EP0462779A2 - Procédé de traitement thermique d'acier, notamment d'acier pour ressorts - Google Patents

Procédé de traitement thermique d'acier, notamment d'acier pour ressorts Download PDF

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Publication number
EP0462779A2
EP0462779A2 EP91305456A EP91305456A EP0462779A2 EP 0462779 A2 EP0462779 A2 EP 0462779A2 EP 91305456 A EP91305456 A EP 91305456A EP 91305456 A EP91305456 A EP 91305456A EP 0462779 A2 EP0462779 A2 EP 0462779A2
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EP
European Patent Office
Prior art keywords
plate
cold
steel
rolled strip
temperature
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
EP91305456A
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German (de)
English (en)
Other versions
EP0462779B1 (fr
EP0462779A3 (en
Inventor
Tsunetoshi c/o Tekkokenkyusho Suzaki
Tomoyoshi c/o Tekkokenkyusho Iwao
Teruo Nisshin Steel Co. Ltd. Tanaka
Toshiro c/o Tekkokenkyusho Yamada
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.)
Nippon Steel Nisshin Co Ltd
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Nisshin Steel 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
Priority claimed from JP15879090A external-priority patent/JP2961666B2/ja
Priority claimed from JP2507691A external-priority patent/JP2952862B2/ja
Priority claimed from JP2507791A external-priority patent/JP2823965B2/ja
Application filed by Nisshin Steel Co Ltd filed Critical Nisshin Steel Co Ltd
Publication of EP0462779A2 publication Critical patent/EP0462779A2/fr
Publication of EP0462779A3 publication Critical patent/EP0462779A3/en
Application granted granted Critical
Publication of EP0462779B1 publication Critical patent/EP0462779B1/fr
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Expired - Lifetime legal-status Critical Current

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    • 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
    • C21D9/02—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for springs
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/02—Hardening by precipitation
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—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
    • 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
    • C22C38/34—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling

