WO2011078165A1 - Acier à ressorts à haute résistance - Google Patents

Acier à ressorts à haute résistance Download PDF

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Publication number
WO2011078165A1
WO2011078165A1 PCT/JP2010/073003 JP2010073003W WO2011078165A1 WO 2011078165 A1 WO2011078165 A1 WO 2011078165A1 JP 2010073003 W JP2010073003 W JP 2010073003W WO 2011078165 A1 WO2011078165 A1 WO 2011078165A1
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spring steel
strength
spring
steel
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PCT/JP2010/073003
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English (en)
Japanese (ja)
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清佳 永松
知忠 丸尾
吉原　直
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株式会社神戸製鋼所
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Priority to ES10839395T priority Critical patent/ES2709515T3/es
Priority to US13/511,541 priority patent/US20120285585A1/en
Priority to EP10839395.0A priority patent/EP2518175B1/fr
Priority to BR112012014178A priority patent/BR112012014178A2/pt
Priority to CN201080039360.2A priority patent/CN102482743B/zh
Publication of WO2011078165A1 publication Critical patent/WO2011078165A1/fr
Priority to US15/286,065 priority patent/US20170022580A1/en

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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
    • C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C21D9/02—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
    • C22C38/002—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
    • C22C38/02—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
    • C22C38/04—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
    • C22C38/34—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
    • C22C38/46—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
    • C22C38/50—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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • 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
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
    • C21D7/06—Modifying the physical properties of iron or steel by deformation by cold working of the surface by shot-peening or the like

