear resistance, rolling contact fatigue resistance, and delayed fracture properties will be further improved.
- a DI value exceeding 8.6 results in an increase in the quench hardenability of the internal high hardness type pearlitic rail, facilitating the formation of martensite in the surface layer of the rail head.
- the DI value is preferably in the range of 5.6 to 8.6 and more preferably 5.6 to 8.2.
- C eq % C + % Si / 11 + % Mn / 7 + % Cr / 5.8 + % V
- [%C] represents the C content
- [%Si] represents the Si content
- [%Mn] represents the Mn content
- [%Cr] represents the Cr content
- [%V] represents the V content. Note that the units of [%C], [%Si], [%Mn], [%Cr], and [%V] are percent by mass.
- the C eq value is used to estimate the maximum hardness and weldability from proportions of the alloy components added.
- the C eq value is used as an index to prevent the formation of martensite in the surface layer of the internal high hardness type pearlitic rail and to achieve a target value of the internal hardness of the rail head.
- the C eq value is preferably maintained within a suitable range. At a C eq value of less than 1.04, although a desired internal hardness is provided, the internal hardness is close to the lower limit of the target hardness range. Thus, it is unlikely that the wear resistance and rolling contact fatigue resistance will be further improved.
- a C eq value exceeding 1.27 results in an increase in the quench hardenability of the internal high hardness type pearlitic rail, facilitating the formation of martensite in the surface layer of the rail head.
- the C eq value is preferably in the range of 1.04 to 1.27 and more preferably 1.04 to 1.20.
- the value of [%Si] + [%Mn] + [%Cr] is preferably in the range of 1.55 to 2.50 and more preferably 1.55 to 2.30.
- the units of [%Si], [%Mn], and [%Cr] are percent by mass.
- composition described above may further contain one or two or more selected from 1.0% by mass or less Cu, 1.0% by mass or less Ni, 0.001% to 0.05% by mass Nb, and 0.5% by mass or less Mo, as needed.
- Cu is an element that further increases the strength by solid-solution hardening.
- the Cu content is preferably 0.005% by mass or more.
- the Cu content is preferably 1.0% by mass or less and more preferably 0.005% to 0.5% by mass.
- Ni is an element that increases the strength without reducing ductility. Furthermore, the addition of Ni together with Cu suppresses Cu cracking. Thus, when Cu is added, preferably, Ni is also added. To provide the effect, the Ni content is preferably 0.005% or more. The Ni content exceeding 1.0% by mass, however, results in an increase in quench hardenability, forming martensite. This is liable to cause a reduction in wear resistance and rolling contact fatigue resistance. In the case where Ni is added, thus, the Ni content is preferably 1.0% by mass or less and more preferably 0.005% to 0.5% by mass.
- Nb is combined with C in steel to precipitate as a carbide during and after rolling and contributes to a reduction in pearlite colony size. This leads to significant improvement in wear resistance, rolling contact fatigue resistance and ductility and significant contribution to longer operating life of the internal high hardness type pearlitic rail.
- a Nb content of 0.001% by mass or more is preferred. At a Nb content of less than 0.001% by mass, the effect is not sufficiently provided. At a Nb content exceeding 0.05% by mass, the effect of improving wear resistance and rolling contact fatigue resistance is saturated, the effect is not worth the amount added.
- the Nb content is preferably in the range of 0.001% to 0.05% by mass and more preferably 0.001% to 0.03% by mass.
- Mo is an element that increases the strength by solid-solution hardening.
- the Mn content is preferably 0.005% by mass or more.
- a Mo content exceeding 0.5% by mass is liable to cause the formation of a bainitic structure and to reduce wear resistance.
- the Mo content is preferably 0.5% by mass or less and more preferably 0.005% to 0.3% by mass.
- a reduction in the lamellar spacing of a pearlite layer increases the hardness of the internal high hardness type pearlitic rail, which is advantageous from the viewpoint of improving wear resistance and rolling contact fatigue resistance.