Definitions

  • the present invention relates to a method of making steel which is useful in springs, such as the diaphragm spring component in clutches for motor vehicles.
  • the diaphragm spring is made of carbon tool steel such as SK5 (Japanese Industrial Standard). However, springs of carbon steel can relax quickly, in that they may become inoperative when the temperature thereof reaches or exceeds the high environmental temperature of 150°C.
  • An object of the present invention is to provide a method of making steel having a property resisting high temperature, whereby a spring made of the steel is more resistant to relaxation at relatively high temperatures.
  • Another object of the present invention is to provide steel which may be quickly quenched at a low temperature, thereby preventing significant endurance reduction in the steel.
  • the method for making steel comprises hot-rolling steel material consisting essentially by weight of from 0.4 % to 0.8 % carbon, from 0.5 % to 2.5 % silicon, from 0.3 % to 2.0 % manganese, from 0.1 % to 1.5 % chromium, from 0.1 % to 0.5 % molybdenum, and the remainder iron and inevitable impurities to form a plate, annealing the hot-rolled plate, cold-rolling the annealed hot-rolled plate at rolling reduction of 10 % to 80 %, annealing the cold-rolled plate at a temperature below Ac1 critical point, heating the annealed cold-rolled plate at a temperature above Ac3 critical point for a time sufficient to austenitize carbide, cooling the heated cold-rolled plate at a speed higher than a lower critical cooling speed, heating the cooled cold-rolled plate for a time necessary for precipitating carbide and then cooling it to a room temperature.
  • the lower critical cooling speed is a speed above which the austenite is fully transformed to the martensite.
  • molybdenum carbide is finely precipitated, thereby preventing the dislocation migration which causes the relaxation of the spring at high temperature.
  • the heating is preferably performed at a temperature between 450°C and 600°C for a time sufficient to precipitate the carbide.
  • the silicon content and chromium content are preferably selected so as to satisfy the equation: -7 ⁇ 4xSi(%)-10xCr(%) ⁇ 5.
  • the heating of the cooled cold-rolled plate is preferably performed so as to provide an annealed hardness between HV400 and HV550.
  • the annealing of the cold-rolled plate is preferably performed at a temperature between 550°C and 730°C, thereby providing carbide having an average grain diameter less than 2 ⁇ m.
  • the figure is a graph showing relationship between heating temperature and hardness of steel.
  • Carbon is effective in increasing the strength of steel. In order to obtain a strength necessary for the the spring, carbon content of 0.4 % or more by weight must be included. However, if carbon is included in excess of 0.8 %, quenching crack and reduction of toughness of steel occur. Therefore the carbon is included in the range 0.4 % to 0.8 % by weight.
  • the material is tempered at high temperature. Silicon is added to prevent the strength from reducing due to the high temperature tempering. It is necessary to add silicon of 0.5 % or more by weight. If the silicon content exceeds 2.5 %, internal oxidation and decarburization which are unfavourable to the spring occur, and graphitization is enhanced in the hot rolling and annealing.
  • Manganese is effective in deoxidizing steel and in increasing the hardenability of the steel, if the manganese is included at 0.3 % or more by weight. If the manganese content exceeds 2.0 %, toughness of the steel reduces significantly after quenching and tempering.
  • Chromium acts to restrict the graphitization and the internal oxidation which are enhanced by silicon, and is effective in increasing the hardenability as is effected by manganese, if chromium is included at 0.1 % or more by weight. If the chromium content exceeds 1.5 %, toughness of the steel reduces after quenching and tempering.
  • Si content and Cr content are most preferably determined to satisfy the following equation, thereby preventing decarburization and graphitization. -7 ⁇ 4xSi(%)-10xCr(%) ⁇ 5 (1)
  • the molybdenum included in the steel of the present invention forms carbide in the steel after cold rolling and annealing.
  • the carbon becomes solid solution in austenite when the steel is heated over the Ac3 critical point. Consequently, the austenite is transformed into martensite after quenching, and carbide separates finely upon tempering at high temperature, thereby significantly increasing endurance whilst withstanding against relaxation.
  • it is necessary to include molybdenum of at least 0.1 % but no more than 0.5 % by weight. If the molybdenum content exceeds 0.5 %, a large amount of carbide remains without becoming solid solution in austenite when the steel is heated above the Ac3 critical point.