Definitions

  • the present invention relates to a spring steel (spring steel) useful as a material for a coil spring, and more particularly to a spring steel used when manufacturing a coil spring, which has a tensile strength as it is quenched.
  • the present invention relates to a steel for springs of 1900 MPa class.
  • Such a coil spring is generally manufactured by drawing spring steel (wire), polishing, heating, coiling hot, quenching and tempering, and setting.
  • the quenching and tempering treatment after hot coiling is performed to adjust the strength of the spring.
  • heat treatment such as quenching and tempering, a large amount of CO 2 is exhausted.
  • CO 2 reduction has been strongly demanded as one of the measures for preventing global warming for the purpose of reducing the burden on the global environment. Therefore, it is required to reduce the CO 2 emission amount even in the manufacturing process of the coil spring.
  • Patent Document 1 proposes a steel for a stabilizer that is water-quenched immediately after hot forming and has improved normal temperature toughness and low temperature toughness while still being water-quenched without tempering.
  • the component composition is adjusted to a low C-high Mn-Cr system or a low C-high Mn-B-Cr system with one or more of Ti, V, and Nb added.
  • the stabilizer that is the subject of this Patent Document 1 is different from the coiling spring in the technical field.
  • the strength level is an 800 MPa class in which corrosion fatigue characteristics do not become a problem, and a high strength region where compatibility with the corrosion fatigue characteristics is required. (For example, a 1900 MPa class) spring is not related.
  • the strength of steel materials increases with increasing hardness, and toughness decreases with increasing hardness.
  • the toughness decreases when the strength of the steel material increases, but the spring material is required to have fracture characteristics that can withstand the severe use environment of the spring, and even in springs such as suspension springs with increased strength, In particular, it is necessary to ensure low temperature toughness, which is important for use in cold regions.
  • Patent Document 2 discloses that ductility and toughness have been improved in high-strength spring steel by adjusting various components
  • Patent Document 3 has improved hardness and toughness by adjusting various components. It is disclosed that a combined spring steel is obtained.
  • both Patent Documents 2 and 3 focus only on toughness at room temperature, and do not consider low-temperature toughness.
  • the toughness at low temperature is usually inferior to the toughness at normal temperature, and considering the normal temperature toughness disclosed in Patent Documents 2 and 3, the low-temperature toughness in the techniques of Patent Documents 2 and 3 is insufficient.
  • the present invention has been made paying attention to the above circumstances, and its purpose is to provide high strength and good corrosion fatigue characteristics even when tempering after quenching is omitted when processing into a coil spring.
  • An object of the present invention is to provide a spring steel that can produce a coil spring that is compatible and has excellent low-temperature toughness.
  • Another object of the present invention is to provide a spring obtained from this spring steel.
  • the high-strength spring steel according to the present invention that can solve the above-mentioned problems is C: 0.15 to 0.40% (meaning mass%, the same applies hereinafter), Si: 1 to 3.5%, Selected from the group consisting of Mn: 0.20 to 2.0%, Ti: 0.005 to 0.10%, Nb: 0.005 to 0.05%, and V: 0.25% or less At least one selected from the group consisting of Cr: 0.05 to 1.20%, P: 0.030% or less, S: 0.02% or less, the balance being iron and inevitable impurities, ), The carbon equivalent Ceq 1 is 0.55 or less.
  • the spring steel according to the present invention includes (a) Ni: 0.05 to 2% and Cu: 0.05 to 0.50%, (b) Ni: 0.15 to 2% and Cu: 0 as necessary. 0.05 to 0.50%, (c) B: 0.005% or less and / or Mo: 0.60% or less may be contained.
  • the spring steel of the present invention is selected from the group consisting of Ti: 0.035 to 0.10%, Nb: 0.005 to 0.05%, and V: 0.05 to 0.25%. It is also preferable that at least one kind is contained and the crystal grain size after quenching is 7.5 or more.
  • the spring steel is hot-coiled, quenched and quenched, and then set with the temper omitted, a spring that can achieve both of the above characteristics can be manufactured.
  • the spring steel of the present invention appropriately controls the element amount and blending balance of a specific alloy element, the tempering process after quenching is omitted when a coil spring is manufactured using this spring steel. Thus, it is possible to manufacture a spring having both high strength and good corrosion fatigue properties while still being quenched, and further having good low temperature toughness.
  • FIG. 1 is a graph showing the relationship between the carbon equivalent (Ceq 1 ) of the test piece obtained in Example 1 and the hydrogen embrittlement crack life.