- a lamellar spacing exceeding 0.15 ⁇ m does no result in sufficient improvement in these properties.
- the lamellar spacing is preferably 0.15 ⁇ m or less.
- a technique for reducing the lamellar spacing by improving quench hardenability is to be used. This is liable to cause the formation of martensite in the surface layer, thereby adversely affecting rolling contact fatigue resistance.
- the lamellar spacing is preferably 0.04 ⁇ m or more.
- the present invention also includes a pearlitic rail containing other trace elements in place of part of the balance Fe in a composition according to the present invention to the extent that the effect of the present invention is not substantially affected.
- impurities include P and O.
- a P content of up to 0.035% by mass is allowable as described above.
- An O content of up to 0.004% by mass is allowable.
- a Ti content of up to 0.0010% is allowable, Ti being contained as an impurity.
- Ti forms an oxide to reduce rolling contact fatigue resistance, which is a basic property of the rail.
- the Ti content is preferably controlled so as to be up to 0.0010%.
- the internal high hardness type pearlitic rail of the present invention is preferably produced by hot-rolling a steel material with a composition according to the present invention to form a rail shape in such a manner that the finishing rolling temperature is in the range of 850°C to 950°C, and slack-quenching at least the head of the rail article from a temperature equal to or higher than a pearlite transformation starting temperature to 400°C to 650°C at a cooling rate of 1.2 to 5 °C/s.
- finishing rolling temperature roll finishing temperature
- a cooling rate of the slack quenching 1.2 to 5 °C/s
- a cooling stop temperature 400°C to 650°C
- Finishing rolling temperature 850°C to 950°C
- finishing rolling temperature In the case of a finishing rolling temperature of less than 850°C, rolling is performed to a low-temperature austenite range. This not only introduces processing strain in austenite grains but also causes a significantly high degree of extension of austenite grains.
- the introduction of dislocation and an increase in austenite grain boundary area result in an increase in the number of pearlite nucleation sites.
- the pearlite colony size is reduced, the increase in the number of pearlite nucleation sites increases a pearlite transformation starting temperature, thereby increasing the lamellar spacing of the pearlite layer to cause a significant reduction in wear resistance.
- a finishing rolling temperature exceeding 950°C increases the austenite grain size, thereby increasing the final pearlite colony size to cause a reduction in rolling contact fatigue resistance.
- the finishing rolling temperature is preferably in the range of 850°C to 950°C.
- a cooling rate of less than 1.2 °C/s results in an increase in pearlite transformation starting temperature, thereby increasing the lamellar spacing of the pearlite layer to cause a significant reduction in wear resistance and rolling contact fatigue resistance. Meanwhile, a cooling rate exceeding 5 °C/s results in the formation of a martensitic structure, thereby reducing ductility and toughness.
- the cooling rate is preferably in the range of 1.2 to 5 °C/s and more preferably 1.2 to 4.6 °C/s.
- the pearlite transformation starting temperature varies depending on the cooling rate, the present invention, the pearlite transformation starting temperature is referred to as an equilibrium transformation temperature in the present invention. In the composition range of the present invention, the cooling rate within the above range may be used at 720°C or higher.
- Cooling stop temperature 400°C to 650°C
- the cooling stop temperature is preferably in the range of 400°C to 650°C and more preferably 450°C to 650°C.
- the internal high hardness type pearlitic rail is actually placed and evaluated. In this case, disadvantageously, it takes a long time to conduct a test.
- evaluation is made by a comparative test performed under simulated real conditions of rail and wheel contact with a Nishihara-type rolling contact test machine that can evaluate wear resistance in a short time.
- a Nishihara-type rolling contact test piece 1 having an external diameter of 30 mm is taken from the rail head. The test is performed by contacting the test piece 1 with a tire specimen 2 and rotating them as shown in Fig. 1 . Arrows in Fig. 1 indicate rotational directions of the Nishihara-type rolling contact test piece 1 and the tire specimen 2.
