EP1304393A1 - Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres - Google Patents

Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres Download PDF

Info

Publication number
EP1304393A1
EP1304393A1 EP01949987A EP01949987A EP1304393A1 EP 1304393 A1 EP1304393 A1 EP 1304393A1 EP 01949987 A EP01949987 A EP 01949987A EP 01949987 A EP01949987 A EP 01949987A EP 1304393 A1 EP1304393 A1 EP 1304393A1
Authority
EP
European Patent Office
Prior art keywords
piston ring
nitriding
less
resistance
stainless steel
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.)
Granted
Application number
EP01949987A
Other languages
German (de)
English (en)
Other versions
EP1304393B1 (fr
EP1304393A4 (fr
Inventor
Junya KKRiken Kashiwazaki Plant TAKAHASHI
Toru Kabushiki Kaisha Kashiwazaki Plant ONUKI
Shigeo Kabushiki Kaisha Kashiwazaki Plant INOUE
Mitsutaka Sasakura
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.)
Riken Corp
Tokusen Kogyo Co Ltd
Original Assignee
Riken Corp
Tokusen Kogyo Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Riken Corp, Tokusen Kogyo Co Ltd filed Critical Riken Corp
Publication of EP1304393A1 publication Critical patent/EP1304393A1/fr
Publication of EP1304393A4 publication Critical patent/EP1304393A4/fr
Application granted granted Critical
Publication of EP1304393B1 publication Critical patent/EP1304393B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • 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
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires 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
    • C21D9/40—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rings; for bearing races
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • 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
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding
    • C23C8/26—Nitriding of ferrous surfaces
    • 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
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a piston ring used in an internal combustion engine, particularly, a piston ring consisting of high chromium martensitic stainless steel with nitriding, having improved scuffing resistance (seizure resistance), cracking resistance (failure resistance) and fatigue resistance.
  • the present invention is also related to a production method of the piston ring.
  • the piston rings are thinned to reduce weight and to follow the high rotation of the engine.
  • Material properties of the piston rings such as wear resistance, scuffing resistance and fatigue resistance, and the like must be improved to enable thinning of a piston ring.
  • the conventional cast-iron piston rings have, therefore, been replaced with steel piston rings particularly from a view point of the fatigue resistance and heat resistance.
  • the scuffing resistance of the steel piston-ring is inferior to that of the cast-iron piston-ring, any surface-treatment is usually applied to the sliding surface of steel piston ring.
  • Steels for piston ring are roughly classified into carbon steel, silicon-chromium steel, and martensitic stainless steel.
  • the chromium plating is applied to carbon steels and silicon chromium steels.
  • Gas nitriding is applied to martensitic stainless steels.
  • the chromium plating was the most frequent surface treatment of the steel piston ring previously, but has been mostly replaced at present with the nitriding, because the scuffing resistance of the chromium plating under high load is poor, and, further, the waste-liquid of the plating must be treated so as not to incur any environmental problem.
  • High chromium martensitic stainless steel mainly used at present for the piston ring with nitriding is JIS SUS440B equivalent composition of C: 0.80-0.95%; Cr: 17.0-18.0%; Si: 0.25-0.50%; Mn: 0.25-0.40%; Mo: 0.70-1.25%; V: 0.07-0.15%; and Fe in balance.
  • the nitrides in the nitriding layer are mainly compounds of Cr, V and Mo, which may contain the solute Fe.
  • Chromium which is the main component of this steel, is dissolved in the iron matrix, and is also present in the form of Cr carbides.
  • the affinity of Cr for nitrogen is higher than that for carbon, when nitrogen diffuses from the surface by the nitriding, the reaction between the nitrogen and Cr carbides occurs to form the Cr nitrides.
  • the Cr content of SUS 440B equivalent material is as high as 17.0-18.0%, hard Cr nitrides are dispersed in the nitriding layer in an appropriate area %. The nitriding layer is, therefore, relatively hard and improves the wear resistance and scuffing resistance.
  • martensitic stainless steel with nitriding having improved scuffing resistance, which contains Si: 0.25% or less, Mn: 0.30% or less; one or more of Mo, W, V and Nb: 0.3-2.5% or Cu: 4.0% or less; Ni: 2.0% or less, and Al: 1.5% or less.
  • Japanese Unexamined Patent Publication 11(1999)-106874 discloses that when the quantity of M 7 C 3 carbide in the microstructure is suppressed to 4.0% or less in area %, not only scuffing resistance but also workability of the piston ring steel material are improved.
  • liners are forced into the cylinder block of Diesel engines. These engines are changed to a monolithic block cast-iron of narrow bore distance without liners so as to attain weight reduction and cost saving.
  • the combustion pressure tends to be increased from the viewpoints of waste gas purification and power increase.
  • graphite dispersion is not uniform and soft ferrite phase as the cause of scuffing is unevenly distributed.
  • the formation of TiN, CrN and the like is carried out by means of ion plating.
  • the ion plating can improve the wear resistance and the scuffing resistance but the production cost is high.
  • the reputation of ion plating by the users at present is not favorable in the light of the cost performance.
  • an object of the present invention to provide a high chromium martensitic stainless steel piston ring with nitriding and its production method, which ring is cost-effective and, which incurs neither wear, scuffing, cracking nor fatigue fracture even when used in a Diesel engine operated at high revolution and high combustion pressure, particularly, a cast-iron monolithic block Diesel engine, which is expected to be increasingly used in the future because of weight reduction.
