EP3124636B1 - Rail and method for manufacturing same - Google Patents

Rail and method for manufacturing same Download PDF

Info

Publication number
EP3124636B1
EP3124636B1 EP15768893.8A EP15768893A EP3124636B1 EP 3124636 B1 EP3124636 B1 EP 3124636B1 EP 15768893 A EP15768893 A EP 15768893A EP 3124636 B1 EP3124636 B1 EP 3124636B1
Authority
EP
European Patent Office
Prior art keywords
less
rail
rolling
cooling
hardness
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.)
Active
Application number
EP15768893.8A
Other languages
German (de)
French (fr)
Other versions
EP3124636A4 (en
EP3124636B2 (en
EP3124636A1 (en
Inventor
Tatsumi Kimura
Yukio Takashima
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
JFE 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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=54194697&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP3124636(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Publication of EP3124636A4 publication Critical patent/EP3124636A4/en
Publication of EP3124636A1 publication Critical patent/EP3124636A1/en
Publication of EP3124636B1 publication Critical patent/EP3124636B1/en
Application granted granted Critical
Publication of EP3124636B2 publication Critical patent/EP3124636B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/04Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rails
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/002Heat treatment of ferrous alloys containing Cr
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/005Heat treatment of ferrous alloys containing Mn
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D6/00Heat treatment of ferrous alloys
    • C21D6/008Heat treatment of ferrous alloys containing Si
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/002Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/06Ferrous alloys, e.g. steel alloys containing aluminium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/26Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/28Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/34Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/38Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/18Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium

Definitions

  • the present disclosure relates to a rail, particularly a rail having high hardness and small hardness variation, and also to a method for manufacturing the rail.
  • Freight cars used on freight transportation and mining railways tend to have heavier loading weights than passenger cars, which results in heavy loads acting on the axles of the freight cars and a severe contact environment between the freight car wheels and rails. Rails used under these conditions are expected to exhibit wear resistance and are conventionally made from steel having a pearlite structure.
  • PTL 8 proposes a method for manufacturing a high hardness rail having superior head internal fatigue resistance.
  • finish rolling is performed at a head surface temperature of 850°C to 1050°C to leave final finishing, and after a time interval between passes of at least 3 seconds and no greater than 1 minute, one pass or a plurality of passes of final finish rolling are performed at a head surface temperature of 800°C to 950°C and with a rolling reduction of 10% or less per pass.
  • PTL 9 describes a method for manufacturing a high toughness rail that exhibits a pearlite metal structure.
  • this method after rough rolling of a steel slab of low-alloy steel or carbon steel containing 0.60% to 1.00% of C into a rail shape, continuous finish rolling is performed for three or more rolling passes at a rail surface temperature of 850°C to 1000°C with a cross-section area reduction rolling reduction of 5% to 30% per pass and 10 seconds or less between rolling passes, and thereafter the rail is allowed to cool or is cooled from 700°C or higher to a temperature in a range of 500°C to 700°C at a rate of 2°C/s to 15°C/s.
  • PTL 10 discloses a method for manufacturing a pearlitic rail having superior wear resistance and ductility in which at least rough rolling and finish rolling are performed on a steel slab for rail rolling that contains, in mass%, 0.65% to 1.20% of C, 0.05% to 2.00% of Si, and 0.05% to 2.00% of Mn, the balance being Fe and incidental impurities.
  • Rails used in high axle load railways are expected to have superior wear resistance in order to improve rail durability and, in response, there have been various proposals for rails, such as described above, that focus on increasing hardness.
  • a rail is manufactured by hot rolling a steel raw material to a length of as long as 100 m or greater and, hardness of the rail exhibits variation in the rail length direction that is dependent on the method of manufacture. Consequently, the rail may experience uneven wear when laid and thus may be unable to sufficiently demonstrate its effects. Although it is extremely important, therefore, to reduce hardness variation in the longitudinal direction of rolling, PTL 1-10 make no mention of this hardness variation.
  • an objective of the present disclosure is to provide a rail that exhibits excellent wear resistance and reduced hardness variation in the rail length direction, and also a method for manufacturing the rail.
  • the inventors sampled test pieces from steel materials having pearlite structures corresponding to rails of differing hardness and conducted a rail wear test with respect to the test pieces in order to investigate a relationship between hardness and wear. The results of the investigation are shown in FIG. 1 .
  • Nishihara type wear test pieces 1 were sampled from two locations in a rail head 3 as illustrated in FIG. 3 .
  • a test piece sampled from a surface layer of the rail head 3 is denoted Nishihara type wear test piece 1a and a test piece sampled from an inner part of the rail head 3 is denoted Nishihara type wear test piece 1b.
  • the center, in a longitudinal direction, of the Nishihara type wear test piece 1b sampled from the inner part of the rail head 3 is located at a depth of from 24 mm to 26 mm (average value 25 mm) from an upper surface of the rail head 3.
  • the test was conducted in dry ambient conditions and the wear was measured after 1.8 ⁇ 10 5 rotations under conditions of a contact pressure of 1.2 GPa, a slip ratio of -10%, and a rotational speed of 750 rpm (tire test piece: 750 rpm). The wear was calculated from the difference in the mass of the test piece measured before and after the test.
  • wear resistance increases with increasing hardness.
  • wear resistance of a rail having a hardness of HB 400 or higher can be improved by 15% compared to an ordinary heat treated rail (HB 370).
  • HB 370 ordinary heat treated rail
  • the hardness exhibits a large amount of variation in the rail length direction, a difference in wear behavior arises for hard portions and soft portions.
  • the wear changes from 0.37 g to 0.3 g and accordingly exhibits variation of 20% or less.
  • the present disclosure enables minimization of hardness variation in a rail length direction and effectively improves rail durability (extends rail life), particularly in the case of a rail that is laid in a high axle load environment such as a heavy freight railway or a mining railway, and thus demonstrates a significant effect in industrial use.
  • Si is added to the rail material as a deoxidizing material and in order to raise the equilibrium transformation temperature (TE) and reinforce the pearlite structure (increase hardness by refining the lamellar structure).
  • TE equilibrium transformation temperature
  • these effects are small when Si content is less than 0.1%.
  • an increase in the Si content promotes decarburization and promotes formation of rail surface defects. Therefore, the upper limit for the Si content is 1.5%.
  • the Si content is preferably in a range of 0.5% to 1.3%.
  • Mn has an effect of lowering the actual pearlite transformation temperature and narrowing pearlite lamellar spacing, and is an effective element for achieving high hardness. However, these effects are small when Mn content is less than 0.01%. On the other hand, addition of greater than 1.5% of Mn to improve hardenability facilitates transformation to bainite or martensite. Therefore, the upper limit for the Mn content is 1.5%.
  • the Mn content is preferably in a range of 0.3% to 1.2%.
  • the upper limit for the P content is 0.035%.
  • a preferable range for the P content has an upper limit of 0.025%.
  • the lower limit for the P content is preferably 0.001%.
  • Cr raises the equilibrium transformation temperature (TE), contributes to refinement of pearlite lamellar spacing, and increases hardness and strength. In order to obtain such effects, it is necessary to add 0.2% or greater of Cr. On the other hand, adding greater than 2.0% of Cr increases occurrence of welding defects while also increasing hardenability and promoting martensite formation. Therefore, the upper limit for Cr content is 2.0%.
  • the Cr content is more preferably in a range of 0.26% to 1.00%.
  • one or more of 1.0% or less of Cu, 0.5% or less of Ni, 0.5% or less of Mo, and 0.15% or less of V may be added.
  • Ni is an effective element for improving toughness and ductility. Ni is also an effective element for inhibiting Cu cracking through combined addition with Cu. Therefore, in a situation in which Cu is added, Ni is preferably also added. However, these effects are not noticeable when Ni content is less than 0.01%. Therefore, in a situation in which Ni is added, the lower limit for the Ni content is preferably 0.01% or greater. On the other hand, adding greater than 0.5% of Ni increases hardenability and promotes formation of martensite. Therefore, the upper limit for the Ni content is preferably 0.5%. The Ni content is more preferably in a range of 0.05% to 0.50%.
  • Mo is an effective element for increasing strength, but this effect is small when Mo content is less than 0.01%. Therefore, the lower limit for the Mo content is preferably 0.01%. On the other hand, adding greater than 0.5% of Mo causes formation of martensite as a result of increased hardenability and dramatically decreases toughness and ductility. Therefore, the upper limit for the Mo content is preferably 0.5%.
  • the Mo content is more preferably in a range of 0.05% to 0.30%.
  • V 0.15% or less
  • V forms VC, VN, or the like as a fine precipitate in ferrite and is an element that contributes to achieving high hardness through precipitation strengthening of ferrite.
  • the solvation temperature of VC or VN is sufficiently lower than that of Ti or Nb such as to have little influence on recrystallization behavior of austenite during rolling and therefore has little influence on variation of properties in the rail length direction.
  • V also acts as a hydrogen trapping site and can be expected to exhibit an effect of inhibiting delayed fracture. Therefore, 0.001% or greater of V is preferably added.
  • the upper limit for V content is preferably 0.15%.
  • the V content is more preferably in a range of 0.005% to 0.12%.
  • the balance excluding the aforementioned components is Fe and incidental impurities.
  • N and 0.003% of O may be allowed as incidental impurities.
  • Al is effective as a deoxidizing material, Al forms cluster-shaped AlN, which significantly decreases rolling fatigue characteristics. Therefore, Al content is preferably 0.003% or less. Nb and Ti are also contained as incidental impurities as described below.
  • the steel raw material that is used is preferably continuous-cast steel obtained through continuous casting of molten steel that has been adjusted to the chemical composition described above through steelmaking processes such as a process in a blast furnace, molten iron pretreatment, a process in a converter, and RH degassing.
  • the steel raw material is hot rolled to form a rail shape by ordinary caliber rolling or universal rolling.
  • ordinary caliber rolling or universal rolling The following explains the reasons for limitations placed on conditions during the heating and rolling described above and also conditions during subsequent cooling.
  • Heating of the produced steel raw material is required to 1200°C or higher. This is performed with the main objective of sufficiently reducing deformation resistance so as to enable use of a lighter rolling load and also with the objective of homogenization.
  • the heating temperature is required to be 1200°C or higher.
  • the heating temperature is 1300°C or lower from a viewpoint of suppressing scale loss and decarburization.
  • the difference in the time interval between passes for a leading end and a trailing end of a rolled material is fundamentally small. Therefore, inhomogeneity of the austenite structure arising from the above-described difference in the time interval between passes can be resolved. It is therefore necessary for the aforementioned difference in the time interval between passes to be 15 s or less. In other words, a difference in the time interval between passes of 15 s or less can suppress hardness variation in the rail length direction.
  • the difference in the time interval between passes is preferably 12 s or less.
  • the above stipulations are conditions to be applied to rolling performed at 1000°C or lower in the hot rolling.
  • Reverse rolling may be used for rolling performed in a temperature region exceeding 1000°C, a representative example of which is rough rolling. In other words, so long as rolling at 1000°C or lower is performed continuously in a single direction, a preceding stage of rolling in a temperature region exceeding 1000°C may be performed freely.
  • two to seven passes of rolling are performed at 1000°C or lower. The reason for this is that single pass rolling requires a large rolling load and makes shaping difficult, whereas more than seven passes tends to cause a fairly inhomogeneous austenite state and increase hardness variation.
  • the cumulative area reduction rate of rolling performed at 1000°C or lower is required to be 40% or greater. The reason for this is that it is necessary to perform 40% or greater of area reduction processing at 1000°C or lower in order to promote recrystallization refinement of austenite. If the area reduction rate for rolling at 1000°C or lower is less than 40%, recrystallization refinement of austenite is insufficient and coarse austenite may partially remain, which results in increased hardness variation in the rail length direction (rolling direction).
  • a finisher delivery temperature of 900°C or higher is preferable.
  • the finisher delivery temperature is preferably 900°C or higher in order to prevent a decrease in hardness such as described above.
  • Cooling is performed consecutively after the hot rolling under the following conditions.
  • the cooling rate is in a range of 1°C/s to 10°C/s.
  • a cooling rate of greater than 10°C/s does not allow sufficient time for pearlite transformation, causes formation of bainite and martensite, and thus reduces toughness, ductility, and fatigue resistance.
  • a cooling rate of less than 1°C/s does not allow sufficient hardness to be obtained.
  • the cooling rate is preferably in a range of 2°C/s to 8°C/s.
  • the cooling rate exhibits variation of +1°C/s or less in the rolling longitudinal direction. Restricting cooling rate variation to ⁇ 1°C/s or less reduces variation in pearlite lamellar spacing, enables hardness variation of ⁇ HB 10 or less to be achieved, and reduces wear resistance variation and fatigue resistance variation in the rail longitudinal direction.
  • a pearlitic steel rail that has a surface hardness of preferably HB 400 or greater and that exhibits surface hardness variation of ⁇ HB 15 points or less in the rail length direction.
  • a homogeneous and high-hardness pearlitic steel rail that exhibits little hardness variation in the rolling length direction can be obtained.
  • the cooling start temperature and the cooling stop temperature are results for surface temperature of a rail corner measured by a thermoviewer.
  • the rail cooling rate is an average value of cooling rates measured from cooling start and end temperatures and cooling times measured at 5 m intervals in the length direction. With regards to cooling rate variation in the length direction, it was determined whether the difference between a largest value and a smallest value in variation of the cooling rates was greater than ⁇ 1°C/s or was less than or equal to ⁇ 1°C/s.
  • the hardness of rails according to the present disclosure exhibited extremely small variation of ⁇ HB 15 or less in the rail length direction, whereas the hardness of rails that deviated from the scope of the present disclosure in terms of either or both of chemical composition and rolling conditions exhibited variation of greater than ⁇ HB 15.

