US20170159159A1 - Coil spring steel - Google Patents

Coil spring steel Download PDF

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Publication number
US20170159159A1
US20170159159A1 US15/156,826 US201615156826A US2017159159A1 US 20170159159 A1 US20170159159 A1 US 20170159159A1 US 201615156826 A US201615156826 A US 201615156826A US 2017159159 A1 US2017159159 A1 US 2017159159A1
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coil spring
steel
spring steel
content
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Sung Chul Cha
Jong Hwi PARK
Seung Hyun Hong
Kyu Ho Lee
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Hyundai Motor Co
Hyundai Steel Co
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Hyundai Motor Co
Hyundai Steel Co
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Assigned to HYUNDAI STEEL COMPANY, HYUNDAI MOTOR COMPANY reassignment HYUNDAI STEEL COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CHA, SUNG CHUL, HONG, SEUNG HYUN, LEE, KYU HO, PARK, JONG HWI
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • 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
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel 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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum

Definitions

  • the present disclosure relates to a coil spring steel having improved strength and fatigue life through carbide control.
  • a vehicle generally uses a high strength coil spring having a spring constant of 120 kg/s 2 , and ently, a high strength coil spring having a spring constant of 130 kg/s 2 is currently being developed.
  • a coil spring having a higher spring constant between 110 kg/s 2 to 130 kg/s 2 is used, a total weight of the vehicle can be reduced by reducing a spring diameter and the number of turns for winding the high strength spring coil, whereas sensitivity of the high strength spring coil increases due to corrosion after chipping and painting separation processes.
  • design margins are not secured for vehicles due to the reductionof the coil spring diameter, strength of the coil spring may decrease and a damage rate may increase,
  • the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to propose a coil spring steel having improved strength and fatigue life through carbide control.
  • a coil spring steel includes: 0.4 to 0.9 wt % of carbon (C); 1.3 to 2.3 wt % of silicon (Si); 0.5 to 1.2 wt % of manganese (Mn); 0.1 to 0.5 wt % of molybdenum (Mo); 0.05 to 0.80 wt % of nickel (Ni); 0.05 to 0.50 wt % of vanadium (V); 0.01 to 0.50 wt % of niobium (Nb); 0.05 to 0.30 wt % of titanium (Ti); 0.6 to 1.2 wt % of chromium (Cr); 0.0001 to 0.3 wt % of aluminum (Al); less than or equal to 0.3 wt % but greater than 0% of copper (Cu); less than or equal to 0.3 wt % but greater than 0% of nitrogen (N); 0.0001 to 0.0030 wt % of oxygen (O); and
  • the coil spring steel may have a tensile strength of 2150 MPa or more and a hardness of 690 HV or more.
  • a wire rod made of the coil spring steel may have a fatigue life of 280 thousand cycles or more under a condition of a bending moment of 20 kgfm and a load of 100 kgf.
  • a coil spring single-part made of the coil spring steel may have a complex corrosion fatigue life of 360 thousand cycles or more under a complex corrosion environment in which salt of 50 ⁇ 5 (g/L) is sprayed and to which a bending moment of 20 kgfm and a load of 100 kgf are applied.
  • the coil spring steel of the present disclosure can have improved strength and. fatigue life by controlling the contents of molybdenum (Mo), vanadium (V), niobium (Nb), titanium (Ti), and chromium (Cr) and generating carbide.
  • Mo molybdenum
  • V vanadium
  • Nb niobium
  • Ti titanium
  • Cr chromium
  • the coil spring steel of the present disclosure can have tensile strength increased by 10% and hardness increased by 17%, compared to existing steels including Fe-1.45Si-0.68Mn-0.71Cr-0.23Ni-0.08V-0.03Ti-0.23Cu-0.035Al-0.55
  • FIG. 1 is a graph illustrating a result of thermodynamic calculation. on mass fractions of components in cementite in a temperature range of 300° C. to 1600° C. according to an embodiment in the present disclosure.
  • FIG. 2 is a graph illustrating a result of thermodynamic calculation on amounts of all phases in a temperature range of 300° C. to 1600° C. according to an embodiment in the present disclosure.
  • a coil spring steel includes 0.4 to 0.9 wt % of carbon (C), 1.3 to 2.3 wt % of silicon (Si), 0.5 to 1.2 wt % of manganese (Mn), 0.1 to 0.5 wt % of molybdenum (Mo), 0.05 to 0.80 wt % of nickel (Ni), 0.05 to 0.50 wt % of vanadium (V), 0.01 to 0.50 wt % of niobium (Nb), 0.05 to 0.30 wt % of titanium (Ti), 0.6 to 1.2 wt % of chromium (Cr), 0.0001 to 0.3 wt % of aluminum (Al), less than or equal to 0.3 wt % (not including 0%) of copper (Cu), less than or equal to 0.3 wt % (not including 0%) of nitrogen (N), 0.0001 to 0.0030 wt % of oxygen (O), and a balance of