- a round bar with a diameter of 32 mm is taken from the head of a standard rail (Japanese industrial standard rail) described in JIS E1101.
- the round bar is subjected to heat treatment so as to have a Vickers hardness of 390HV (load: 98 N) and a tempered martensitic structure.
- the round bar is processed so as to have a shape shown in Fig. 1 , resulting in the tire specimen.
- the Nishihara-type rolling contact test piece 1 is taken from each of two portions of a rail head 3 as shown in Fig. 2 .
- a piece taken from a surface layer of the rail head 3 is referred to as a Nishihara-type rolling contact test piece 1a.
- a piece taken from the inside is referred to as a Nishihara-type rolling contact test piece 1b.
- the center of the Nishihara-type rolling contact test piece 1b, which is taken from the inside of the rail head 3, in the longitudinal direction is located at a depth of 24 to 26 mm (mean value: 25 mm) below the top face of the rail head 3.
- the test is performed in a dry state at a contact pressure of 1.4 GPa, a slip ratio of -10%, and a rotation speed of 675 rpm (750 rpm for the tire specimen).
- the wear amount at 100,000 rotations is measured.
- a heat-treated pearlitic rail is employed as reference steel used in comparing wear amounts. It is determined that the wear resistance is improved when the wear amount is at least 10% smaller than that of the reference steel. Note that the rate of improvement in wear resistance is calculated from ⁇ (wear amount of reference steel - wear amount of test piece)/(wear amount of reference steel) ⁇ ⁇ 100.
- the Nishihara-type rolling contact test piece 1 having an external diameter of 30 mm and a curved contact surface with a radius of curvature of 15 mm is taken from the rail head.
- a test is performed by contacting the test piece 1 with the tire specimen 2 and rotating them as shown in Fig. 3 .
- Arrows in Fig. 3 indicate rotational directions of the Nishihara-type rolling contact test piece 1 and the tire specimen 2.
- the Nishihara-type rolling contact test piece 1 is taken from each of two portions of a rail head 3 as shown in Fig. 2 .
- the tire specimen and each portion where the Nishihara-type rolling contact test piece 1 is taken are the same as above; hence, the description is omitted.
- the test is performed under an oil-lubricated condition at a contact pressure of 2.2 GPa, a slip ratio of -20%, and a rotation speed of 600 rpm (750 rpm for the tire specimen).
- the surface of each test piece is observed every 25,000 rotations.
- the number of rotations at the occurrence of a crack with a length of 0.5 mm or more is defined as rolling contact fatigue life.
- a heat-treated pearlitic rail is employed as reference steel used in comparing rolling contact fatigue life. It is determined that the rolling contact fatigue resistance is improved when the rolling contact fatigue life is at least 10% longer than that of the reference steel.
- the rate of improvement in rolling contact fatigue resistance is calculated from ⁇ (number of rotations at occurrence of fatigue damage of test piece - number of rotation at occurrence of fatigue damage of reference steel)/(number of rotations at occurrence of fatigue damage of reference steel) ⁇ ⁇ 100.
- a slow strain rate technique (SSRT) test piece 4 having the center 25.4 mm below the top face of the rail head 3 is taken.
- the SSRT test piece 4 has dimensions and a shape shown in Fig. 5 .
- the test piece is subjected to three triangle mark finish, except for screw sections and round sections. Parallel sections are polished with emery paper (up to #600).
- the SSRT test piece is mounted on an SSRT test apparatus and then subjected to an SSRT test at a strain rate of 3.3 ⁇ 10 -6 /s and a temperature of 25°C in the atmosphere, obtaining elongation E 0 of the SSRT test piece in the atmosphere.