Description

    TECHNICAL FIELD
  • The present disclosure relates to a rail, particularly a rail having high hardness and small hardness variation, and also to a method for manufacturing the rail.
  • BACKGROUND
  • Freight cars used on freight transportation and mining railways tend to have heavier loading weights than passenger cars, which results in heavy loads acting on the axles of the freight cars and a severe contact environment between the freight car wheels and rails. Rails used under these conditions are expected to exhibit wear resistance and are conventionally made from steel having a pearlite structure.
  • In recent years, there has been a trend toward even heavier loading weights of freight, minerals, and so forth in order to improve railway transport efficiency, which has led a further increase in rail wear and a decrease in rail service life. Accordingly, there is demand for improved rail wear resistance in order to extend rail service life and numerous high hardness rails have been proposed in which rail hardness is enhanced.
  • For example, PTL 1, PTL 2, PTL 3, and PTL 4 each disclose a hypereutectoid rail having increased cementite content and a manufacturing method thereof. Moreover, PTL 5, PTL 6, and PTL 7 each disclose a technique for increasing hardness by refining the lamellar spacing of a pearlite structure in steel containing the eutectoid level of carbon content.
  • With regards to a method for manufacturing a rail, PTL 8 proposes a method for manufacturing a high hardness rail having superior head internal fatigue resistance. In rolling of a rail steel slab in this method, finish rolling is performed at a head surface temperature of 850°C to 1050°C to leave final finishing, and after a time interval between passes of at least 3 seconds and no greater than 1 minute, one pass or a plurality of passes of final finish rolling are performed at a head surface temperature of 800°C to 950°C and with a rolling reduction of 10% or less per pass. Thereafter, accelerated cooling is started at a cooling rate of 2°C/s to 4°C/s for 0.1 seconds to 10 seconds to cool the temperature at less than 5 mm from the surface of the head and corner of the rail to the Ar1 transformation temperature or lower, and cooling is continued at a maximum surface cooling rate of at least 4°C/s and no greater than 30°C/s.
  • PTL 9 describes a method for manufacturing a high toughness rail that exhibits a pearlite metal structure. In this method, after rough rolling of a steel slab of low-alloy steel or carbon steel containing 0.60% to 1.00% of C into a rail shape, continuous finish rolling is performed for three or more rolling passes at a rail surface temperature of 850°C to 1000°C with a cross-section area reduction rolling reduction of 5% to 30% per pass and 10 seconds or less between rolling passes, and thereafter the rail is allowed to cool or is cooled from 700°C or higher to a temperature in a range of 500°C to 700°C at a rate of 2°C/s to 15°C/s.
  • Furthermore, PTL 10 discloses a method for manufacturing a pearlitic rail having superior wear resistance and ductility in which at least rough rolling and finish rolling are performed on a steel slab for rail rolling that contains, in mass%, 0.65% to 1.20% of C, 0.05% to 2.00% of Si, and 0.05% to 2.00% of Mn, the balance being Fe and incidental impurities. In the finish rolling, rolling is performed at a rail head surface temperature of no higher than 900°C and no lower than the Ar3 transformation point or the Arcm transformation point, a head cumulative area reduction rate of 20% or greater, and with a reaction force ratio of 1.25 or greater, which is a value obtained by dividing a reaction force value of the roller by a reaction force value for the same cumulative area reduction rate and a rolling temperature of 950°C. After the finish rolling, the rail head surface is cooled to 550°C or lower at a cooling rate of 2°C/s to 30°C/s by accelerated cooling or natural cooling. Further, PTL 11 discloses a method of manufacturing a rail with a surface hardness of at most 370 HV, including a cooling step for providing uniform hardness over the whole length of the rail. PTL 12 discloses a method for manufacturing a pearlite based rail having excellent wear resistance and ductility.
  • Rails used in high axle load railways, the main examples of which being railways for freight transportation and mining, are expected to have superior wear resistance in order to improve rail durability and, in response, there have been various proposals for rails, such as described above, that focus on increasing hardness.
  • CITATION LIST Patent Literature
    • PTL 1: JP 4272385 B
    • PTL 2: JP 3078461 B
    • PTL 3: JP 3081116 B
    • PTL 4: JP 3513427 B
    • PTL 5: JP 4390004 B
    • PTL 6: JP 2009-108396 A
    • PTL 7: JP 2009-235515 A
    • PTL 8: JP 3423811 B
    • PTL 9: JP 3113137 B
    • PTL 10: JP 2008-50687 A
    • PTL 11: JP 2773867 B2
    • PTL 12: US 2004/0187981 A1
    SUMMARY (Technical Problem)
  • A rail is manufactured by hot rolling a steel raw material to a length of as long as 100 m or greater and, hardness of the rail exhibits variation in the rail length direction that is dependent on the method of manufacture. Consequently, the rail may experience uneven wear when laid and thus may be unable to sufficiently demonstrate its effects. Although it is extremely important, therefore, to reduce hardness variation in the longitudinal direction of rolling, PTL 1-10 make no mention of this hardness variation.
  • In consideration of the above, an objective of the present disclosure is to provide a rail that exhibits excellent wear resistance and reduced hardness variation in the rail length direction, and also a method for manufacturing the rail.
  • (Solution to Problem)
  • The inventors sampled test pieces from steel materials having pearlite structures corresponding to rails of differing hardness and conducted a rail wear test with respect to the test pieces in order to investigate a relationship between hardness and wear. The results of the investigation are shown in FIG. 1.
  • The wear test was a comparative test in which actual contact conditions between a pearlite steel rail and a wheel were simulated using a Nishihara type wear test apparatus that enables wear resistance evaluation in a short period of time. The test was conducted as illustrated in FIG. 2 by rotating a Nishihara type wear test piece 1 of 30 mm in outer diameter, sampled from a rail head, in contact with a tire test piece 2. The arrows in FIG. 2 indicate the rotation directions of the Nishihara type wear test piece 1 and the tire test piece 2, respectively. The tire test piece was obtained by sampling a round bar of 32 mm in diameter from a normal rail head stipulated by JIS E1101, subjecting the round bar to heat treatment such as to have a tempered martensite structure and a Brinell hardness (Brinell load 29.4 kN) of HB 370, and subsequently processing the round bar into the shape illustrated in FIG. 2. Nishihara type wear test pieces 1 were sampled from two locations in a rail head 3 as illustrated in FIG. 3. A test piece sampled from a surface layer of the rail head 3 is denoted Nishihara type wear test piece 1a and a test piece sampled from an inner part of the rail head 3 is denoted Nishihara type wear test piece 1b. The center, in a longitudinal direction, of the Nishihara type wear test piece 1b sampled from the inner part of the rail head 3 is located at a depth of from 24 mm to 26 mm (average value 25 mm) from an upper surface of the rail head 3. The test was conducted in dry ambient conditions and the wear was measured after 1.8 ×105 rotations under conditions of a contact pressure of 1.2 GPa, a slip ratio of -10%, and a rotational speed of 750 rpm (tire test piece: 750 rpm). The wear was calculated from the difference in the mass of the test piece measured before and after the test.
  • As illustrated in FIG. 1, wear resistance increases with increasing hardness. For example, wear resistance of a rail having a hardness of HB 400 or higher can be improved by 15% compared to an ordinary heat treated rail (HB 370). However, if the hardness exhibits a large amount of variation in the rail length direction, a difference in wear behavior arises for hard portions and soft portions. For example, in a situation in which the hardness is HB 415 points and exhibits variation of ±15 or less (i.e., the hardness varies within a range from at least HB 400 to no greater than HB 430), the wear changes from 0.37 g to 0.3 g and accordingly exhibits variation of 20% or less. On the other hand, in a situation in which the hardness is HB 415 points and exhibits variation of ±30 (i.e., the hardness varies in a range from at least HB 385 to no greater than HB 445), the wear changes from 0.40 g to 0.27 g and accordingly exhibits variation of 33%. In consideration of the above, reducing hardness variation in the longitudinal direction of a rail in accompaniment to increasing rail hardness enables uniform rail wear and contributes to improving rail life. It is preferable for wear to be as uniform as possible in the length direction because wear proceeds due to contact between the rail and wheels during use. Taking into account the results of the test described above, hardness variation in the rail length direction is preferably of a level such that wear variation is 20% or less. The inventors discovered that surface hardness variation of ±HB 15 or less ensures superior wear resistance along the length direction and contributes to improved rail life. This discovery led to the present disclosure.
  • Specifically, the present invention relates to a rail according to claim 1 and a rail manufacturing method according to claim 2
  • (Advantageous Effect)
  • The present disclosure enables minimization of hardness variation in a rail length direction and effectively improves rail durability (extends rail life), particularly in the case of a rail that is laid in a high axle load environment such as a heavy freight railway or a mining railway, and thus demonstrates a significant effect in industrial use.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • In the accompanying drawings:
    • FIG. 1 is a graph illustrating a relationship between the rail material hardness and wear;
    • FIG. 2 illustrates a Nishihara type wear test piece of which wear resistance is evaluated, wherein (a) is a plan view and (b) is a side view; and
    • FIG. 3 is a cross-sectional view of a rail head illustrating sampling positions of Nishihara type wear test pieces.
    DETAILED DESCRIPTION
  • Firstly, the reasons for limitations on each component in the chemical composition of a rail will be explained. When components are expressed in "%", this refers to "mass%" unless otherwise specified.
  • C: 0.60% to 1.0%
  • C is an important element in a pearlitic rail for forming cementite, increasing hardness and strength, and improving wear resistance. However, these effects are small when C content is less than 0.60% and therefore the lower limit for the C content is 0.60%. On the other hand, although an increase in the C content, and thus an increase in cementite content, is expected to lead to higher hardness and strength, an increase in the C content also decreases ductility. Furthermore, an increase in the C content broadens the γ + θ temperature range and promotes softening of a heat-affected zone. Taking into account these influences, the upper limit for the C content is 1.0%. The C content is preferably in a range of 0.73% to 0.85%.
  • Si: 0.1% to 1.5%
  • Si is added to the rail material as a deoxidizing material and in order to raise the equilibrium transformation temperature (TE) and reinforce the pearlite structure (increase hardness by refining the lamellar structure). However, these effects are small when Si content is less than 0.1%. On the other hand, an increase in the Si content promotes decarburization and promotes formation of rail surface defects. Therefore, the upper limit for the Si content is 1.5%. The Si content is preferably in a range of 0.5% to 1.3%.
  • Mn: 0.01% to 1.5%
  • Mn has an effect of lowering the actual pearlite transformation temperature and narrowing pearlite lamellar spacing, and is an effective element for achieving high hardness. However, these effects are small when Mn content is less than 0.01%. On the other hand, addition of greater than 1.5% of Mn to improve hardenability facilitates transformation to bainite or martensite. Therefore, the upper limit for the Mn content is 1.5%. The Mn content is preferably in a range of 0.3% to 1.2%.
  • P: 0.035% or less
  • P content of greater than 0.035% decreases toughness and ductility. Therefore, the upper limit for the P content is 0.035%. A preferable range for the P content has an upper limit of 0.025%. On the other hand, taking into consideration the increased cost of steelmaking when special refining or the like is performed, the lower limit for the P content is preferably 0.001%.
  • S: 0.030% or less
  • S forms coarse MnS extending in the rolling direction and decreases ductility and toughness. Therefore, the upper limit for S content is 0.030%. On the other hand, restricting the S content to less than 0.0005% requires a significant increase in steel making cost due to, for example, a large increase in steelmaking process time. Therefore, the lower limit for the S content is preferably 0.0005%. The S content is preferably 0.001% to 0.015%.
  • Cr: 0.1% to 2.0%
  • Cr raises the equilibrium transformation temperature (TE), contributes to refinement of pearlite lamellar spacing, and increases hardness and strength. In order to obtain such effects, it is necessary to add 0.2% or greater of Cr. On the other hand, adding greater than 2.0% of Cr increases occurrence of welding defects while also increasing hardenability and promoting martensite formation. Therefore, the upper limit for Cr content is 2.0%. The Cr content is more preferably in a range of 0.26% to 1.00%.
  • Besides the chemical components described above, one or more of 1.0% or less of Cu, 0.5% or less of Ni, 0.5% or less of Mo, and 0.15% or less of V may be added.
  • Cu: 1.0% or less
  • Cu is an element that can provide even higher hardness through solid solution strengthening. Cu also has an effect of suppressing decarburization. In order to obtain these effects, 0.01% or greater of Cu is preferably added. On the other hand, adding greater than 1.0% of Cu makes surface cracking more likely to occur during continuous casting or rolling. Therefore, the upper limit for Cu content is preferably 1.0%. Moreover, the Cu content is more preferably in a range of 0.05% to 0.6%.
  • Ni: 0.5% or less
  • Ni is an effective element for improving toughness and ductility. Ni is also an effective element for inhibiting Cu cracking through combined addition with Cu. Therefore, in a situation in which Cu is added, Ni is preferably also added. However, these effects are not noticeable when Ni content is less than 0.01%. Therefore, in a situation in which Ni is added, the lower limit for the Ni content is preferably 0.01% or greater. On the other hand, adding greater than 0.5% of Ni increases hardenability and promotes formation of martensite. Therefore, the upper limit for the Ni content is preferably 0.5%. The Ni content is more preferably in a range of 0.05% to 0.50%.
  • Mo: 0.5% or less
  • Mo is an effective element for increasing strength, but this effect is small when Mo content is less than 0.01%. Therefore, the lower limit for the Mo content is preferably 0.01%. On the other hand, adding greater than 0.5% of Mo causes formation of martensite as a result of increased hardenability and dramatically decreases toughness and ductility. Therefore, the upper limit for the Mo content is preferably 0.5%. The Mo content is more preferably in a range of 0.05% to 0.30%.
  • V: 0.15% or less
  • V forms VC, VN, or the like as a fine precipitate in ferrite and is an element that contributes to achieving high hardness through precipitation strengthening of ferrite. The solvation temperature of VC or VN is sufficiently lower than that of Ti or Nb such as to have little influence on recrystallization behavior of austenite during rolling and therefore has little influence on variation of properties in the rail length direction. Moreover, V also acts as a hydrogen trapping site and can be expected to exhibit an effect of inhibiting delayed fracture. Therefore, 0.001% or greater of V is preferably added. On the other hand, when greater than 0.15% of V is added, the above-described effects reach saturation and the alloying cost increases dramatically. Therefore, the upper limit for V content is preferably 0.15%. The V content is more preferably in a range of 0.005% to 0.12%.
  • The balance excluding the aforementioned components is Fe and incidental impurities.
  • For example, up to 0.006% of N and 0.003% of O may be allowed as incidental impurities. Furthermore, although Al is effective as a deoxidizing material, Al forms cluster-shaped AlN, which significantly decreases rolling fatigue characteristics. Therefore, Al content is preferably 0.003% or less. Nb and Ti are also contained as incidental impurities as described below.
  • Nb: 0.003% or less Ti: 0.003% or less
  • Nb and Ti are effective elements for improving hardness and wear resistance due to forming carbides or carbonitrides that strengthen the matrix. However, Nb and Ti are harmful elements that promote hardness variation of the rail in the longitudinal direction and are therefore not generally added, although incidentally mixed in Nb and Ti of 0.003% or less is allowable. Specifically, addition of Nb or Ti causes hardness to change to a greater extent in accordance with material heating, rolling, or cooling conditions and thus causes changes in hardness in the rolling length direction to be more sensitively associated with variation in these conditions. In metallurgical terms, inhomogeneity of heated austenite particles is promoted and, at the same time, inhibition of recrystallization of austenite during rolling and a change in pearlite transformation temperature associated therewith are greatly increased compared to steel in which Nb and Ti are not added, and this may promote hardness variation.
  • In addition to the chemical composition described above, it is essential that surface hardness exhibits variation of ±HB 15 points or less in the rail length direction. The reason for this is that the change in rail wear reaches 20% or greater if the hardness variation is greater than ±HB 15 points. Furthermore, it is more preferable that the surface hardness exhibits variation of ±HB 10 points or less in the rail length direction because hardness variation of ±HB 10 points or less enables restriction of the change in rail wear to less than 15%.
  • The following provides a specific description of rail manufacture conditions.
  • First, the steel raw material that is used is preferably continuous-cast steel obtained through continuous casting of molten steel that has been adjusted to the chemical composition described above through steelmaking processes such as a process in a blast furnace, molten iron pretreatment, a process in a converter, and RH degassing.
  • The steel raw material is hot rolled to form a rail shape by ordinary caliber rolling or universal rolling. The following explains the reasons for limitations placed on conditions during the heating and rolling described above and also conditions during subsequent cooling.
  • [Heating temperature prior to hot rolling: 1200°C to 1300°C]
  • Heating of the produced steel raw material is required to 1200°C or higher. This is performed with the main objective of sufficiently reducing deformation resistance so as to enable use of a lighter rolling load and also with the objective of homogenization. In order to sufficiently obtain these effects, the heating temperature is required to be 1200°C or higher. The heating temperature is 1300°C or lower from a viewpoint of suppressing scale loss and decarburization.
  • [Rolling in a rail length direction in a temperature region not exceeding 1000°C is performed over a plurality of passes with a time interval between passes exhibiting variation of 15 s or less in the rail length direction]