  • Carbon increases strength of steel after quenching the steel.
  • Carbide such as CrC, VC, or MoC is formed during the tempering of the steel.
  • the steel has improved temper-resistant and softening properties but has low toughness.
  • the carbon allows TiMoC nano-carbide to be formed and heated to a temperature of about 300° C.
  • the content of the carbon is less than 0.4 wt %, the strength of the steel insignificantly increases and. the fatigue strength thereof decreases.
  • the content of the carbon exceeds 0.9 wt %, large infusible carbide is present and the fatigue characteristics and durability life of the steel is deteriorated.
  • the steel has poor processability before being quenched. Therefore, the content of the carbon is limited to a range of 0.4 to 0.9 wt %.
  • Silicon improves elongation percentage of the steel.
  • the silicon suppresses variation in shape of the steel to improve the setting property thereof, and hardens the ferrite and martensite structures of the steel to increase heat resistance and hardenability thereof.
  • the content of the silicon is less than 1.3 wt %, the elongation percentage and setting property of the steel are insignificantly improved.
  • the content of the silicon exceeds 2.3 wt %, decarburization is caused due to infiltration of oxygen between the carbon and the structure.
  • the steel has poor processability due to an increase in hardness before being quenched. Therefore, the content of the silicon is limited to a range of 1.3 to 2.3 wt %.
  • Manganese improves the hardenability and strength of the steel.
  • the manganese is solidified in the base of the steel to increases the bending fatigue strength and quenching property thereof.
  • the manganese serves as a deoxidizer for generating oxide and suppresses the formation of inclusions such as aluminum oxide (Al 2 O 3 ).
  • Al 2 O 3 aluminum oxide
  • the manganese when the manganese is excessively included in the steel, it forms a MnS inclusion and causes high-temperature brittleness.
  • the quenching property of the steel is insignificantly improved.
  • the content of the manganese exceeds 1.2 wt %, the steel has poor proces ability before being quenched and has a reduced fatigue life due to centerline segregation and precipitation of the MnS inclusion. Therefore, the content of the manganese is limited to a range of 0.5 to 1.2 wt %.
  • Molybdenum forms fine precipitates such as TiMoC which is nano-carbide and improves the strength and fracture toughness of the steel.
  • the content of the molybdenum is less than 0.1 wt %, the fracture toughness of the steel is insignificantly improved.
  • the content of the molybdenum exceeds 0.5 wt %, the steel has poor processability and thus has low productivity. Therefore, the content of the molybdenum is limited to a range of 0.1 to 0.5 wt %.
  • Nickel improves the corrosion resistance and heat resistance of the steel and prevents low-temperature brittleness thereof.
  • the content of the nickel is less than 0.05 wt %, the corrosion resistance and heat resistance of the steel are insignificantly improved.
  • the content of the nickel exceeds 0.80 wt %, the steel has high-temperature brittleness. Therefore, the content of the nickel is limited to a range of 0.05 to 0.80 wt %.
  • Vanadium forms VC as a fine precipitate, and serves to improve the fracture toughness of the steel.
  • the VO as the fine precipitate suppresses movement of a grain boundary.
  • the vanadium is dissolved and solidified when the steel is austenitized and is precipitated when it is tempered, thereby causing secondary hardening.
  • the content of the vanadium is less than 0.05 wt %, the strength and fracture toughness of the steel are insignificantly improved.
  • the content of the vanadium exceeds 0.50 wt %, the steel has poor processahility, and thus, has low productivity, similarly to the molybdenum. Therefore, the content of the vanadium is limited to a range of 0.05 to 0.50 wt %.
  • Niobium forms fine precipitates, and improves the strength and fracture toughness of the steel.
  • the niobium refines the structure of the steel and hardens the surface thereof by nitrification.
  • the content of the niobium is less than 0.01 wt %, the strength and fracture toughness of the steel are insignificantly improved.
  • the content of the niobium exceeds 0.50 wt %, the steel has high-temperature brittleness. Therefore, the content of the niobium is limited to a range of 0.01 to 0.50 wt %.
  • Titanium forms fine precipitates such as TiMoC which is nano-carbide, and improves the strength and fracture toughness of the steel.
  • the titanium serves as a deoxidizer, and forms Ti 2 O 3 to replace the formation of Al 2 O 3 .
  • the content of the titanium is less than 0.05 wt %, the steel coarsens, and the effect of replacing the formation of Al 2 O 3 which is a main cause of fatigue deterioration is small.