- An SSRT test piece is subjected to an SSRT test in a 20 mass% ammonium thiocyanate (NH 4 SCN) solution at a strain rate of 3.3 ⁇ 10 -6 /s and a temperature of 25°C, obtaining elongation E 1 of the SSRT test piece in the ammonium thiocyanate solution.
- Delayed fracture susceptibility i.e., DF
- DF Delayed fracture susceptibility
- the delayed fracture properties are improved when the rate of improvement in delayed fracture susceptibility is at least 10% higher than that of a reference steel (i.e., a heat treatment-type pearlitic rail having a C content of 0.68% by mass). Note that the rate of improvement in delayed fracture susceptibility is calculated from ⁇ (delayed fracture susceptibility of test piece - delayed fracture susceptibility of reference steel)/(delayed fracture susceptibility of reference steel ⁇ ⁇ 100.
- the Vickers hardness of a portion located from the surface layer of the rail head of to a depth of 25 mm is measured at a load of 98 N and a pitch of 1 mm.
- the minimum hardness value is defined as the internal hardness of the rail head.
- Random five fields of view of each of a portion (at a depth of about 1 mm) close to the surface layer of the rail head and a portion located at a depth of 25 mm are observed with a scanning electron microscope (SEM) at a magnification of 7,500X.
- SEM scanning electron microscope
- the portion is observed at a magnification of 20,000X, and the lamellar spacing in the field of view is measured.
- the measurement is performed in another field of view.
- the lamellar spacing is evaluated by the mean value of the lamellar spacing measurements in the five fields of view.
- the finishing rolling temperature shown in Table 2 indicates a value obtained by measuring a temperature of the surface layer of a side face of each rail head on the entrance side of a final roll mill with a radiation thermometer.
- the cooling stop temperature indicates a value obtained by measuring a temperature of the surface layer of a side face of each rail head on the exit side of a cooling apparatus with a radiation thermometer.
- the cooling rate was defined as the rate of change in temperature between the start and end of cooling.
- a pearlitic rail having excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties compared with pearlitic rails in the related art can be stably produced. This contributes to longer operating life of pearlitic rails used for high-axle load railways and to the prevention of railway accidents, providing industrially beneficial effects.
- a pearlitic rail having excellent wear resistance, rolling contact fatigue resistance, and delayed fracture properties compared with pearlitic rails in the related art can be stably produced. This contributes to longer operating life of pearlitic rails used for high-axle load railways and to the prevention of railway accidents, providing industrially beneficial effects.
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- Organic Chemistry (AREA)
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Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2007264826 | 2007-10-10 | ||