  • The steel raw material heated as described above is shaped into a rail shape by hot rolling. In the hot rolling, it is important that a plurality of rolling passes at temperatures not exceeding 1000°C are performed by rolling repeatedly in a single direction in order to minimize variation in a time interval between passes. Note that the time interval between passes refers to the interval between a time when a given portion in the longitudinal direction (rolling direction) of a rolled rail material is bitten by a roller and a time when the given portion is next bitten by the roller. The time interval between passes differs the most for the top (leading end) of the rolled rail material and the bottom (trailing end) of the rolled rail material.
  • In conventional reverse rolling, during an interval between a rolled top portion (leading end) being bitten by the roller in a given pass and starting to be bitten in a next pass, the next pass is performed in order by first feeding a rolled bottom portion (trailing end) to the roller, which lengthens the time interval between passes for the rolled top portion. On the other hand, after the rolled bottom portion (trailing end) has passed through in a given pass, the bottom portion is bitten first by the roller in the next pass, which shortens the time interval between passes. The difference in the time interval between passes for the leading end and the trailing end described above, which is a characteristic of reverse rolling, influences the state of the austenite structure and also influences hardness variation after transformation to pearlite. In contrast, when continuous rolling is performed in a single direction, the difference in the time interval between passes for a leading end and a trailing end of a rolled material is fundamentally small. Therefore, inhomogeneity of the austenite structure arising from the above-described difference in the time interval between passes can be resolved. It is therefore necessary for the aforementioned difference in the time interval between passes to be 15 s or less. In other words, a difference in the time interval between passes of 15 s or less can suppress hardness variation in the rail length direction. The difference in the time interval between passes is preferably 12 s or less.
  • The above stipulations are conditions to be applied to rolling performed at 1000°C or lower in the hot rolling. Reverse rolling may be used for rolling performed in a temperature region exceeding 1000°C, a representative example of which is rough rolling. In other words, so long as rolling at 1000°C or lower is performed continuously in a single direction, a preceding stage of rolling in a temperature region exceeding 1000°C may be performed freely. In the hot rolling, two to seven passes of rolling are performed at 1000°C or lower. The reason for this is that single pass rolling requires a large rolling load and makes shaping difficult, whereas more than seven passes tends to cause a fairly inhomogeneous austenite state and increase hardness variation.
  • [Cumulative area reduction rate of 40% or greater for a portion forming a rail head]
  • The cumulative area reduction rate of rolling performed at 1000°C or lower is required to be 40% or greater. The reason for this is that it is necessary to perform 40% or greater of area reduction processing at 1000°C or lower in order to promote recrystallization refinement of austenite. If the area reduction rate for rolling at 1000°C or lower is less than 40%, recrystallization refinement of austenite is insufficient and coarse austenite may partially remain, which results in increased hardness variation in the rail length direction (rolling direction).
  • [Finisher delivery temperature of 900°C or higher]
  • When performing continuous rolling in a single direction in order to reduce variation in the time interval between passes along the whole length of the rolled material, a finisher delivery temperature of 900°C or higher is preferable. The reason for this it that if the finisher delivery temperature is lower than 900°C, overall hardness decreases and variation thereof increases due to reasons such as a decrease in the cooling start temperature of on-line heat treatment performed consecutively after rolling and promotion of transformation to pearlite (transformation at higher temperature). Therefore, the finisher delivery temperature is preferably 900°C or higher in order to prevent a decrease in hardness such as described above.
  • Cooling is performed consecutively after the hot rolling under the following conditions.
  • [Cooling of the rail head from a cooling start temperature of 800°C or higher to a cooling stop temperature of 400°C to 600°C at a cooling rate of 1°C/s to 10°C/s]
  • Firstly, the cooling start temperature is preferably 800°C or higher. Specifically, a cooling start temperature of lower than 800°C may not enable sufficient supercooling or allow sufficient surface hardness to be obtained. The cooling stop temperature is required to be 600°C or lower. Sufficient hardness cannot be obtained if the cooling stop temperature is greater than 600°C. Saturation is reached in terms of hardness once cooling is performed to 400°C or lower and productivity is adversely affected by increased cooling time. Therefore, cooling is stopped at 400°C or higher.
  • The cooling rate is in a range of 1°C/s to 10°C/s. A cooling rate of greater than 10°C/s does not allow sufficient time for pearlite transformation, causes formation of bainite and martensite, and thus reduces toughness, ductility, and fatigue resistance. On the other hand, a cooling rate of less than 1°C/s does not allow sufficient hardness to be obtained. The cooling rate is preferably in a range of 2°C/s to 8°C/s.
  • Moreover, the cooling rate exhibits variation of +1°C/s or less in the rolling longitudinal direction. Restricting cooling rate
    variation to ±1°C/s or less reduces variation in pearlite lamellar spacing, enables hardness variation of ±HB 10 or less to be achieved, and reduces wear resistance variation and fatigue resistance variation in the rail longitudinal direction.
  • The cooling performed consecutively after the hot rolling is preferably performed by air blast cooling or mist cooling. Air blast cooling is accelerated cooling in which air is forcefully blown against the rail head. Mist cooling involves mixing air and water and blowing a water mist against the rail head.
  • In order to control and minimize cooling rate variation in the rolling longitudinal direction, in the case of air blast cooling, for example, it is necessary to control air pressure at intervals of 5 m or less (preferably 3 m or less), adjust air pressure on-line in accordance with temperature variation of the rail in the longitudinal direction measured before the cooling, and perform control such that the cooling rate is constant in the length direction. In the case of mist cooling, cooling is preferably performed by controlling the amount of water and pressure in the longitudinal direction in the same way as described above.
  • Through the above-described chemical composition and performance of the above-described rolling and cooling, a pearlitic steel rail can be obtained that has a surface hardness of preferably HB 400 or greater and that exhibits surface hardness variation of ±HB 15 points or less in the rail length direction. In other words, a homogeneous and high-hardness pearlitic steel rail that exhibits little hardness variation in the rolling length direction can be obtained.
  • EXAMPLES
  • Steels having the chemical compositions shown in Table 1 were made and cast steels obtained through continuous casting thereof were subjected to heating, hot rolling, and cooling to manufacture a 136-pound rail or a 141-pound rail for each steel. The manufacture conditions are shown together with investigation results for surface hardness and variation thereof in Table 2.
    Figure imgb0001
  • Herein, the variation in the time interval between passes in the rolling conditions indicates the difference between the time elapsing from a leading end of a rolled material being rolled to the leading end being next rolled and the time elapsing from a trailing end of the rolled material being rolled to the trailing end being next rolled. As explained further above, when rolling is performed by conventional reverse rolling, the time interval between passes is extended for a rolled top portion and shortened for a rolled bottom portion. Thus, the difference in the time interval between passes for the leading end (top portion) and the trailing end (bottom portion) of the rolled material is particularly evident in reverse rolling. In contrast, the difference in the time interval between passes associated with a leading end and a trailing end of a rolled material is smaller in continuous rolling in a single direction and therefore inhomogeneity of a produced structure can be resolved as shown in Table 2.
  • Note that the cooling start temperature and the cooling stop temperature are results for surface temperature of a rail corner measured by a thermoviewer. The rail cooling rate is an average value of cooling rates measured from cooling start and end temperatures and cooling times measured at 5 m intervals in the length direction. With regards to cooling rate variation in the length direction, it was determined whether the difference between a largest value and a smallest value in variation of the cooling rates was greater than ±1°C/s or was less than or equal to ±1°C/s.
  • Furthermore, the rail head surface hardness and microstructure of each of the manufactured rails was evaluated. The rail head surface hardness was evaluated by removing 0.5 mm or greater of a decarburized layer using a grinder and measuring the Brinell hardness of points at 5 m intervals in the rail length direction. In the same way, microscope samples were cut out and the microstructures thereof were observed.
  • The evaluation results are shown in Table 2.
    Figure imgb0002
    Figure imgb0003
  • The hardness of rails according to the present disclosure exhibited extremely small variation of ±HB 15 or less in the rail length direction, whereas the hardness of rails that deviated from the scope of the present disclosure in terms of either or both of chemical composition and rolling conditions exhibited variation of greater than ±HB 15.