  • FIG. 2 is a graph showing the relationship between the tensile strength and the low temperature toughness (vE- 50 ) of the test piece obtained in Example 2.
  • the present inventors When producing springs by coiling spring steel, the present inventors omit the tempering after quenching performed after coiling to achieve both high strength and good corrosion fatigue properties, and are excellent in low temperature toughness.
  • the types of basic alloy elements to be contained in the spring steel are limited to at least one of C, Si, Mn, Cr and Ti, Nb and V, or (i) Ni and Cu are further added to these element groups.
  • the spring steel of the present invention is particularly characterized in that the amount of C is lower than the amount of C used in ordinary spring steel.
  • the amount of C is lower than the amount of C used in ordinary spring steel.
  • the amount of carbide precipitated in the steel can be reduced, so that tempering after quenching that is performed in a normal spring manufacturing process can be omitted. That is, as described above, the spring is usually manufactured by drawing and polishing spring steel (wire rod), heating, hot coiling, quenching and tempering, and setting. After the setting, if necessary, coating is performed after shot peening.
  • the spring steel of the present invention has a reduced amount of C, the strength of the spring can be secured even if setting is performed without the tempering after quenching.
  • Si and Mn are positively added.
  • Si and Mn are easily available elements, and stable supply can be maintained even if the amount of Si and Mn is increased.
  • Si and Mn have the effect
  • the component composition of the spring steel is designed as follows, and the carbon equivalent Ceq 1 represented by the following formula (1) is set to 0.55 or less.
  • [] represents the content (% by mass) of each element in the steel.
  • the reason for setting the addition amount of each element and the reason for defining the carbon equivalent Ceq 1 are as follows.
  • the reason why C is 0.15% or more is to improve the hardenability and ensure the strength.
  • the reason why C is set to 0.40% or less is to prevent deterioration of toughness and corrosion fatigue characteristics.
  • the lower limit of the C amount is preferably 0.2% or more, more preferably 0.25% or more, and the upper limit of the C amount is preferably 0.35% or less, more preferably 0.34% or less, particularly preferably. It is 0.33% or less.
  • Si is 1% or more
  • Si is preferably 1.5% or more and 3.0% or less, more preferably 1.80% or more and 2.5% or less.
  • Mn is 0.20% or more
  • the hardenability is improved and the strength can be secured.
  • the formation of sulfide inclusions can suppress grain boundary embrittlement due to S and improve toughness and corrosion fatigue characteristics.
  • Mn is 2.0% or less, it is possible to prevent a supercooled structure from being generated and deteriorate toughness and corrosion fatigue characteristics.
  • production and coarsening of an excessive sulfide type inclusion can be suppressed, and it can prevent that toughness and a corrosion fatigue characteristic deteriorate.
  • the lower limit of the Mn amount is preferably 0.5% or more, more preferably 0.80% or more
  • the upper limit of the Mn amount is preferably 1.8% or less, particularly preferably 1.5% or less.
  • Ti is made 0.005% or more is to refine the prior austenite crystal grains after quenching, improve the strength and yield ratio, and improve the toughness and corrosion fatigue characteristics. By improving toughness, sag resistance can be improved.
  • the reason why Ti is made 0.10% or less is to prevent coarse inclusions (for example, Ti nitride) from precipitating and to suppress deterioration of corrosion fatigue characteristics.
  • the lower limit of the Ti amount is preferably 0.01% or more (particularly preferably 0.05% or more), and the upper limit of the Ti amount is preferably 0.080% or less, more preferably 0.07% or less. .
  • V is an element that effectively acts to further enhance the hardenability and increase the strength. In addition to enhancing toughness and improving sag resistance, it is an element that refines crystal grains to improve strength and proof stress ratio. In order to exert such an action, V is preferably contained in an amount of 0.05% or more, more preferably 0.08% or more, and further preferably 0.1% or more. However, when V is excessive, coarse carbonitrides are formed, and toughness and corrosion fatigue properties are deteriorated. Therefore, V is 0.25% or less, preferably 0.22% or less, more preferably 0.2% or less.
  • Nb is an element that contributes to improvement in sag resistance by increasing toughness, and is an element that refines crystal grains to improve strength and proof stress ratio.
  • the Nb amount is set to 0.005% or more.
  • the amount of Nb is preferably 0.008% or more, and more preferably 0.01% or more.
  • the Nb content is 0.05% or less.
  • the Nb amount is preferably 0.04% or less, more preferably 0.03% or less.