  • vanadium and niobium if included in the steel of the present invention become carbide after the cold rolling and annealing thereof. Remaining vanadium and niobium without becoming solid solution in austenite act to prevent austenite grain from growing.
  • solid solution of vanadium and niobium in austenite are in solid solution in martensite when quenching, and precipitate finely as carbide when tempering, thereby enhancing endurance whilst withstanding against relaxation.
  • vanadium and/or niobium each in an amount of 0.05 % or more are necessary. If the individual content of either or both exceeds 0.5 %, the quantity of undissolved carbide in austenite increases when the steel is heated above Ac3 point, thereby reducing fatigue strength of the steel.
  • the steel spring is fatigued by repeated bending or twisting.
  • Existence of hard inclusions such as aluminum aggravates this fatigue.
  • the aluminium content of the steel is preferably less than 0.020 weight percent.
  • the annealing after the cold rolling is performed at a temperature above 730°C (Ac1 critical point), spheroidized grain of carbide becomes coarse. Consequently, it takes a long time to transform the carbide to austenite, resulting in increase of decarburization causing deterioration of spring characteristic. Therefore, the annealing after the cold rolling is carried out at a temperature below the Ac1 point. If the annealing temperature is lower than 550°C, the hardness increases, so that the formability of the material reduces. Therefore, the annealing temperature is between 550°C and 730°C.
  • the average grain diameter of carbide after the annealing is less than 2 ⁇ m, carbide is easily dissolved austenite at quenching. Therefore, it is necessary to maintain the average grain diameter of carbide to a value smaller than 2 ⁇ m for effectively performing the quenching.
  • the strip is heated at a temperature higher than the critical point Ac3 for a time sufficient for austenitizing the spheroidal carbide, after which it is cooled at a speed higher than a lower critical cooling speed, namely quenching. Thereafter, the strip is heated at a temperature between 450°C and 600°C for a time to precipitate fine carbide and cooled to a room temperature (that is tempering). At the quenching, the parent material is austenitized by heating it over the Ac3 point, and then carbon and other elements are dissolved to martensite by cooling at a speed higher than the lower critical cooling speed.
  • Table 1 shows contents of steels.
  • a to F are steels of the present invention
  • G to L are comparative steels.
  • Each of the steels A to F is made into a hot-rolled plate of 3.5 mmt by ordinary hot rolling and then the plate is annealed and cold rolled at a rolling reduction between 5 % and 90 %. Thereafter, the steel is annealed at 700°C below the Ac1 point for 10 hours, and is soaked at 900°C above the Ac3 point for a period necessary to provide remaining carbide ratio below 1 % by weight. Thereafter, the steel is quenched into oil.
  • Table 2 shows results of tests for edge crack and depth of decarburization.
  • edge crack occurs. If the rolling reduction is smaller than 10 %, carbide becomes coarse. Consequently, it takes a long time to dissolve carbide into austenite, so that the depth of decarburization increases significantly.
  • Each of the steels A to F is made into a hot-rolled plate of 3.5 mmt by ordinary hot rolling and annealed and cold rolled at rolling reduction of 35 % to form a cold rolled plate of 2.3 mm. Thereafter, the steel is annealed once at 700°C for 10 hours, and is heated at a temperature between 850°C and 900°C for 10 minutes. Thereafter, the steel is quenched into oil and tempered at a temperature between 420°C and 630°C for 30 minutes.
  • a relaxation test was performed in order to estimate endurance against relaxation. The test was carried out at 350°C, initial 1.0 % strain, holding time of 12 hours. Load reduction after the test was regarded as relaxation rate.
  • Table 3 shows the result of the relaxation test. Since comparative example G is smaller than the present invention in carbon content, comparative example 1 is smaller in silicon content, comparative example J is in manganese content, and K is in chromium content, each of these steels has low strength so that the relaxation rate thereof is high. Although the comparative example H has a large carbon content, the relaxation rate is not largely reduced. Since the comparative example L has no molybdenum, the carbide of which is effective to increase the endurance, relaxation rate is very high. Although each of comparative examples A', D' and F' has the same ingredient content as the present invention, the tempering temperature is out of the range of the present invention. Consequently, the relaxation rate is not largely reduced.
  • each steel according to the present invention has a very low relaxation rate comparing with the comparative examples, which means that the steel has a high endurance withstanding against the relaxation.