PCT/JP2008/056273 WO2009047926A1 (fr) | 2007-10-10 | 2008-03-25 | Rail en acier perlitique à dureté interne élevée dont la résistance à l'usure, à la rupture par fatigue et à la fracture retardée sont excellentes ainsi que son procédé de fabrication |
Publications (3)
Publication Number | Publication Date |
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EP2196552A1 true EP2196552A1 (fr) | 2010-06-16 |
EP2196552A4 EP2196552A4 (fr) | 2015-12-23 |
EP2196552B1 EP2196552B1 (fr) | 2017-05-10 |
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Application Number | Title | Priority Date | Filing Date |
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EP08739390.6A Active EP2196552B1 (fr) | 2007-10-10 | 2008-03-25 | Rail en acier perlitique à dureté interne élevée dont la résistance à l'usure, à la rupture par fatigue et à la fracture retardée sont excellentes ainsi que son procédé de fabrication |
Country Status (7)
Country | Link |
---|---|
US (1) | US20100186857A1 (fr) |
EP (1) | EP2196552B1 (fr) |
JP (1) | JP5292875B2 (fr) |
CN (1) | CN101743334B (fr) |
AU (1) | AU2008310503B2 (fr) |
CA (1) | CA2687438C (fr) |
WO (1) | WO2009047926A1 (fr) |
Cited By (4)
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US8241442B2 (en) | 2009-12-14 | 2012-08-14 | Arcelormittal Investigacion Y Desarrollo, S.L. | Method of making a hypereutectoid, head-hardened steel rail |
CN105838981A (zh) * | 2016-05-20 | 2016-08-10 | 金轮针布(江苏)有限公司 | 一种针布用钢 |
EP2980231A4 (fr) * | 2013-03-27 | 2016-12-21 | Jfe Steel Corp | Rail en perlite et procédé permettant de fabriquer un rail en perlite |
CN112501417A (zh) * | 2020-11-16 | 2021-03-16 | 攀钢集团攀枝花钢铁研究院有限公司 | 一种重载铁路用钢轨及其制备方法 |
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JP6164356B2 (ja) * | 2014-02-26 | 2017-07-19 | 新日鐵住金株式会社 | 鉄道用車軸 |
US9670570B2 (en) | 2014-04-17 | 2017-06-06 | Evraz Inc. Na Canada | High carbon steel rail with enhanced ductility |
CA2946548C (fr) * | 2014-05-29 | 2018-11-20 | Nippon Steel & Sumitomo Metal Corporation | Rail et son procede de fabrication |
BR112016028776A2 (pt) * | 2014-06-11 | 2017-08-22 | Jfe Steel Corp | roda para veículo ferroviário e método de fabricação de roda para veículo ferroviário |
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CN104213037A (zh) * | 2014-09-07 | 2014-12-17 | 钢铁研究总院 | 一种高氮珠光体钢 |
AU2016210107B2 (en) * | 2015-01-23 | 2018-10-18 | Nippon Steel Corporation | Rail |
CN105154773B (zh) * | 2015-07-23 | 2017-03-08 | 攀钢集团攀枝花钢铁研究院有限公司 | 一种重载铁路用钢轨及其生产方法和应用 |
CN104988405B (zh) * | 2015-07-23 | 2017-03-08 | 攀钢集团攀枝花钢铁研究院有限公司 | 一种客货混运用钢轨及其生产方法和应用 |
CN105112786B (zh) * | 2015-09-29 | 2017-04-12 | 燕山大学 | 一种超级珠光体钢轨钢及其制备方法 |
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CA3054645C (fr) | 2017-03-21 | 2021-10-19 | Jfe Steel Corporation | Rail, et procede de fabrication de celui-ci |
CA3054643C (fr) | 2017-03-21 | 2021-09-28 | Jfe Steel Corporation | Procede de fabrication de rail |
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EP3778955A4 (fr) * | 2018-03-30 | 2021-05-05 | JFE Steel Corporation | Rail |
JP6852761B2 (ja) * | 2018-10-26 | 2021-03-31 | Jfeスチール株式会社 | レールおよびその製造方法 |
WO2024134875A1 (fr) * | 2022-12-23 | 2024-06-27 | 日本製鉄株式会社 | Rail |