Claims (2)

  1. A rail comprising
    a chemical composition consisting of, in mass%:
    0.60% to 1.0% of C;
    0.1% to 1.5% of Si;
    0.01% to 1.5% of Mn;
    0.035% or less of P;
    0.030% or less of S;
    0.1% to 2.0% of Cr,
    and optionally one or more of
    0.006% or less of N;
    0.003% or less of O;
    0.003% or less of Al;
    0.003% or less of Nb;
    0.003% or less of Ti;
    1.0% or less of Cu;
    0.5% or less of Ni;
    0.5% or less of Mo; and
    0.15% or less of V,
    the balance being Fe and incidental impurities, wherein
    the surface hardness of the head of the rail is HB 400 or greater and the surface hardness of a head of the rail exhibits variation of ±HB 10 points or less in a length direction of the rail.
  2. A rail manufacturing method consisting of:
    heating to a temperature of between 1200°C and 1300°C, a steel raw material having a chemical composition consisting of, in mass%:
    0.60% to 1.0% of C,
    0.1% to 1.5% of Si,
    0.01% to 1.5% of Mn,
    0.035% or less of P,
    0.030% or less of S,
    0.1% to 2.0% of Cr,
    and optionally one or more of
    0.006% or less of N;
    0.003% or less of O;
    0.003% or less of Al;
    0.003% or less of Nb;
    0.003% or less of Ti;
    1.0% or less of Cu;
    0.5% or less of Ni;
    0.5% or less of Mo; and
    0.15% or less of V,
    the balance being Fe and incidental impurities;
    hot rolling the steel raw material after the heating, the hot rolling being performed continuously in a single direction such that rolling in a rail length direction in a temperature region not exceeding 1000°C is performed over 2 to 7 passes with a difference in the time interval between passes of 15 s or less in the rail length direction, a cumulative area reduction rate of 40% or greater for a portion forming a rail head, and a finisher delivery temperature of 900°C or higher; and
    cooling the rail head after the hot rolling from a cooling start temperature of 800°C or higher to a cooling stop temperature of 400°C to 600°C at a cooling rate of 1°C/s to 10°C/s, wherein the cooling rate in the cooling exhibits variation of ± 1°C/s or less in the rail direction.
EP15768893.8A 2014-03-24 2015-03-24 Rail and method for manufacturing same Active EP3124636B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2014060786 2014-03-24
PCT/JP2015/001659 WO2015146150A1 (en) 2014-03-24 2015-03-24 Rail and method for manufacturing same