  • the microstructure of the nitriding layer generally shows mainly hard nitrides dispersed in the tempered martensite matrix.
  • the mechanism of scuffing is strongly dependent upon the microscopic unevenness on the sliding surface.
  • hard particles disperse in the relatively soft matrix.
  • the microscopic unevenness is, therefore, defined by the size and dispersion state of the hard particles.
  • the hard convex particles can attain the effects as described above, provided that they are from sub microns to a few microns in size and dispersed in an amount of 5% by area or more. In the case in which the hard particles are extremely small and case in which they are small in quantity, the mechanism according to action and effect of the convex hard particles mentioned above cannot be expected.
  • the sliding surface of even such cast iron is modified by appropriate sliding referred to by experts as break-in or compatibility. That is, the following phenomenon occurs.
  • break-in or compatibility When the rough inner surface of a cylinder is smoothened during the sliding, the ferrite is removed and the covered graphite is exposed.
  • an oil film on the sliding surface is frequently liable to be absent.
  • friction force applied on the outer peripheral surface of a piston ring is increased.
  • the large friction force is repeatedly applied on the outer peripheral surface of a piston ring.
  • the nitriding layer is, therefore, repeatedly subjected to large stress resulting in initiation and enlargement of cracks in a direction perpendicular to the sliding direction.
  • the stress applied is lessened, while the cracks propagate with the lapse of time.
  • the nitriding layer may locally peel in the surface, and the inner surface of a cylinder may be damaged.
  • the scuffing is, therefore, liable to occur in the initial period of sliding. Since the grain boundary compounds in the nitriding layer are very brittle, the presence of them promotes the initiation and propagation of cracks.
  • a large number of hard particles, mainly Cr nitrides, in proper size in the nitriding layer should be uniformly dispersed in matrix in order to decrease the probability of contacts between matrix and cylinder and to prevent the initial stage scuffing.
  • the grain boundary compounds formed during nitiriding should be fine to suppress the initiation of cracks in connection with those compounds. In this fine microstructure, even if cracks initiate, the development of those can be suppressed.
  • the eutectic Cr carbide ( ⁇ phase: (Cr, Fe) 7 C 3 ) crystallizes in the grain boundaries of primary austenite ( ⁇ phase). Cr carbides exceeding 20 ⁇ min the largest diameter are present in the high chromium martensitic stainless steel, which is solidified as above and then hot rolled, spheroidizing annealed, and finally quenched and tempered.
  • ⁇ phase (Cr, Fe) 7 C 3
  • Cr carbides exceeding 20 ⁇ min the largest diameter are present in the high chromium martensitic stainless steel, which is solidified as above and then hot rolled, spheroidizing annealed, and finally quenched and tempered.
  • Tetsu and Hagane Journal of Japan Institute of Iron and Steel
  • Netsushori Vol. 36, No. 4, p. 234-238 (1996) reports the mechanical properties of 16.5% Cr - 0.65% C martensitic stainless steel with the addition of 0.25% of N. That is, the quenching temperature, at which the highest hardness is obtained, shifts to lower temperature with the increase in N content. The elongation also increases with the increase in N content. It is explained that the solution amount of N in the austenite phase increases and the austenite phase is stabilized with the increase in quenching temperature.
  • Japanese Unexamined Patent Publication Nos. 9-289053 and 9-287058 disclose the rolling bearing, in which the refining of Cr carbides due to the N addition is utilized.
  • the present inventors have studied the scuffing mechanisms mentioned above and the influence of relatively large lamellar grain boundary compounds on cracking in sliding surface of piston ring and applied the refining technology of Cr carbide using N addition. As a result, it is found to be desirable that a large number of nitrides dispersed uniformly in the nitriding layer and especially grain boundary compounds are fine in size.
  • This fine microstructure provides a high chromium martensitic stainless steel piston ring with nitriding having improved scuffing, cracking and fatigue resistances even when it is used in internal combustion engines operated under high revolution and high power conditions, particularly, recent weight reduced cast iron mono-block Diesel engine, etc.
  • the high-chromium martensitic stainless steel piston ring with nitriding is characterized in that it comprises the high-chromium martensitic stainless steel, which consists, by weight %, of C: 0.3 to 1.0%; Cr: 14.0 to 21.0%, N: 0.05 to 0.50%, at least one of Mo, V, Wand Nb: 0.03 to 3.0% in total, Si: 0.1 to 1.0%, Mn 0.1 to 1.0%, P: 0.05% or less, S: 0.05% or less, the balance being Fe and unavoidable impurities; and, the high chromium martensitic stainless steel has a nitriding sliding layer, which comprises hard particles consisting of carbide, nitride and carbo-nitride, mainly nitride, and the hard particles in the surface of the nitriding layer are in a range of from 0.5 to 2.0 ⁇ m of average diameter, 7 ⁇ m or less of the largest diameter, and from 5 to 30%
  • the grain boundary compounds observed in the longitudinal cross section of the nitriding layer are 20 ⁇ m or less in size (length).
  • the nitriding surface layer having the microstructural feature mentioned above has hardness in the range of from Hv 900 to 1400 and has sufficient depth from the surface.