  • the content of the titanium exceeds 0.30 wt %, only the above effect is increased, thereby causing an increase in cost. Therefore, the content of the titanium is limited to a range of 0.05 to 0.20 wt %.
  • Chromium is dissolved in the austenite structure of the steel and forms CrC carbide when the steel is tempered. Accordingly, the chromium improves the hardenability of the steel, accomplishes improvement in strength and grain refinement through suppression of steel softening, and improves the toughness of the steel.
  • the content of the chromium is less than 0.6 wt %, the strength and hardenability of the steel are insignificantly improved.
  • the content of the chromium exceeds 1.2 wt %, only the effect described in the titanium is increased, thereby causing an increase in cost. Therefore, the content of the chromium is limited to a range of 0.6 to 1.2 wt %.
  • Aluminum improves the strength and impact toughness of the steel. Since the aluminum is added to the steel together with Nb, Ti, and Mo, it is possible to reduce an added amount of vanadium for grain refinement and nickel for securing toughness which are expensive components.
  • the content of the aluminum is less than 0.0001 wt %, the strength and impact toughness of the steel are insignificantly improved.
  • the content of the aluminum exceeds 0.3 wt %, Al 2 O 3 which is a large square inclusion is formed, and this acts as a. fatigue origin, thereby deteriorating the durability of the steel. Therefore, the content of the aluminum is limited to a range of 0.0001 to 0.3 wt %.
  • Copper increases the strength of the steel and improves the corrosion resistance thereof as in nickel after the steel is tempered.
  • the content of the copper exceeds 0.3 wt %, alloy costs are increased. Therefore, the content of the copper is limited so as to be less than or equal to 0.3 wt %.
  • the content of the nitrogen exceeds 0.3 wt %, the quenching property of the steel may be deteriorated. Therefore, the content of the nitrogen is limited so as to be less than or equal to 0.3 wt %.
  • Oxygen is combined with silicon and aluminum to form a hard nonmetallic oxide inclusion, and causes deterioration of fatigue life of the steel.
  • the content of the oxygen may be low as possible as.
  • the content of the oxygen is limited. to a range of 0.0001 to 0.003 wt %.
  • a method for manufacturing a coil spring includes processing and filling a steel material, which includes 0.4 to 0.9 wt % of carbon (C), 1.3 to 2.3 wt % of silicon (Si), 0.5 to 1.2 wt % of manganese (Mn), 0.1 to 0.5 wt % of molybdenum (Mo), 0.05 to 0.80 wt. % of nickel (Ni), 0.05 to 0.50 wt % of vanadium (V), 0.01 to 0.50 wt.
  • a steel material which includes 0.4 to 0.9 wt % of carbon (C), 1.3 to 2.3 wt % of silicon (Si), 0.5 to 1.2 wt % of manganese (Mn), 0.1 to 0.5 wt % of molybdenum (Mo), 0.05 to 0.80 wt. % of nickel (Ni), 0.05 to 0.50 wt % of vanadium (V), 0.01 to 0.50 wt.
  • Nb niobium
  • Ti titanium
  • Cr chromium
  • Al aluminum
  • Cu copper
  • N nitrogen
  • O oxygen
  • Fe iron
  • the coil spring is made in such a manner that a control heat treatment process of maintaining the wire rod at certain high temperature for a certain time and then air cooling the same so as to refine crystal grains and homogenize structures thereof is performed, and quenching and tempering processes of giving strength and toughness to the homogenized wire rod are performed.
  • a tensile strength was measured using a standard tensile test specimen having a standard diameter of 4 mm according to KS B 0801, Korean Industrial Standards
  • the standard tensile test specimen was measured by a 200-ton tester according to KS B 0802.
  • Hardness was measured at 300 gf using a Micro-Vickers hardnesstester according to KS B 0811.
  • Wire rod fatigue life was measured using standard tensile test specimen. having a standard diameter of 4 mm according to KS B ISO 1143, using a bending fatigue tester having a maximum bending moment of 20 kgfm and a maximum load of 100 kgf.
  • a corrosion depth was measured using a complex environmental corrosion tester according to KS D 9502.
  • Table 1 shows components and the contents thereof according to examples and comparative examples.
  • Table 2 shows tensile strength, hardness, wire rod fatigue life, corrosion depth, single-part corrosion fatigue life, and complex corrosion fatigue life according to examples and comparative examples.
  • the contents of other components are controlled in the same range as those of the coil spring steel according to the examples, and only the content of nickel (Ni) is controlled so as to be less than or exceed that of the coil spring steel according to the examples.
  • the contents of other components are controlled in the same range as those of the coil spring steel according to the examples, and only the content of vanadium (V) is controlled so as to be less than or exceed that of the coil spring steel according to the examples.