  • Ti, V and Nb may be added alone or in combination of two or more.
  • the contents of Ti, V, and Nb are Ti: 0.035 to 0.10%, Nb: 0.005 to 0.05%, and V: 0.05 to 0.25%, respectively. It is preferable to contain. Further, by containing Ti, V and Nb in such a range, the effect of crystal grain refinement can be effectively exhibited, and the crystal grain size after quenching can be set to 7.5 or more, Good low temperature toughness can be exhibited.
  • the grain size after quenching is more preferably 8.0 or more, and even more preferably 9.0 or more.
  • the low temperature toughness of the spring steel of the present invention is, for example, that Charpy absorbed energy at ⁇ 50 ° C. is 50 J / cm 2 or more, preferably 70 J / cm 2 or more, more preferably 80 J / cm 2 or more.
  • Cr When Cr is 0.05% or more, the steel matrix is strengthened by solid solution strengthening, and the hardenability is improved and the strength can be secured. Further, it is an element that contributes to the improvement of corrosion resistance by making the rust generated in the surface layer portion under the corrosive condition amorphous and dense.
  • Cr when Cr is 1.20% or less, the Ms point is lowered to prevent formation of a supercooled structure, and toughness and corrosion fatigue characteristics can be secured, and strength due to insufficient penetration of Cr carbide during quenching. And a decrease in hardness can be prevented.
  • Cr is preferably 0.1% or more and 1.10% or less, more preferably 0.5% or more and 1.05% or less.
  • the balance of the spring steel of the present invention is substantially iron.
  • steel contains unavoidable impurities brought in depending on the situation of materials such as iron raw materials (including scrap) and auxiliary materials, manufacturing equipment, and the like.
  • unavoidable impurities P is defined as 0.030% or less and S is defined as 0.02% or less. The reason for setting such a range is as follows.
  • P is set to 0.030% or less. The reason why P is set to 0.030% or less is to prevent segregation at the prior austenite grain boundaries and embrittle the grain boundaries, and to prevent deterioration of toughness and corrosion fatigue characteristics.
  • P is preferably 0.02% or less, more preferably 0.01% or less. The smaller the amount of P, the better. However, it is usually contained in an amount of about 0.001%.
  • S is set to 0.02% or less.
  • S is preferably 0.015% or less, particularly 0.01% or less.
  • P is preferably as small as P, but is usually contained in an amount of about 0.001%.
  • the total amount of P and S is preferably 0.015% or less, more preferably 0.010% or less.
  • the reason why the carbon equivalent Ceq 1 is 0.55 or less is that, when coiled spring steel is manufactured to produce a coil spring, the strength and corrosion fatigue characteristics of the spring are compatible even if the tempering treatment after quenching is omitted. Because. That is, the carbon equivalent Ceq 1 indicates the contribution of the alloy element that affects the hardness after quenching. By reducing this numerical value and omitting the tempering treatment after quenching, the core portion of the spring is obtained. Hardness can be secured and high strength can be achieved. In addition, by suppressing the carbon equivalent Ceq 1 to 0.55 or less, the dependence of the alloy elements can be reduced, and the stable supply ability can be improved.
  • the carbon equivalent Ceq 1 is preferably 0.53 or less, more preferably 0.50 or less.
  • the carbon equivalent Ceq 1 can be reduced in cost by designing the component so as to be as small as possible. However, in order to achieve both high strength and corrosion fatigue characteristics, it is necessary to add an alloy element to some extent. Therefore, the lower limit value of the carbon equivalent Ceq 1 is 0.30. In addition, in calculating the following formula (1), when there is an element that is not contained, the content of the element is assumed to be 0% by mass.
  • the spring steel of the present invention satisfies the above chemical composition and the carbon equivalent Ceq 1 , but contains Ni and Cu, or contains B and / or Mo with the aim of further improving the characteristics. It may be contained.
  • Ni and Cu When Ni and Cu are contained (that is, when Ni and Cu are used in combination), the Ni content is 0.05 to 2% and the Cu content is 0.05 to 0.50%.
  • the reason why Ni is set to 0.05% or more is to increase toughness, reduce defect sensitivity, and improve corrosion fatigue characteristics. Further, Ni has an effect of improving corrosion resistance by forming amorphous rust that is amorphous and dense, and also has an effect of improving the sag characteristic important as a spring characteristic.
  • Ni is preferably 0.15% or more and 2% or less, more preferably 0.18% or more and 1.5% or less, further preferably 0.20% or more and 1% or less, particularly 0.5%. It is as follows.