  • the method for producing the high chromium martensitic stainless steel piston ring with nitriding comprises: melting the steel having the above composition followed by adding nitrogen; casting the molten steel into an ingot; hot rolling; annealing; cold wire drawing; cold rolling to form an approximate cross sectional shape of the piston ring; quenching; tempering to provide the wire materials; bending the wire material into the form of the piston ring; strain-relief annealing; rough grinding of the side surfaces; nitriding; removal of surface compound layer; grinding butt ends; finish grinding of side surfaces; and lapping of the outer peripheral surfaces.
  • the nitriding may be gas nitriding, ion nitriding and radical nitriding. The nitriding is carried out at in a range of 450 to 600°C for 1 to 20 hours.
  • C is an interstitial solute element in Fe and increases hardness of matrix.
  • C is easily combined with Cr, Mo, V, W and Nb and forms carbides.
  • the carbides are converted mainly to nitrides during the nitriding. In other words, the nitrides enhance the wear resistance and the scuffing resistance of the sliding surface of a piston ring.
  • the C content is less than 0.3%, the hardening and formation of carbides are not sufficient.
  • coarse eutectic Cr carbide ⁇ phase: M 7 C 3 carbide
  • the carbon content is, therefore, in a range of from 0.3 to 1.0%, preferably in a range of from 0.4 to 0.9%.
  • Cr is a substitutional solute element in Fe. Cr not only improves the corrosion resistance but also induces the solution strengthening and hence improvement in the thermal setting resistance.
  • the thermal setting is a phenomenon that sealing property is deteriorated by tension decrease due to creep during operation of a piston ring at high temperature.
  • Cr reacts with C in steel and forms Cr carbides. These Cr carbides easily react with N, which intrudes from the surface during nitriding, and are converted to Cr nitrides.
  • the Cr nitrides are dispersed in the nitriding layer as the hard particles. The hard particles in the nitriding layer exceedingly enhance the wear resistance and the scuffing resistance of the sliding surface of a piston ring.
  • the Cr content is less than 14%, the formation of Cr carbides is not sufficient.
  • the Cr content is more than 21%, the ⁇ ferrite is formed and toughness is hence lowered.
  • the Cr concentration in the matrix becomes so high that the Ms (the starting temperature of martensitic transformation) is so lowered such that satisfactory quenching hardness is not obtained.
  • the Cr content is, therefore, in a range of from 14 to 21%, preferably in a range of from 16 to 19%.
  • N is an interstitial element in Fe, as C is.
  • Ternary Fe - Cr - C phase diagram can be expressed by a pseudo-binary phase diagram by cutting at, for example, the 17% Cr line.
  • An eutectic reaction occurs between Fe and C, the concentration of which is given by the left end of the eutectic line.
  • molten steel remains around the grain boundaries of primary crystals. When the temperature further falls, the molten steel undergoes the eutectic reaction.
  • the nitrogen is added in accordance with the present invention, the C concentration at the left side mentioned above is higher than that of the molten steel without nitrogen. Therefore, the eutectic reaction and hence the formation of ⁇ carbide are suppressed.
  • the super saturated C and N precipitate around the primary ⁇ grains in the form of lamellar M 23 C 6 and M 2 N precipitates.
  • the N content is less than 0.05%, the ⁇ phase crystallizes.
  • the N content is more than 0.50%, the amount of M 2 N precipitates in the form of a rod increases, so that the toughness is lowered.
  • the N content is, therefore, in a range of from 0.05 to 0.50%, more preferably in a range of from 0.10 to 0.30%.
  • the solute N in the matrix impedes the diffusion of C and also contributes to refining of the grain boundary compounds.
  • Nitrogen up to 0.2% can be added under normal pressure. Nitrogen content of more than 0.2% necessitates melting under pressure N 2 atmosphere. The nitrogen content in a range of from 0.05 to 0.20% is, therefore, preferable from the viewpoint of N addition.
  • Any one of Mo, V, W and Nb is a carbide former and enhances wear and scuffing resistances.
  • Mo prevents softening during the tempering and nitriding treatments and plays an important role in attaining the dimension stability of a piston ring.
  • V promotes nitriding, and, therefore, the hardness of a nitriding layer containing V is high. Any one of these elements is effective for enhancing the properties of a piston ring.
  • the total content of at least one of Mo, V, W and Nb is less than 0.03%, their effects are virtually negligible.
  • the total content of these element(s) is more than 3%, the workability is seriously impaired and the toughness is lowered.
  • the total content of at least one of Mo, V, Wand Nb is, therefore, from 0.03 to 3.0%.
  • Si is a deoxidizing additive. Si is also dissolved in Fe and enhances the softening resistance in tempering. The so-called thermal setting resistance can, therefore, be improved. When the Si content is less than 0.1%, its effect is slight. On the other hand, when the Si content is more than 1.0%, the toughness is impaired. The Si content is, therefore, in a range of from 0.1 to 1.0%.
  • Mn is also a deoxidizing additive.
  • the Mn content is less than 0.1%, its effect is slight.
  • the Mn content is more than 1.0%, the workability is impaired.
  • the Mn content is, therefore, from 0.1 to 1.0%.
  • P forms inclusions with Mn and the like and lowers the fatigue strength and corrosion resistance.
  • P is an impurity of steel. The less P, the better.
  • the P content is, therefore, 0.05% or less from a practical point of view.
  • P is 0.03% or less.
  • S lowers the fatigue strength and corrosion resistance, as P does.
  • S is an impurity of steel. The less S, the better.
  • the S content is, therefore, 0.05% or less from a practical point of view.
  • S is 0.03 % or less.
  • the steel consisting of the composition ranges as described above is subjected to formation of a microstructure having improved scuffing resistance, that is, a number of fine nitride particles are present in the nitriding layer.