  • the contents of other components are controlled in the same range as those of the coil spring steel according to the examples, and only the content of niobium (Nb) is controlled so as to be less than or exceed that of the coil spring steel according to the examples.
  • the contents of other components are controlled in the same range as those of the coil spring steel according to the examples, and only the content of titanium (Ti) is controlled so as to be less than or exceed that of the coil spring steel according to the examples.
  • the contents of other components are controlled in the same range as those of the coil spring steel according to the examples, and only the content of chromium (Cr) is controlled so as to be less than or exceed that of the coil spring steel according to the examples.
  • the contents of molybdenum (Mo), nickel (Ni), vanadium (V), niobium (Nb), titanium (Ti), and chromium (Cr) in the comparative examples 1 to 12 do not satisfy the limited content range of the components of the coil spring steel according to the examples. Therefore, it may be seen that the tensile strength and the hardness in the comparative examples 1 to 12 are lower compared to those in the examples 1 to 3.
  • the wire rod fatigue life, single-part corrosion fatigue life, and complex corrosion fatigue life in the comparative examples 1 to 12 are poor compared to those in the examples 1 to 3. It may be seen that since the corrosion depth is deeper compared to that in the examples 1 to 3, corrosion performance is lowered.
  • the molybdenum, vanadium, niobium, titanium, and chromium are components which react with carbon to form carbide, and generate MoC, VC, NbC, TiC, and CrC, respectively.
  • carbide Through such uniform distribution of carbide, the tensile strength and hardness of the steel are increased, and the wire rod fatigue life, single-part corrosion fatigue life, and complex corrosion fatigue life thereof related to durability and corrosion resistance are increased.
  • FIG. 1 is a graph illustrating a result of thermodynamic calculation on mass fractions of components in cementite in the temperature range of 300 to 1600° C. in the coil spring steel including Fe-1.6Si-0.7Mn-0.8Cr-0.3Ni-0.3Mo-0.3V-0.1Nb-0.09Ti-0.550 (including small amounts of other Al, Cu, N, and O) according to the present disclosure.
  • lr may be seen that the complex behaviors of eight components are generated for each temperature in the cementite and fine carbides such as MoC, VC, NbC, TiC, and CrC are uniformly distributed.
  • FIG. 2 is a graph illustrating a result of thermodynamic calculation on amounts of all phases in the temperature range of 300 to 1600° C. in the coil spring steel including Fe-1.6Si-0.7Mn-0.8Cr-0.3Ni-0.3Mo-0.3V-0.1Nb-0.09Ti-0.55C (including small amounts of other Al, Cu, N, and O) according to the present disclosure. It may be seen that various carbides such as MS-ETA and M7C3 in addition to FCC-Al (Austenite), BCC-A2 (Ferrite), and cementite are formed, and the strength and fatigue life of the steel are improved.
  • various carbides such as MS-ETA and M7C3 in addition to FCC-Al (Austenite), BCC-A2 (Ferrite), and cementite are formed, and the strength and fatigue life of the steel are improved.
  • the coil spring steel of the present disclosure can have improved strength and fatigue life by controlling the contents of molybdenum (Mo), vanadium (V), niobium (Nb), titanium (Ti), and chromium (Cr) and generating carbide.
  • Mo molybdenum
  • V vanadium
  • Nb niobium
  • Ti titanium
  • Cr chromium
  • the coil spring steel of the present disclosure can have tensile strength increased by 10% and hardness increased by 17%, compared to existing steels including Fe-1.45Si-0.68Mn-0.71Cr-0.23Ni-0.08V-0.03Ti-0.23Cu-0.035Al-0.55C.

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US15/156,826 2015-12-04 2016-05-17 Coil spring steel Abandoned US20170159159A1 (en)

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Publication number Priority date Publication date Assignee Title
US20100224287A1 (en) * 2006-01-23 2010-09-09 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength spring steel excellent in brittle fracture resistance and method for producing same

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CN100480411C (zh) * 2004-11-30 2009-04-22 新日本制铁株式会社 高强度弹簧用钢及钢线
FR2894987B1 (fr) * 2005-12-15 2008-03-14 Ascometal Sa Acier a ressorts, et procede de fabrication d'un ressort utilisant cet acier, et ressort realise en un tel acier
JP5114665B2 (ja) * 2006-03-31 2013-01-09 新日鐵住金株式会社 高強度ばね用熱処理鋼

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100224287A1 (en) * 2006-01-23 2010-09-09 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) High-strength spring steel excellent in brittle fracture resistance and method for producing same

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