Publications (4)

Publication Number Publication Date
EP3124636A4 EP3124636A4 (en) 2017-02-01
EP3124636A1 EP3124636A1 (en) 2017-02-01
EP3124636B1 true EP3124636B1 (en) 2019-03-06
EP3124636B2 EP3124636B2 (en) 2023-05-17

Family

ID=54194697

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15768893.8A Active EP3124636B2 (en) 2014-03-24 2015-03-24 Rail and method for manufacturing same

Country Status (8)

Country Link
US (1) US20170101692A1 (en)
EP (1) EP3124636B2 (en)
JP (1) JP6150008B2 (en)
CN (1) CN106103772B (en)
AU (1) AU2015237464B2 (en)
BR (1) BR112016022007B1 (en)
CA (1) CA2936780C (en)
WO (1) WO2015146150A1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015146150A1 (en) 2014-03-24 2015-10-01 Jfeスチール株式会社 Rail and method for manufacturing same
JP6288261B2 (en) * 2014-05-29 2018-03-07 新日鐵住金株式会社 Rail and manufacturing method thereof
CN106636891A (en) * 2016-11-17 2017-05-10 马鞍山市银鼎机械制造有限公司 Preparation method of ball milling cast iron for shock resisting railway steel rail
CN107326302B (en) * 2017-05-26 2018-10-19 北京交通大学 A kind of anti-corrosion bainitic steel, rail and preparation method
WO2019102258A1 (en) * 2017-11-27 2019-05-31 Arcelormittal Method for manufacturing a rail and corresponding rail
US11492689B2 (en) 2018-03-30 2022-11-08 Jfe Steel Corporation Rail and method for manufacturing same
US11566307B2 (en) 2018-03-30 2023-01-31 Jfe Steel Corporation Rail
EP3778966A1 (en) * 2018-03-30 2021-02-17 JFE Steel Corporation Rail and method for manufacturing same
SE543919C2 (en) * 2019-05-17 2021-09-21 Husqvarna Ab Steel for a sawing device
CN112575137B (en) * 2020-10-26 2022-03-25 邯郸钢铁集团有限责任公司 Method for direct tapping during high-speed rail steel converter smelting
JP2023551416A (en) * 2020-11-17 2023-12-08 アルセロールミタル Steel for rails and method for manufacturing the rails
CN114058824B (en) * 2021-11-26 2023-12-08 武汉钢铁有限公司 Production method for improving hardness uniformity of heat-treated steel rail tread and steel rail obtained by production method

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6289818A (en) 1985-10-14 1987-04-24 Nippon Kokan Kk <Nkk> Heat treatment of rail
US4886558A (en) 1987-05-28 1989-12-12 Nkk Corporation Method for heat-treating steel rail head
JPH07216454A (en) 1994-01-31 1995-08-15 Nippon Steel Corp Heat treatment of rail
EP0685566A1 (en) 1993-12-20 1995-12-06 Nippon Steel Corporation Rail of high abrasion resistance and high tenacity having pearlite metallographic structure and method of manufacturing the same
JP2773867B2 (en) 1987-10-19 1998-07-09 新日本製鐵株式会社 Hot rail cooling
JP2001234238A (en) 2000-02-18 2001-08-28 Nippon Steel Corp Producing method for highly wear resistant and high toughness rail
US20030192625A1 (en) 2002-04-10 2003-10-16 Cordova J. Vincent High impact and wear resistant steel
CN1754973A (en) 2004-09-27 2006-04-05 铁道科学研究院 Heat treating rail iron containing Cr
JP2010077481A (en) 2008-09-25 2010-04-08 Jfe Steel Corp High internal hardness type pearlitic steel rail excellent in wear resistance and fatigue deterioration resistance, and method for manufacturing the same
US20100116381A1 (en) 2007-03-28 2010-05-13 Jfe Steel Corporation Internal high hardness type pearlitic rail with excellent wear resistance and rolling contact fatigue resistance and method for producing same
JP2014060786A (en) 2010-07-15 2014-04-03 Kyocera Corp Radio communication system, mobile station, base station and radio communication method
EP3124636A1 (en) 2014-03-24 2017-02-01 JFE Steel Corporation Rail and method for manufacturing same

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2773867A (en) * 1954-05-17 1956-12-11 Glidden Co Process for dehalogenating steroids
JPH01104721A (en) * 1987-10-19 1989-04-21 Nippon Steel Corp Method for cooling high-temperature rail
US6804795B1 (en) * 1999-04-02 2004-10-12 Sony Corporation Electronic device and its repairing method
EP1493831A4 (en) * 2002-04-05 2006-12-06 Nippon Steel Corp Pealite based rail excellent in wear resistance and ductility and method for production thereof
JP5145795B2 (en) * 2006-07-24 2013-02-20 新日鐵住金株式会社 Method for producing pearlitic rails with excellent wear resistance and ductility
US20110155821A1 (en) * 2008-10-31 2011-06-30 Masaharu Ueda Pearlite rail having superior abrasion resistance and excellent toughness
JP5238930B2 (en) * 2009-02-12 2013-07-17 Jfeスチール株式会社 Abrasion resistant rail and method of manufacturing the same
WO2010095354A1 (en) * 2009-02-18 2010-08-26 新日本製鐵株式会社 Pearlitic rail with excellent wear resistance and toughness
CN102220545B (en) * 2010-04-16 2013-02-27 攀钢集团有限公司 High-carbon and high-strength heat-treated steel rail with high wear resistance and plasticity and manufacturing method thereof