  • the hard particles consisting of nitrides, i.e., mainly Cr nitride, carbides and carbonitrides, present in the surface of the nitriding layer should have an average diameter in a range of from 0.2 to 2 ⁇ m, the largest diameter of 7 ⁇ m or less, and area % in a range of from 5 to 30%.
  • the average particle diameter is less than 0.2 ⁇ m, the convexities of the hard particles are not effective for preventing scuffing.
  • the average particle diameter is more than 2 ⁇ m
  • scuffing is liable to occur when the load is high.
  • the largest diameter is more than 7 ⁇ m
  • the microstructure of the nitriding layer becomes non-uniform so that scuffing is liable to occur under high load.
  • the area % is less than 5%
  • scuffing is liable to occur.
  • the area % of nitrides is more than 30%, the wire drawing and the bending into the piston ring form after melting become difficult.
  • a preferable area % is from 10 to 25%.
  • the microstructure of the nitriding layer having improved cracking resistance is such that the grain boundary compounds observed in the longitudinal cross section of a piston ring are 20 ⁇ m or less in size (length). When the longest length is more than 20 ⁇ m, there arises a problem that the cracking is liable to occur under high load.
  • the microstructure of the nitriding layer as described above according to the present invention is attributable to the microstructure of stainless steel.
  • no coarse eutectic Cr carbide ( ⁇ phase: (Cr, Fe) 7 C 3 carbide) is present in the steel which has been successively hot rolled, spheroidizing heat treated, cold wire drawn, quenched and tempered. This is attained by the nitrogen addition.
  • a preferable quenching temperature is, therefore, in a range of from 850 to 1000°C, from the viewpoints as described above.
  • the quenching temperature is less than 850°C, no hardening occurs and the desired hardness is not attained because of precipitation of the ⁇ phase.
  • the quenching temperature is more than 1000°C, the carbides coalesce in the holding step at the quenching temperature and the ⁇ crystal grains coarsen. As a result, the coarse carbides are converted to the coarse nitrides.
  • high hardness of from Hv 900 to 1400 is obtained up to a satisfactory depth from the surface by the nitriding treatment for a relatively short period of time.
  • This feature is attributable to the relatively fine ⁇ crystal grains formed at low quenching temperature and thus to the increase of the grain boundaries which are the main diffusion passages of N during the nitriding treatment.
  • the nitriding treatment is carried out in the temperature range of from 450 to 600°C.
  • the treatment temperature of approximately 590°C, at which the nitrogen solubility in the ⁇ -Fe lattice is the greatest, has been considered to be advisable.
  • the treatment temperature is not limited to approximately 590°C.
  • the lower-temperature treatment is more advisable from the viewpoint of dimension stability of a piston ring.
  • the nitriding is carried out at 450 to 600°C for 1 to 20 hours.
  • Figure 1 is a photograph of back scattered electron image of surface of sliding nitriding layer observed by a scanning electron microscope.
  • Figures 1 (a) and (b) correspond to Example 1 and Comparative Example 1, respectively.
  • Figure 2 is an optical microscope photograph of the cross section of a nitriding layer.
  • Figures 2 (a) and (b) correspond to Example 1 and Comparative Example 1, respectively.
  • Figure 3 shows a specimen of the scuffing test.
  • Figure 4 shows the movement mechanism of a friction and wear tester.
  • Figure 5 shows the movement mechanism of a fatigue tester of a piston ring.
  • Figure 6 is a graph showing the fatigue limit.
  • Figure 7 is a photograph showing a crack formed on the sliding surface of Comparative Example 13.
  • the high chromium martensitic stainless steels having a composition shown in Table 1 were melted in an amount of 10kg in a vacuum induction melting furnace. However, less than 0.2% of N was added to the steel during melting under the normal pressure, while 0.2% or more of N was added to steel during melting under pressure N 2 gas atmosphere. Wire material having 12 mm of diameter was obtained by hot working. After acid cleaning, spheroidizing annealing was carried out at 750°C for 10 hours. A wire having a rectangular cross section of 3.5 mm ⁇ 5.0mm was produced through working steps. The wire was passed through a quenching furnace (Ar protective atmosphere) and a tempering furnace (Ar protective atmosphere).
  • the air quenching was carried out from 930°C after keeping approximately 10 minutes at that temperature.
  • the tempering was carried out at 620°C for approximately 25 minutes.
  • the wires were cut into 50 mm long samples for the nitriding treatment.
  • the gas nitriding was carried out at 570°C for 4 hours.
  • the quenching temperature of Comparative Example 1 (H1) was 1100°C as in the conventional method.
  • the other conditions are the same as for the Examples and the other Comparative Examples.
  • the wire samples mentioned above were further cut into lengths of 10 mm for observation of the microscopic structure.
  • the specimens were embedded in resin and were mirror-finished.
  • the observation and quantitative evaluation of the microstructure were carried out using an image analyzer.
  • the back scattered electron image of the sliding nitriding surface was observed by a scanning electron microscope with regard to Example 1 (J1) and Comparative Example (H1).
  • the observed images for Example 1 (J1) and Comparative Example 1 (H1) are shown in Figs. 1 (a) and (b), respectively.
  • the cross section of the nitriding layer was observed by an optical microscope and the observed photographs are shown in Figs. 2(a) and (b), respectively, with regard to Example 1 (J1) and Comparative Example 1 (H1).
  • the hard particles appear black in the back scattered electron image photograph and white in the optical microscope photograph. It is apparent that: the hard particles according to the present invention are extremely small in size; and, the grain boundary compounds observed in the cross section of the nitriding layer are extremely small in size.