  • Cu is an element that is electrochemically noble than iron (noble) and therefore has the effect of densifying rust and improving corrosion resistance. Therefore, when Cu is contained, the amount of Cu is set to 0.05% or more. However, even if added excessively, the effect is saturated, and there is a possibility of causing embrittlement of the material due to hot rolling. Therefore, the upper limit of Cu content is 0.50% or less. Cu is preferably 0.1% or more and 0.4% or less, more preferably 0.15% or more (particularly 0.18% or more) and 0.3% or less.
  • B is an element that further enhances hardenability to increase grain boundary strength, enhance toughness and improve sag resistance, and further densify rust generated on the surface to improve corrosion resistance.
  • B is preferably contained in an amount of 0.0005% or more, more preferably 0.001% or more, and further preferably 0.0015% or more.
  • B is 0.005% or less, preferably 0.004% or less, more preferably 0.003% or less.
  • Mo is an element that increases toughness and contributes to improvement in sag resistance, and also ensures hardenability and increases the strength and toughness of steel.
  • the Mo amount is preferably 0.05% or more, more preferably 0.08% or more, and further preferably 0.10% or more.
  • the Mo content is preferably 0.60% or less, more preferably 0.50% or less, and still more preferably 0.35% or less.
  • B and Mo may be contained alone or in combination.
  • the spring steel according to the present invention is characterized in that the amount of each alloying element is strictly defined and the relationship between them is specified. If this spring steel is used, it is performed after coiling. A tempering treatment after quenching can be omitted, and a spring having both high strength with a tensile strength of 1900 MPa or more and good corrosion fatigue characteristics can be produced even when quenched. Moreover, low temperature toughness can be improved by controlling the content of elements (Ti, Nb and V) having a grain refinement action more strictly.
  • elements Ti, Nb and V
  • tempering means that the material is not heated to a temperature exceeding 350 ° C. after quenching.
  • the above setting may be performed cold or warm.
  • the temperature at the time of cold setting may be normal temperature, and the temperature at the time of cold setting may be about 200 to 250 ° C.
  • the conditions for shot peening and painting are not particularly limited, and conventional conditions can be adopted.
  • the spring thus obtained can achieve both high strength and good corrosion fatigue properties, and is also excellent in low temperature toughness.
  • the production conditions of the spring steel according to the present invention are not particularly limited, but in order to make the crystal grain size 7.5 or more which is a preferred embodiment of the present invention, for example, the heating temperature at the time of quenching is set to 925 ° C. or less, and the heating is performed. It is recommended that the time be 15 minutes or less.
  • the lower limit of the heating temperature and the heating time at the time of quenching is not particularly limited, the lower limit of the heating temperature is usually about 850 ° C., and the lower limit of the heating time is about 10 minutes.
  • Example 1 The steel of the chemical composition shown in Table 1 below (the balance is iron and inevitable impurities) was melted in a 150 kg vacuum melting furnace and held at 1200 ° C., then hot forged into a 155 mm square billet, This billet was hot-rolled to produce a spring steel (spring wire) having a diameter of 13.5 mm. The spring wire was subjected to a polishing rod process so that the diameter was 12.5 mm, and was then quenched after being cut to a length of 70 mm. Quenching was performed by heating at a temperature of 925 ° C. for 10 minutes and then placing in an oil bath at a temperature of 50 ° C. After quenching, a test piece having a width of 10 mm, a thickness of 1.5 mm and a length of 65 mm was cut out by machining.
  • Table 1 The steel of the chemical composition shown in Table 1 below (the balance is iron and inevitable impurities) was melted in a 150 kg vacuum melting furnace and held at 1200 ° C., then hot
  • Table 1 shows the results of calculating the amount of chemical components in the steel and the carbon equivalent (Ceq 1 ) calculated from the above formula (1).
  • the strength and corrosion fatigue properties of the test specimens were measured by simulating the setting performed cold or warm. That is, when simulating cold setting, the test piece was used for each test as it was, and when simulating warm setting, the test piece heated at 200 ° C. for 60 minutes was used for each test. Table 2 below shows which of the cold setting and the warm setting is simulated.
  • the corrosion fatigue characteristics were evaluated by conducting a hydrogen embrittlement cracking test.
  • a stress of 1400 MPa was applied to the above test piece by four-point bending, and this test piece was treated with sulfuric acid (0.5 mol / L) and potassium thiocyanate (KSCN; 0.01 mol / L).