CN116695001A (zh) * | 2023-06-30 | 2023-09-05 | 武汉钢铁有限公司 | 提高重轨钢抗延迟开裂性能的制造方法 |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3846183A (en) * | 1973-05-02 | 1974-11-05 | Bethlehem Steel Corp | Method of treating steel rail |
JPS5818966B2 (ja) * | 1978-06-23 | 1983-04-15 | 日本鋼管株式会社 | レ−ルの製造方法 |
JPH05171268A (ja) * | 1991-09-27 | 1993-07-09 | Nippon Steel Corp | 高靭性パーライト鋼の製造法 |
JPH06279928A (ja) * | 1993-03-29 | 1994-10-04 | Nippon Steel Corp | 靭性および延性に優れた高強度レールおよびその製造法 |
JP3731934B2 (ja) * | 1996-03-11 | 2006-01-05 | 新日本製鐵株式会社 | 高深度高強度レールの製造法 |
JPH10195601A (ja) * | 1996-12-27 | 1998-07-28 | Nippon Steel Corp | 耐摩耗性・耐内部疲労損傷性に優れたパーライト系レールおよびその製造法 |
JP2000129397A (ja) * | 1998-10-30 | 2000-05-09 | Nkk Corp | 耐摩耗性と延性に優れたパーライト型レール |
JP4571759B2 (ja) * | 2001-06-01 | 2010-10-27 | 新日本製鐵株式会社 | パーライト系レールおよびその製造方法 |
JP4272385B2 (ja) * | 2002-04-05 | 2009-06-03 | 新日本製鐵株式会社 | 耐摩耗性および延性に優れたパーライト系レール |
JP4469248B2 (ja) * | 2004-03-09 | 2010-05-26 | 新日本製鐵株式会社 | 耐摩耗性および延性に優れた高炭素鋼レールの製造方法 |
CN100443617C (zh) * | 2005-12-29 | 2008-12-17 | 攀枝花钢铁(集团)公司 | 珠光体类热处理钢轨及其生产方法 |
-
2008
- 2008-03-25 JP JP2008077914A patent/JP5292875B2/ja active Active
- 2008-03-25 WO PCT/JP2008/056273 patent/WO2009047926A1/fr active Application Filing
- 2008-03-25 EP EP08739390.6A patent/EP2196552B1/fr active Active
- 2008-03-25 CN CN2008800203846A patent/CN101743334B/zh active Active
- 2008-03-25 CA CA2687438A patent/CA2687438C/fr active Active
- 2008-03-25 AU AU2008310503A patent/AU2008310503B2/en active Active
- 2008-03-25 US US12/663,866 patent/US20100186857A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
---|
See references of WO2009047926A1 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
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US8241442B2 (en) | 2009-12-14 | 2012-08-14 | Arcelormittal Investigacion Y Desarrollo, S.L. | Method of making a hypereutectoid, head-hardened steel rail |
US8721807B2 (en) | 2009-12-14 | 2014-05-13 | Arcelormittal Investigacion Y Desarrollo, S.L. | Hypereutectoid, head-hardened steel rail |
US9512501B2 (en) | 2009-12-14 | 2016-12-06 | Arcelormittal Investigacion Y Desarrollo, S.L. | Hypereutectoid-head steel rail |
EP2980231A4 (fr) * | 2013-03-27 | 2016-12-21 | Jfe Steel Corp | Rail en perlite et procédé permettant de fabriquer un rail en perlite |
US10253397B2 (en) | 2013-03-27 | 2019-04-09 | Jfe Steel Corporation | Pearlitic rail and method for manufacturing pearlitic rail |
CN105838981A (zh) * | 2016-05-20 | 2016-08-10 | 金轮针布(江苏)有限公司 | 一种针布用钢 |
CN112501417A (zh) * | 2020-11-16 | 2021-03-16 | 攀钢集团攀枝花钢铁研究院有限公司 | 一种重载铁路用钢轨及其制备方法 |
CN112501417B (zh) * | 2020-11-16 | 2022-05-24 | 攀钢集团攀枝花钢铁研究院有限公司 | 一种重载铁路用钢轨及其制备方法 |
Also Published As
Publication number | Publication date |
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AU2008310503A1 (en) | 2009-04-16 |
CA2687438C (fr) | 2012-12-18 |
CN101743334B (zh) | 2012-04-04 |
AU2008310503B2 (en) | 2010-12-09 |
JP5292875B2 (ja) | 2013-09-18 |
US20100186857A1 (en) | 2010-07-29 |
EP2196552B1 (fr) | 2017-05-10 |
JP2009108396A (ja) | 2009-05-21 |
CN101743334A (zh) | 2010-06-16 |
CA2687438A1 (fr) | 2009-04-16 |
EP2196552A4 (fr) | 2015-12-23 |
WO2009047926A1 (fr) | 2009-04-16 |
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