  • the microstructures of Example 1 through 11 (J1 - J11) and Comparative Examples 1 - 8 (H1 - H18) were quantitatively evaluated with regard to the average particle diameter, the largest particle diameter and area ratio of the hard particles in the sliding nitriding surface and the longest length of the grain boundary compounds in the cross section of the nitriding layer. These results are shown in Table 2 together with the hardness of the sliding surface of nitriding layer.
  • a scuffing test sample in the form of Japanese katakana " ⁇ " having 45 mm of the total length is shown.
  • the wire material was shaped into scuffing test samples of two-pin integral type.
  • the opposite material was made of FC250 and was in the form of a disc of 60 mm in diameter and 12 mm in thickness.
  • the sliding surface of disc 2 (Fig. 4) was adjusted to the surface roughness (Rz) of from 1 to 2 ⁇ m.
  • the scuffing test was carried out using a friction and wear tester (Product of Riken, Trade name "Triborik I").
  • the front ends of the pin (reference numeral 1, Fig. 4) are convex sliding surfaces having 20 mm of radius. The front ends were subjected to gas nitriding treatment. The 5 to 20 ⁇ m thick compound layers (white layer) formed on the front ends were removed by grinding. The front ends were then mirror-finished by polishing.
  • the surface roughness (Rz) of the sliding surface of FC250 disc (Fig.4, Reference numeral 2) used is adjusted to 1-2 ⁇ m
  • the movement mechanism of the friction wear tester is illustrated in Fig. 4.
  • the testing conditions of scuffing were as follows.
  • the scuffing surface pressure was calculated from the scuffing load, and the wear area of the sliding surface.
  • the scuffing surface pressure obtained is shown with regard to Example 1 - 11 (J1 - 11) and Comparative Examples 1 - 8 (H1 - H8) Scuffing Surface Pressure (MPa) J1 454 J2 443 J3 469 J4 428 J5 458 J6 420 J7 464 J8 430 J9 441 J10 419 J11 452 H1 376 H2 - H3 340 H4 - H5 328 H6 297 H7 388 H8 -
  • Example 1 The materials having the chemical composition of Example 1 were worked into a wire and air quenched from the temperature shown in Table 4.
  • the gas nitriding treatment was carried out by the same method as in Example 1.
  • the microstructure of the nitriding layer was quantitatively analyzed. The results are shown in Table 4.
  • Example 1 and Comparative Example 1 were subjected to working steps to form a compression ring having a rectangular cross section.
  • the nominal diameter (d 1 ) was 95.0 mm
  • thickness (a 1 ) was 3.35 mm
  • width (h 1 ) was 2.3 mm.
  • the quenching was carried out by means of passing through the quenching furnace at 930°C for 10 minutes and then air-cooling.
  • the tempering was carried out by means of the tempering furnace at 620°C for approximately 25 minutes.
  • the continuous quenching and tempering was carried out.
  • the gas nitriding was carried out at 570°C for 4 hours.
  • the quenching temperature of Comparative Example 12 was 1100°C as in the conventional method.
  • the other conditions are the same as for the Comparative Example 15.
  • the produced compression piston ring was tested in a fatigue tester, the movement mechanism of which is illustrated in Fig. 5.
  • the butt ends of the compression piston ring were cut at both ends to widen the dimension of free gap.
  • the so-treated piston ring 3 was set by an adjuster 9 in the tester in such a manner that its diameter was reduced to the nominal diameter.
  • the eccentric cam 4 was then rotated so as to impart repeated strokes at 40 cycles per second for further reducing the diameter to less than the nominal one, until the piston ring 3 fractured. The number of stress applied at the fracture was obtained.
  • This test was repeated, while changing the applied stress to the sample of identical specification.
  • the so-called S-N diagram and finally fatigue limit diagram shown in Fig. 6 were obtained.
  • Example 15 is outstandingly improved over Comparative Example 12.
  • Example 1 Example 16, 17
  • Example 7 Examples 18, 19
  • Comparative Example 1 Comparative Examples 13, 14
  • compression ring had a rectangular cross section. Its nominal diameter (d 1 ) was 99.2 mm, thickness (a 1 ) was 3.8 mm, and the width (h 1 ) was 2.5 mm.
  • the body of the oil ring had a saddle-shape cross section. Its nominal diameter (d 1 ) was 99.2 mm, thickness (a 1 ) was 2.5 mm, and the width (h 1 ) was 3.0 mm.
  • the produced compression rings and oil rings were mounted in a four-cylinder Diesel engine of 3200 cc displacement. These rings were mounted on a piston and combined with a monolithic cast-iron block and operated for 100 hours for the endurance test under the following condition.
  • the piston ring which is made of high chromium martensitic stainless steel with nitriding.
  • the laminar grain boundary compounds are refined, too.
  • Such microstructure can be formed by the addition of nitrogen and the low temperature quenching.
  • the wear resistance, scuffing resistance, cracking resistance and fatigue resistance are improved as a result of the microstructure.
  • the piston ring according to the present invention can, therefore, he advantageously used in internal combustion engines operated under high rotation and high power conditions, particularly, the recent light-weight monolithic block Diesel engine.
  • the piston ring according to the present invention can also be advantageously used for the piston ring of a small motor truck, in which the ring fatigue problem is likely to occur when using the exhaust brake.
  • the piston ring according to the present invention can be appropriately embodied as the body of a two-piece oil ring and the rail of a three-piece oil ring.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
EP01949987A 2000-07-17 2001-07-16 Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres Expired - Lifetime EP1304393B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2000216255 2000-07-17
JP2000216255A JP4724275B2 (ja) 2000-07-17 2000-07-17 耐スカッフィング性、耐クラッキング性及び耐疲労性に優れたピストンリング及びその製造方法
PCT/JP2001/006127 WO2002006546A1 (fr) 2000-07-17 2001-07-16 Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres

Publications (3)

Publication Number Publication Date
EP1304393A1 true EP1304393A1 (fr) 2003-04-23
EP1304393A4 EP1304393A4 (fr) 2005-08-03
EP1304393B1 EP1304393B1 (fr) 2006-08-09

Family

ID=18711547

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01949987A Expired - Lifetime EP1304393B1 (fr) 2000-07-17 2001-07-16 Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres

Country Status (10)

Country Link
US (2) US20040040631A1 (fr)
EP (1) EP1304393B1 (fr)
JP (1) JP4724275B2 (fr)
KR (1) KR100507424B1 (fr)
CN (1) CN1210427C (fr)
AR (1) AR029730A1 (fr)
BR (1) BR0112573B1 (fr)
DE (1) DE60122164T2 (fr)
TW (1) TW521093B (fr)
WO (1) WO2002006546A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008019716A1 (fr) * 2006-08-17 2008-02-21 Federal-Mogul Burscheid Gmbh Matériau acier, utilisé notamment pour produire des segments de pistons
EP2159295A3 (fr) * 2008-09-01 2011-04-20 MINEBEA Co., Ltd. Acier inoxydable martensitique et palier à roulement l'utilisant
WO2014206575A1 (fr) * 2013-06-27 2014-12-31 Liebherr-Aerospace Lindenberg Gmbh Pièce de structure d'un aéronef
WO2015124169A1 (fr) * 2014-02-18 2015-08-27 Schmiedewerke Gröditz Gmbh Acier au chrome pour pièces de machines fortement sollicitées à l'usure, en particulier pour matrices à pelleter
WO2016062620A1 (fr) * 2014-10-20 2016-04-28 Mahle Metal Leve S/A Segment de piston et moteur à combustion interne
WO2017021330A1 (fr) * 2015-08-03 2017-02-09 Mahle International Gmbh Segments de piston en acier coulé nitrurable et procédé de production