  • Embodiments A to G in Table 4 are steels of the present invention and H to L are comparative steels.
  • Each of the steels in the table was hot-rolled to provide a hot-rolled plate having a thickness of 3.5 mmt, and then annealing the hot-rolled plate.
  • the plate was cold rolled at rolling reduction of 35 % to prepare a cold-rolled plate of 2.3 mmt thickness.
  • the cold-rolled plate was annealed at a temperature between 650°C and 750°C for 10 hours to provide a test piece.
  • Hardenability test was performed in such a manner that the test piece was rapidly heated to 850°C at the rate of 140C o /sec, heated from 850°C to a test temperature between 900°C and 1100°C at the rate of 30C o /sec, and then rapidly cooled immediately after the heating without taking a holding time. The hardenability was estimated by the hardness of the test piece after the quenching. Results of the test are shown in the attached figure.
  • the test piece A having ingredient contents according to the present invention has an average grain diameter of carbide less than 2 ⁇ m when annealed at 650°C and 700°C. Even if the test piece A is heated to the lowest temperature 900°C, the hardness becomes the higher value. However, if it is annealed at 750°C so that the average grain diameter exceeds 2 ⁇ m, the hardness does not reach the highest value unless the quenching temperature is elevated up to 950°C.
  • the comparative example H has a SICR value of -7.42 out of the range of the present invention. Consequently a large amount of chromium remains in carbide after the annealing. Accordingly, the steel must be heated up to 1000°C in order to obtain the higher hardness, although the average grain diameter is smaller than 2 ⁇ m.
  • Fatigue test and relaxation test piece are estimated as follows.
  • the cold-rolled plate having 2.3 mm thickness is annealed at 680°C for 10 hours, and then heated at 900°C and quenched. Thereafter, a plurality of the plates are tempered at various temperatures for 30 minutes.
  • the fatigue test was performed in alternating plane bending fatigue. The result of the test is shown in Table 5.
  • the steel A of the present invention has a hardness approximately equal to the comparative example I, the steel A is superior to the comparative example I in fatigue strength. This is caused by the fact that the aluminum content of the steel A is less than 0.020 weight percent, which means hard inclusion causing fatigue fracture is small.
  • the steel G has the same fatigue characteristic as steel A.
  • the comparative steel J has a small Cr content compared with Si content, so that SICR value is 7.50 out of the range of the present invention, producing graphite at annealing.
  • SICR value is 7.50 out of the range of the present invention, producing graphite at annealing.
  • decarburization increased.
  • the fatigue characteristic is inferior to the steels A and G.
  • a to G are steels of the present invention
  • H to L are comparative steels.
  • Each of the steels in the table was hot rolled to provide a hot-rolled plate having a thickness of 3.5 mmt, and the hot-rolled plate was then annealed.
  • the plate was cold rolled at rolling reduction of 35 % to prepare a cold-rolled plate of 2.3 mmt thickness.
  • the cold-rolled plate was annealed at 680°C for 10 hours, and then heated at a temperature between 850°C and 900°C for 10 minutes and quenched into oil. All plates were tempered at various temperatures for 30 minutes.
  • the fatigue test was performed in alternating plane bending fatigue. The result of the test is shown in Table 8.
  • the steel E of the present invention has a hardness approximately equal to the comparative example I, the steel E is superior to the comparative example I in fatigue strength due to the lower aluminium content.
  • the fatigue strength may reduce if the annealed hardness exceeds HV550.
  • Test temperature was 350°C, initial strain 1.0 %, and holding time 12 hours. Table 9 shows the test results.
  • Comparative steels H and J have small C content and Si content, and hence they have high relaxation rates, respectively. Since comparative steel K has no Mo, it has a high relaxation rate. Even if each of steels A, D, E and G include components within the present invention, the relaxation rate is not significantly reduced if the tempering temperature increases and hardness is lower than an annealed hardness of HV400, as shown in comparative examples II.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Articles (AREA)
EP91305456A 1990-06-19 1991-06-17 Procédé de traitement thermique d'acier, notamment d'acier pour ressorts Expired - Lifetime EP0462779B1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP158790/90 1990-06-19
JP15879090A JP2961666B2 (ja) 1990-06-19 1990-06-19 耐温間へたり性に優れたばね用鋼の製造方法
JP2507691A JP2952862B2 (ja) 1991-01-28 1991-01-28 焼入れ性，耐温間へたり性に優れたバネ用鋼の製造方法
JP2507791A JP2823965B2 (ja) 1991-01-28 1991-01-28 ダイヤフラムスプリング用鋼の製造方法
JP25077/91 1991-01-28
JP25076/91 1991-01-28