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6289818A (en) 1985-10-14 1987-04-24 Nippon Kokan Kk <Nkk> Heat treatment of rail
US4886558A (en) 1987-05-28 1989-12-12 Nkk Corporation Method for heat-treating steel rail head
JP2773867B2 (en) 1987-10-19 1998-07-09 新日本製鐵株式会社 Hot rail cooling
EP0685566A1 (en) 1993-12-20 1995-12-06 Nippon Steel Corporation Rail of high abrasion resistance and high tenacity having pearlite metallographic structure and method of manufacturing the same
JPH07216454A (en) 1994-01-31 1995-08-15 Nippon Steel Corp Heat treatment of rail
JP2001234238A (en) 2000-02-18 2001-08-28 Nippon Steel Corp Producing method for highly wear resistant and high toughness rail
US20030192625A1 (en) 2002-04-10 2003-10-16 Cordova J. Vincent High impact and wear resistant steel
CN1754973A (en) 2004-09-27 2006-04-05 铁道科学研究院 Heat treating rail iron containing Cr
US20100116381A1 (en) 2007-03-28 2010-05-13 Jfe Steel Corporation Internal high hardness type pearlitic rail with excellent wear resistance and rolling contact fatigue resistance and method for producing same
JP2010077481A (en) 2008-09-25 2010-04-08 Jfe Steel Corp High internal hardness type pearlitic steel rail excellent in wear resistance and fatigue deterioration resistance, and method for manufacturing the same
JP2014060786A (en) 2010-07-15 2014-04-03 Kyocera Corp Radio communication system, mobile station, base station and radio communication method
EP3124636A1 (en) 2014-03-24 2017-02-01 JFE Steel Corporation Rail and method for manufacturing same

Also Published As

Publication number Publication date
US20170101692A1 (en) 2017-04-13
EP3124636A4 (en) 2017-02-01
WO2015146150A1 (en) 2015-10-01
JPWO2015146150A1 (en) 2017-04-13
AU2015237464A1 (en) 2016-08-11
JP6150008B2 (en) 2017-06-21
CN106103772B (en) 2018-05-22
CN106103772A (en) 2016-11-09
CA2936780A1 (en) 2015-10-01
AU2015237464B2 (en) 2018-02-01
EP3124636B2 (en) 2023-05-17
EP3124636A1 (en) 2017-02-01
CA2936780C (en) 2018-10-02
BR112016022007B1 (en) 2021-05-11

Similar Documents

Publication Publication Date Title
EP3124636B1 (en) Rail and method for manufacturing same
US20190338402A1 (en) Method for manufacturing railway vehicle wheel
JP5292875B2 (en) Internal high-hardness pearlitic steel rail with excellent wear resistance, fatigue damage resistance and delayed fracture resistance, and manufacturing method thereof
US9534278B2 (en) Rail
JP5282506B2 (en) Internal high hardness type pearlitic steel rail with excellent wear resistance and fatigue damage resistance and method for manufacturing the same
EP3249070B1 (en) Rail
EP3717142B1 (en) Method for manufacturing a rail and corresponding rail
JP5267306B2 (en) High carbon steel rail manufacturing method
CA3094798C (en) Rail and method for manufacturing same
JP4964489B2 (en) Method for producing pearlitic rails with excellent wear resistance and ductility
JP5326343B2 (en) Manufacturing method of high internal hardness rail
JP6064515B2 (en) rail
JP2020070495A (en) Rail and production method thereof
JP2002363698A (en) Rail having excellent rolling fatigue damage resistance and wear resistance, and production method therefor
JP6137043B2 (en) Rail manufacturing method
CN111868285B (en) Rail and method for manufacturing same
JP2001040453A (en) High strength pearlitic rail excellent in toughness and its production

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

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

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

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20160805

A4 Supplementary search report drawn up and despatched

Effective date: 20161221

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20180405

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

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

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: C22C 38/06 20060101ALI20180814BHEP

Ipc: C21D 6/00 20060101ALI20180814BHEP

Ipc: C22C 38/48 20060101ALI20180814BHEP

Ipc: C22C 38/02 20060101ALI20180814BHEP

Ipc: C22C 38/50 20060101ALI20180814BHEP

Ipc: C22C 38/24 20060101ALI20180814BHEP

Ipc: C22C 38/38 20060101ALI20180814BHEP

Ipc: C22C 38/22 20060101ALI20180814BHEP

Ipc: C22C 38/46 20060101ALI20180814BHEP

Ipc: C22C 38/42 20060101ALI20180814BHEP

Ipc: C22C 38/04 20060101ALI20180814BHEP

Ipc: C21D 8/00 20060101ALI20180814BHEP

Ipc: C22C 38/00 20060101AFI20180814BHEP

Ipc: C22C 38/18 20060101ALI20180814BHEP

Ipc: C21D 9/04 20060101ALI20180814BHEP

Ipc: C22C 38/26 20060101ALI20180814BHEP

Ipc: C22C 38/28 20060101ALI20180814BHEP

Ipc: C22C 38/34 20060101ALI20180814BHEP

INTG Intention to grant announced

Effective date: 20180914

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

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

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: AT

Ref legal event code: REF

Ref document number: 1104641

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190315

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602015025934

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20190306

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190606

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190607

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190606

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602015025934

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190706

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190324

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20190331

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190706

26 Opposition filed

Opponent name: VOESTALPINE SCHIENEN GMBH

Effective date: 20191206

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190331

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20191001

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190324

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190331

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20190606

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190331

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190606

PLBB Reply of patent proprietor to notice(s) of opposition received

Free format text: ORIGINAL CODE: EPIDOSNOBS3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20190324

REG Reference to a national code

Ref country code: AT

Ref legal event code: UEP

Ref document number: 1104641

Country of ref document: AT

Kind code of ref document: T

Effective date: 20190306

PLAY Examination report in opposition despatched + time limit

Free format text: ORIGINAL CODE: EPIDOSNORE2

PLBC Reply to examination report in opposition received

Free format text: ORIGINAL CODE: EPIDOSNORE3

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20150324

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20190306

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

APBM Appeal reference recorded

Free format text: ORIGINAL CODE: EPIDOSNREFNO

APBP Date of receipt of notice of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA2O

APBU Appeal procedure closed

Free format text: ORIGINAL CODE: EPIDOSNNOA9O

PUAH Patent maintained in amended form

Free format text: ORIGINAL CODE: 0009272

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

Free format text: STATUS: PATENT MAINTAINED AS AMENDED

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20230208

Year of fee payment: 9

Ref country code: AT

Payment date: 20230227

Year of fee payment: 9

27A Patent maintained in amended form

Effective date: 20230517

AK Designated contracting states

Kind code of ref document: B2

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230512