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI258547B (en) * 2002-08-27 2006-07-21 Riken Co Ltd Side rails for combined oil control ring and their nitriding method
JP4500259B2 (ja) * 2003-03-31 2010-07-14 日立金属株式会社 内燃機関用ピストン及びその製造方法
SE526805C8 (sv) * 2004-03-26 2006-09-12 Sandvik Intellectual Property Stållegering
CN100363524C (zh) * 2005-03-17 2008-01-23 上海材料研究所 一种耐腐蚀磨损的马氏体不锈钢及其制造方法及用途
JP4648094B2 (ja) * 2005-05-31 2011-03-09 株式会社神戸製鋼所 耐疲労割れ性に優れた高Ｃｒ鋳鉄およびその製造方法
KR101038002B1 (ko) 2006-04-20 2011-05-30 히타치 긴조쿠 가부시키가이샤 내연 기관용 피스톤 링재
JP4954644B2 (ja) * 2006-08-31 2012-06-20 日本ピストンリング株式会社 シリンダライナとピストンリングの組み合わせ
DE102008032884B4 (de) * 2008-07-14 2018-09-20 Mahle International Gmbh Ventileinrichtung, Wärmetauscher und Aufladesystem zur Aufladung einer Brennkraftmaschine mit einem Ladefluid
BRPI0905228B1 (pt) * 2009-12-29 2017-01-24 Mahle Metal Leve Sa anel de pistão nitretado resistente à propagação de trincas
JP5676146B2 (ja) * 2010-05-25 2015-02-25 株式会社リケン 圧力リング及びその製造方法
KR101239589B1 (ko) 2010-12-27 2013-03-05 주식회사 포스코 고내식 마르텐사이트 스테인리스강 및 그 제조방법
WO2012166851A1 (fr) 2011-06-02 2012-12-06 Aktiebolaget Skf Procédé de carbonitruration pour article en acier inoxydable martensitique et article en acier inoxydable à résistance à la corrosion améliorée
KR101268736B1 (ko) 2011-06-24 2013-05-29 주식회사 포스코 마르텐사이트계 스테인리스강 및 이의 제조 방법
KR20140097390A (ko) 2011-11-30 2014-08-06 페더럴-모걸 코오포레이숀 피스톤 링 용도를 위한 고 모듈러스 내마모성 회주철
UA111115C2 (uk) 2012-04-02 2016-03-25 Ейкей Стіл Пропертіс, Інк. Рентабельна феритна нержавіюча сталь
CN103866202B (zh) * 2012-12-14 2016-08-17 钟庆辉 采用改性不锈钢材料制作发动机活塞环气环方法
KR102005580B1 (ko) * 2012-12-17 2019-07-30 두산인프라코어 주식회사 플랜지 타입의 슬라이딩 베어링, 이를 구비하는 슬라이딩 베어링 조립체 및 건설기계용 관절 조립체
JP6010508B2 (ja) * 2013-07-03 2016-10-19 ボーグワーナー インコーポレーテッド 摺動部材の製造方法、ならびにチェーン用リンクの製造方法および当該リンクを備えたチェーンの製造方法
US20160208372A1 (en) * 2013-08-27 2016-07-21 University Of Virginia Patent Foundation Lattice materials and structures and related methods thereof
BR102013031497A2 (pt) * 2013-12-06 2015-11-10 Mahle Int Gmbh processo de revestimento de um cilindro de um motor a combustão interna e cilindro/camisa de motor
WO2015114822A1 (fr) * 2014-01-31 2015-08-06 Ｔｐｒ株式会社 Segment de compression et matériau de base pour segment de compression
JP5859048B2 (ja) * 2014-03-20 2016-02-10 サンコール株式会社 ピストンリング及びピストンリング用金属製平角線
CN104018083B (zh) * 2014-06-20 2016-01-06 重庆材料研究院有限公司 含氮不锈轴承钢及制备方法
US10196718B2 (en) * 2015-06-11 2019-02-05 Hitachi Metals, Ltd. Steel strip for cutlery
JP6139605B2 (ja) * 2015-07-17 2017-05-31 株式会社リケン ピストンリング及びその製造方法
BR102015027438B8 (pt) 2015-10-29 2021-12-21 Inst De Pesquisas Tecnologicas Do Estado De Sao Paulo S/A Anéis de pistão em aços-ferramenta fundidos e seu processo de fabricação
CN106053053B (zh) * 2016-08-10 2018-08-03 三峡大学 一种活塞环疲劳试验机及疲劳试验方法
CN106119729A (zh) * 2016-08-18 2016-11-16 娄土岭 一种精密铸造轴承钢
CN106619032A (zh) * 2016-11-25 2017-05-10 天津文康科技有限公司 一种机电一体化医疗护理装置
CN106555129A (zh) * 2016-12-02 2017-04-05 机械科学研究总院青岛分院 一种含氮不锈轴承钢及制备方法
CN107326272A (zh) * 2017-05-27 2017-11-07 苏州铭晟通物资有限公司 一种钢材
JP7404792B2 (ja) 2018-12-04 2023-12-26 株式会社プロテリアル マルテンサイト系ステンレス鋼部品およびその製造方法
KR20210104418A (ko) * 2020-02-17 2021-08-25 현대자동차주식회사 가변 오일 펌프용 아우터링 및 이의 제조방법
DE102020202259A1 (de) 2020-02-21 2021-08-26 Federal-Mogul Burscheid Gmbh Gleitelement, insbesondere Kolbenring, und Verfahren zur Herstellung desselben
CN114962460A (zh) 2021-02-25 2022-08-30 斯凯孚公司 经热处理的滚子轴承圈
CN113528941A (zh) * 2021-06-16 2021-10-22 中国兵器科学研究院宁波分院 一种含氮马氏体不锈轴承钢及其制备方法
CN114196875B (zh) * 2021-09-25 2022-10-28 浙江吉森金属科技有限公司 一种阀片用不锈钢及其热处理方法
CN115109891B (zh) * 2022-07-14 2022-12-20 中北大学 一种高碳高铬含氮马氏体不锈钢及其碳化物细化方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0638658A1 (fr) * 1993-08-11 1995-02-15 SOCIETE INDUSTRIELLE DE METALLURGIE AVANCEE S.I.M.A. Société Anonyme Acier martensitique à l'azote à faible teneur en carbone et son procédé de fabrication
EP0710731A2 (fr) * 1994-11-04 1996-05-08 BÖHLER Edelstahl GmbH Utilisation d'un alliage ferreux contenant de l'azote pour pièces de machine soumises à une friction de surface coulissante
EP0799902A1 (fr) * 1994-10-13 1997-10-08 Hitachi Metals, Ltd. Matériau facilement usinable pour segment de piston

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59162346A (ja) * 1983-02-25 1984-09-13 Hitachi Metals Ltd 圧力リング
JPS61144470A (ja) * 1984-12-19 1986-07-02 Riken Corp ピストンリング
JPH01205063A (ja) * 1988-02-10 1989-08-17 Daido Steel Co Ltd 耐摩耗ステンレス鋼部品
US5154433A (en) * 1991-06-14 1992-10-13 Teikoku Piston Ring Co., Ltd. Piston ring
JP3200745B2 (ja) * 1991-11-27 2001-08-20 金井 宏之 ピストンリング用線材
JPH07278758A (ja) * 1994-04-13 1995-10-24 Nippon Steel Corp エンジンガスケット用ステンレス鋼とその製造方法
JPH08134596A (ja) * 1994-11-02 1996-05-28 Nippon Steel Corp 耐応力腐食割れ特性に優れた高強度ステンレス鋼板
JP3484076B2 (ja) * 1998-02-10 2004-01-06 株式会社リケン 内燃機関用ピストンリング
JP3452354B2 (ja) * 2000-01-20 2003-09-29 日本高周波鋼業株式会社 ピストンリング用マルテンサイト系ステンレス鋼及びピストンリング用異形線