Publications (3)

Publication Number Publication Date
EP0462779A2 true EP0462779A2 (fr) 1991-12-27
EP0462779A3 EP0462779A3 (en) 1993-09-01
EP0462779B1 EP0462779B1 (fr) 1996-09-11

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EP91305456A Expired - Lifetime EP0462779B1 (fr) 1990-06-19 1991-06-17 Procédé de traitement thermique d'acier, notamment d'acier pour ressorts

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EP (1) EP0462779B1 (fr)
KR (1) KR930012177B1 (fr)
AU (1) AU633737B2 (fr)
CA (1) CA2044639C (fr)
DE (1) DE69121982T2 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0672761A2 (fr) * 1994-02-17 1995-09-20 Uddeholm Strip Steel Aktiebolag Utilisation d'un alliage d'acier
GB2352726A (en) * 1999-08-04 2001-02-07 Secr Defence A steel and a heat treatment for steels
EP1347072A1 (fr) * 2000-12-20 2003-09-24 Kabushiki Kaisha Kobe Seiko Sho Tige de fil d'acier pour ressort etire dur, tige de fil etire pour ressort etire dur, ressort etire dur et procede de production de ce ressort
EP1491647A1 (fr) * 2002-04-02 2004-12-29 Kabushiki Kaisha Kobe Seiko Sho Fil d'acier pour un ressort etire presentant d'excellentes caracteristiques de resistance a la fatigue et au tassement
WO2005021190A1 (fr) * 2003-08-28 2005-03-10 Toyota Jidosha Kabushiki Kaisha Alliage fritte a base de fer et sa methode de fabrication
EP1612287A1 (fr) * 2003-03-28 2006-01-04 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Acier pour ressort presentant une excellente resistance a la fatigue et d'excellentes caracteristiques de fatigue
EP2028285A1 (fr) * 2006-06-09 2009-02-25 Kabushiki Kaisha Kobe Seiko Sho Acier pour ressort à propreté élevée ayant des caractéristiques excellentes de fatigue et ressort à propreté élevée
EP2682493A1 (fr) * 2011-03-04 2014-01-08 NHK Spring Co.,Ltd. Ressort et son procédé de fabrication
CN106202937A (zh) * 2016-01-28 2016-12-07 西北工业大学 M50钢锻造组织中碳化物尺寸预测方法
SE1950679A1 (en) * 2019-06-07 2020-12-08 Voestalpine Prec Strip Ab Steel strip for flapper valves

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2932943B2 (ja) * 1993-11-04 1999-08-09 株式会社神戸製鋼所 高耐食性高強度ばね用鋼材

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FR1290235A (fr) * 1961-02-28 1962-04-13 Ct Tech De L Ind Horlogere Procédé de fabrication de ressorts ou matériaux pour ressorts en acier et ressorts ou matériaux obtenus par ce procédé, en particulier ressorts pour mouvements d'horlogerie
US4770721A (en) * 1981-08-11 1988-09-13 Aichi Steel Works, Ltd. Process of treating steel for a vehicle suspension spring to improve sag-resistance
JPH02240240A (ja) * 1989-03-10 1990-09-25 Aisin Seiki Co Ltd 自動車用クラッチのダイヤフラムスプリング

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Publication number Priority date Publication date Assignee Title
JPS5827955A (ja) * 1981-08-11 1983-02-18 Aichi Steel Works Ltd 焼入性、耐へたり性の優れたばね用鋼
AU547648B2 (en) * 1981-09-30 1985-10-31 Aichi Steel Works Ltd. Steel for a vehicle suspension spring

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1290235A (fr) * 1961-02-28 1962-04-13 Ct Tech De L Ind Horlogere Procédé de fabrication de ressorts ou matériaux pour ressorts en acier et ressorts ou matériaux obtenus par ce procédé, en particulier ressorts pour mouvements d'horlogerie
US4770721A (en) * 1981-08-11 1988-09-13 Aichi Steel Works, Ltd. Process of treating steel for a vehicle suspension spring to improve sag-resistance
JPH02240240A (ja) * 1989-03-10 1990-09-25 Aisin Seiki Co Ltd 自動車用クラッチのダイヤフラムスプリング

Non-Patent Citations (1)

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Title
PATENT ABSTRACTS OF JAPAN vol. 14, no. 559 (C-787)12 December 1990 & JP-A-02 240 240 ( AISIN SEIKI ) 25 September 1990 *