  • the sample was immersed in a mixed aqueous solution, and a voltage of ⁇ 700 mV, which is lower than the SCE electrode, was applied using a potentiostat, and the time until cracking occurred (hereinafter referred to as hydrogen embrittlement crack life) was measured. did.
  • the measurement results of the hydrogen embrittlement cracking test are shown in Table 2 below. In the present invention, a case where the time until occurrence of cracking is 600 seconds or more is regarded as acceptable.
  • FIG. 1 shows the relationship between the carbon equivalent (Ceq 1 ) and the hydrogen embrittlement crack life (seconds).
  • the results of 1 to 15, 31, and 33 are indicated by ⁇ and No.
  • the results of 16 to 29, 32 are indicated by ⁇ and No.
  • the result of 30 (with tempering) is indicated by ⁇ .
  • No. 30 is an example of tempering after quenching.
  • the core hardness can be secured, the strength is high, the hydrogen embrittlement crack life is good, and the corrosion fatigue characteristics can be improved.
  • tempering is performed after quenching, CO 2 emissions cannot be reduced.
  • No. The component composition of No. 29 is the above No. This is an example similar to 30, but without tempering after quenching. In this example, the tempering process is omitted, so that the CO 2 emission can be reduced. However, since the carbon equivalent exceeds 0.55 and the alloy element amount is large, the tempering is omitted. The partial hardness becomes too hard, the toughness is lowered, the hydrogen embrittlement crack life is shortened, and the corrosion fatigue characteristics are deteriorated.
  • No. Nos. 16 to 28 and 32 are examples that do not satisfy the requirements defined in the present invention, and cannot achieve both high strength and good corrosion fatigue characteristics. That is, the carbon equivalent (Ceq 1 ) of the spring steel exceeds the range specified in the present invention, and the tempering after quenching is omitted, so that the CO 2 emission can be reduced, but the core hardness is hard. As a result, the toughness is lowered, the hydrogen embrittlement crack life is shortened, and the corrosion fatigue characteristics are deteriorated.
  • No. Nos. 1 to 15 and 33 are examples that satisfy the requirements defined in the present invention, and both high strength and good corrosion fatigue characteristics can be achieved. That is, after suppressing the carbon equivalent (Ceq 1 ) to 0.55 or less, and tempering after quenching is omitted, CO 2 emission can be reduced, and the core hardness can be appropriately secured. High strength can be achieved. In addition, the hydrogen embrittlement crack life is long, and the corrosion fatigue characteristics can be improved. Moreover, since the carbon equivalent (Ceq 1 ) of the spring steel is suppressed to 0.55 or less, the dependence of the alloy elements can be reduced, and stable supply can be realized. Therefore, when the spring steel of the present invention is used, the above No. 1 simulating the “UHS1900”. It can be seen that a spring exhibiting characteristics comparable to or higher than 30 can be provided.
  • Example 2 Steel materials having the chemical composition shown in Table 3 (the balance being iron and inevitable impurities) were melted in a 150 kg vacuum melting furnace, then cast by the ingot-making method or continuous casting method, and then 155 mm square by split rolling.
  • the billet was prepared, further hot-rolled, and processed into a wire having a diameter of 13.5 mm to obtain a test material.
  • These specimens were heated at a temperature of 925 ° C. for 10 minutes and then quenched in an oil bath at 50 ° C. No. Only 2-24 was tempered at 400 ° C. for 1 hour after the quenching.
  • No. in Table 4 2-1. No. 2-14 satisfies the requirements of the present invention, and in particular, the Ti, Nb, and V contents are appropriately adjusted, so that a steel having high strength and excellent low-temperature toughness could be realized.
  • No. 2-15 ⁇ No. No. 2-24 did not satisfy at least one of the requirements of the present invention, and thus toughness was insufficient.
  • No. 2-15 ⁇ No. No. 2-19 was an example in which the amount of C was excessive, and the low temperature toughness decreased due to the excessive increase in strength.
  • No. 2-23 and no. No. 2-24 is a steel grade corresponding to standard steel 9254.
  • No. 2-24 has been tempered after quenching.
  • No. No. 2-23 had a large amount of C and an excessively high strength, and did not contain any of Ti, Nb and V, so that the low temperature toughness decreased.
  • FIG. FIG. 2 is a graph showing the relationship between strength and low temperature toughness (Charpy absorbed energy at ⁇ 50 ° C.) for 2-1 to 2-24.
  • the results of 2-1 to 2-14 and 2-25 are indicated by ⁇ and No. 2-15 ⁇ No.
  • the results of Nos. 2-23 and 2-26 are indicated by ⁇ ,
  • the result of 2-24 was indicated by ⁇ .
  • all the steels satisfying the requirements of the present invention (indicated by ⁇ in FIG. 2) have a Charpy absorbed energy of 50 J / cm 2 or more and steels that do not satisfy any of the requirements of the present invention ( In FIG. 2, it can be seen that high toughness is achieved when compared at the same strength as indicated by ⁇ and ⁇ .