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0638658A1 (fr) * 1993-08-11 1995-02-15 SOCIETE INDUSTRIELLE DE METALLURGIE AVANCEE S.I.M.A. Société Anonyme Acier martensitique à l'azote à faible teneur en carbone et son procédé de fabrication
EP0799902A1 (fr) * 1994-10-13 1997-10-08 Hitachi Metals, Ltd. Matériau facilement usinable pour segment de piston
EP0710731A2 (fr) * 1994-11-04 1996-05-08 BÖHLER Edelstahl GmbH Utilisation d'un alliage ferreux contenant de l'azote pour pièces de machine soumises à une friction de surface coulissante

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO0206546A1 *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008019716A1 (fr) * 2006-08-17 2008-02-21 Federal-Mogul Burscheid Gmbh Matériau acier, utilisé notamment pour produire des segments de pistons
EP2159295A3 (fr) * 2008-09-01 2011-04-20 MINEBEA Co., Ltd. Acier inoxydable martensitique et palier à roulement l'utilisant
US8591673B2 (en) 2008-09-01 2013-11-26 Minebea Co., Ltd. Martensitic stainless steel and antifriction bearing using the same
WO2014206575A1 (fr) * 2013-06-27 2014-12-31 Liebherr-Aerospace Lindenberg Gmbh Pièce de structure d'un aéronef
WO2015124169A1 (fr) * 2014-02-18 2015-08-27 Schmiedewerke Gröditz Gmbh Acier au chrome pour pièces de machines fortement sollicitées à l'usure, en particulier pour matrices à pelleter
WO2016062620A1 (fr) * 2014-10-20 2016-04-28 Mahle Metal Leve S/A Segment de piston et moteur à combustion interne
US10487405B2 (en) 2014-10-20 2019-11-26 Mahle Metal Leve S/A Piston ring and internal combustion engine
WO2017021330A1 (fr) * 2015-08-03 2017-02-09 Mahle International Gmbh Segments de piston en acier coulé nitrurable et procédé de production

Also Published As

Publication number Publication date
TW521093B (en) 2003-02-21
BR0112573A (pt) 2003-07-01
WO2002006546A1 (fr) 2002-01-24
CN1210427C (zh) 2005-07-13
BR0112573B1 (pt) 2009-01-13
AR029730A1 (es) 2003-07-10
DE60122164D1 (de) 2006-09-21
CN1458983A (zh) 2003-11-26
EP1304393B1 (fr) 2006-08-09
US20040040631A1 (en) 2004-03-04
JP2002030394A (ja) 2002-01-31
KR20030025275A (ko) 2003-03-28
US20070187002A1 (en) 2007-08-16
EP1304393A4 (fr) 2005-08-03
DE60122164T2 (de) 2007-10-11
JP4724275B2 (ja) 2011-07-13
KR100507424B1 (ko) 2005-08-10

Similar Documents

Publication Publication Date Title
EP1304393B1 (fr) Segment de piston presentant une resistance elevee a l'erosion, a la fissuration et a la fatigue, procede permettant de produire ce segment et combinaison segment de piston et bloc-cylindres
KR101087562B1 (ko) 내연기관용 피스톤 및 그 제조 방법
EP0295111B1 (fr) Acier présentant une résistance élevée à l'usure
US5972128A (en) Cast iron and piston ring
EP1529852B1 (fr) Materiau pour pieces coulissantes auto-lubrifiantes et materiau en fil pour segment de piston
US6527879B2 (en) Self-lubricating piston ring material for internal combustion engine and piston ring
EP1063454B1 (fr) Matériau autolubrifiant pour segment de moteur à combustion et segment de piston
JP2002317225A (ja) ピストンリング
JP4066307B2 (ja) 自己潤滑性を有する内燃機関用ピストンリング材およびピストンリング
JP2909456B2 (ja) 耐スカッフィング性に優れたピストンリング
JP2007321199A (ja) 耐焼付性に優れたピストンリング用鋼材、ピストンリング用異形線、並びにピストンリング
EP1149929B1 (fr) Elément coulissant avec une résistance à l'usure et une résistance à la fatigue améliorées
JPH0559495A (ja) ピストンリング材
JP2000097339A (ja) ピストンリングの組合せ
JPH1180910A (ja) ピストンリング材における耐スカッフィング性および加工性の改善方法
JPH11106874A (ja) 耐スカッフィング性および加工性に優れたピストンリング材

Legal Events

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

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20030117

AK Designated contracting states

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

RBV Designated contracting states (corrected)

Designated state(s): DE ES FR GB

A4 Supplementary search report drawn up and despatched

Effective date: 20050620

RIC1 Information provided on ipc code assigned before grant

Ipc: 7F 16J 9/26 B

Ipc: 7C 22C 38/26 B

Ipc: 7C 22C 38/24 B

Ipc: 7C 22C 38/34 B

Ipc: 7C 22C 38/00 A

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 60122164

Country of ref document: DE

Date of ref document: 20060921

Kind code of ref document: P

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

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: 20061120

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20070510

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

Ref country code: GB

Payment date: 20070724

Year of fee payment: 7

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

Ref country code: FR

Payment date: 20070724

Year of fee payment: 7

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

Effective date: 20080716

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20090331

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: 20080716

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

Ref country code: FR

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

Effective date: 20080731

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

Ref country code: DE

Payment date: 20140709

Year of fee payment: 14

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 60122164

Country of ref document: DE

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

Ref country code: DE

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

Effective date: 20160202