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0672761A3 (fr) * 1994-02-17 1995-11-08 Uddeholm Steel Strip Utilisation d'un alliage d'acier.
EP0672761A2 (fr) * 1994-02-17 1995-09-20 Uddeholm Strip Steel Aktiebolag Utilisation d'un alliage d'acier
US6884306B1 (en) 1999-08-04 2005-04-26 Qinetiq Limited Baintic steel
GB2352726A (en) * 1999-08-04 2001-02-07 Secr Defence A steel and a heat treatment for steels
EP1347072A1 (fr) * 2000-12-20 2003-09-24 Kabushiki Kaisha Kobe Seiko Sho Tige de fil d'acier pour ressort etire dur, tige de fil etire pour ressort etire dur, ressort etire dur et procede de production de ce ressort
EP1347072A4 (fr) * 2000-12-20 2005-08-31 Kobe Steel Ltd Tige de fil d'acier pour ressort etire dur, tige de fil etire pour ressort etire dur, ressort etire dur et procede de production de ce ressort
US7597768B2 (en) 2002-04-02 2009-10-06 Kabushiki Kaisha Kobe Seiko Sho Steel wire for hard drawn spring excellent in fatigue strength and resistance to settling, and hard drawn spring and method of making thereof
US7763123B2 (en) 2002-04-02 2010-07-27 Kabushiki Kaisha Kobe Seiko Sho Spring produced by a process comprising coiling a hard drawn steel wire excellent in fatigue strength and resistance to setting
EP1491647A4 (fr) * 2002-04-02 2005-07-06 Kobe Steel Ltd Fil d'acier pour un ressort etire presentant d'excellentes caracteristiques de resistance a la fatigue et au tassement
EP1491647A1 (fr) * 2002-04-02 2004-12-29 Kabushiki Kaisha Kobe Seiko Sho Fil d'acier pour un ressort etire presentant d'excellentes caracteristiques de resistance a la fatigue et au tassement
EP1612287A1 (fr) * 2003-03-28 2006-01-04 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Acier pour ressort presentant une excellente resistance a la fatigue et d'excellentes caracteristiques de fatigue
EP1612287A4 (fr) * 2003-03-28 2007-11-21 Kobe Steel Ltd Acier pour ressort presentant une excellente resistance a la fatigue et d'excellentes caracteristiques de fatigue
US7615186B2 (en) 2003-03-28 2009-11-10 Kobe Steel, Ltd. Spring steel excellent in sag resistance and fatigue property
WO2005021190A1 (fr) * 2003-08-28 2005-03-10 Toyota Jidosha Kabushiki Kaisha Alliage fritte a base de fer et sa methode de fabrication
US7749298B2 (en) 2003-08-28 2010-07-06 Toyota Jidosha Kabushiki Kaisha Iron-based sintered alloy and manufacturing method thereof
US8613809B2 (en) 2006-06-09 2013-12-24 Kobe Steel, Ltd. High cleanliness spring steel and high cleanliness spring excellent in fatigue properties
EP2028285A4 (fr) * 2006-06-09 2011-04-20 Kobe Steel Ltd Acier pour ressort à propreté élevée ayant des caractéristiques excellentes de fatigue et ressort à propreté élevée
EP2028285A1 (fr) * 2006-06-09 2009-02-25 Kabushiki Kaisha Kobe Seiko Sho Acier pour ressort à propreté élevée ayant des caractéristiques excellentes de fatigue et ressort à propreté élevée
EP2682493A1 (fr) * 2011-03-04 2014-01-08 NHK Spring Co.,Ltd. Ressort et son procédé de fabrication
EP2682493A4 (fr) * 2011-03-04 2014-08-27 Nhk Spring Co Ltd Ressort et son procédé de fabrication
US9341223B2 (en) 2011-03-04 2016-05-17 Nhk Spring Co., Ltd. Spring and manufacture method thereof
CN106202937A (zh) * 2016-01-28 2016-12-07 西北工业大学 M50钢锻造组织中碳化物尺寸预测方法
CN106202937B (zh) * 2016-01-28 2018-10-19 西北工业大学 M50钢锻造组织中碳化物尺寸预测方法
SE1950679A1 (en) * 2019-06-07 2020-12-08 Voestalpine Prec Strip Ab Steel strip for flapper valves
WO2020246937A1 (fr) * 2019-06-07 2020-12-10 Voestalpine Precision Strip Ab Bande d'acier pour clapets à battant
SE543422C2 (en) * 2019-06-07 2021-01-12 Voestalpine Prec Strip Ab Steel strip for flapper valves
EP3980571A4 (fr) * 2019-06-07 2023-11-22 voestalpine Precision Strip AB Bande d'acier pour clapets à battant

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DE69121982D1 (de) 1996-10-17
EP0462779B1 (fr) 1996-09-11
CA2044639A1 (fr) 1991-12-20
DE69121982T2 (de) 1997-01-30
AU633737B2 (en) 1993-02-04
KR930012177B1 (ko) 1993-12-24
CA2044639C (fr) 2001-08-28
AU7837391A (en) 1992-01-09
KR920000959A (ko) 1992-01-29
EP0462779A3 (en) 1993-09-01

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