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Manufacturing & Machinery (AREA)
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Abstract

L'invention concerne un acier à ressorts qui contient de 0,15 à 0,40% de carbone, de 1 à 3,5% de silicium, de 0,20 à 2,0% de manganèse, de 0,05 à 1,20% de chrome, au plus 0,030% de phosphore, au plus 0,02% de soufre et au moins l'un des éléments suivants : de 0,005 à 0,10% de titane, de 0,005 à 0,05% de niobium, et au plus 0,25% de vanadium. Le reste dudit acier à ressorts comprend du fer et les inévitables impuretés. L'équivalent carbone (Ceq1) de l'acier à ressorts proposé, tel que calculé par la formule (1), est au plus de 0,55. (1) Ceq1 = [C] + 0,108×[Si] − 0,067×[Mn] + 0,024×[Cr] − 0,05×[Ni] + 0,074×[V] (Dans la formule (1), chaque symbole entre crochets représente la teneur (% en masse) de l'élément correspondant.)
PCT/JP2010/073003 2009-12-22 2010-12-21 Acier à ressorts à haute résistance WO2011078165A1 (fr)

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ES10839395T ES2709515T3 (es) 2009-12-22 2010-12-21 Acero para muelles de alta resistencia
US13/511,541 US20120285585A1 (en) 2009-12-22 2010-12-21 High-strength spring steel
EP10839395.0A EP2518175B1 (fr) 2009-12-22 2010-12-21 Acier à ressorts à haute résistance
BR112012014178A BR112012014178A2 (pt) 2009-12-22 2010-12-21 aço para mola com alta resistência
CN201080039360.2A CN102482743B (zh) 2009-12-22 2010-12-21 高强度弹簧用钢
US15/286,065 US20170022580A1 (en) 2009-12-22 2016-10-05 High-strength spring steel

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JP2009291143 2009-12-22

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US15/286,065 Continuation US20170022580A1 (en) 2009-12-22 2016-10-05 High-strength spring steel

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2811198A4 (fr) * 2012-01-31 2016-01-06 Nhk Spring Co Ltd Ressort de forme annulaire et procédé de fabrication de celui-ci

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014198874A (ja) 2013-03-29 2014-10-23 株式会社神戸製鋼所 耐食性と磁気特性に優れた鋼材およびその製造方法
JP6477007B2 (ja) * 2015-02-26 2019-03-06 愛知製鋼株式会社 板ばね及びその製造方法
CN105088081B (zh) * 2015-08-28 2018-03-13 浙江美力汽车弹簧有限公司 稳定杆的制造工艺
CN105112774B (zh) * 2015-08-28 2017-12-01 浙江美力科技股份有限公司 高强韧性低中碳微合金风冷硬化弹簧钢及其成形和热处理工艺
KR101795277B1 (ko) * 2016-06-21 2017-11-08 현대자동차주식회사 내식성이 우수한 고강도 스프링강
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CN106011634A (zh) * 2016-07-26 2016-10-12 路望培 一种弹簧机械材料及其制备方法
CN106636896A (zh) * 2016-12-05 2017-05-10 武汉钢铁股份有限公司 一种高淬透性热轧刀板钢
CN107354388B (zh) * 2017-07-25 2019-03-01 西华大学 一种高强高韧贝氏体弹簧钢及其制造方法
JP2020076154A (ja) * 2020-01-07 2020-05-21 日本発條株式会社 懸架装置用ばねの製造方法
CN114134411B (zh) * 2021-10-12 2022-07-29 江阴兴澄特种钢铁有限公司 一种耐低温高强度滚珠丝杠用球化退火钢及其制造方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11323495A (ja) * 1998-05-13 1999-11-26 Kobe Steel Ltd 非調質ばね用圧延線状鋼または棒状鋼
JP2001049337A (ja) * 1999-08-05 2001-02-20 Kobe Steel Ltd 疲労強度に優れた高強度ばねの製造方法
JP3246733B2 (ja) 1999-10-29 2002-01-15 三菱製鋼室蘭特殊鋼株式会社 高強度ばね用鋼
JP2004263247A (ja) * 2003-02-28 2004-09-24 Daido Steel Co Ltd 冷間成形ばね用鋼
JP3577411B2 (ja) 1997-05-12 2004-10-13 新日本製鐵株式会社 高靭性ばね鋼
JP2009046764A (ja) * 2007-07-20 2009-03-05 Kobe Steel Ltd 腐食疲労特性に優れたばね用鋼
JP4406341B2 (ja) 2004-09-22 2010-01-27 Ｊｆｅ条鋼株式会社 靭性に優れた高強度スタビライザの製造方法

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61276952A (ja) * 1985-06-01 1986-12-06 Nissan Motor Co Ltd 強靭鋼
JPS62267420A (ja) * 1986-05-13 1987-11-20 Kobe Steel Ltd 耐遅れ破壊性の優れた高張力、高靭性線材の製造法
JPH0830246B2 (ja) * 1987-03-05 1996-03-27 大同特殊鋼株式会社 高強度ばね用鋼
JPH0892696A (ja) * 1994-09-26 1996-04-09 Nippon Steel Corp 高強度ベイナイト系レール
US5776267A (en) * 1995-10-27 1998-07-07 Kabushiki Kaisha Kobe Seiko Sho Spring steel with excellent resistance to hydrogen embrittlement and fatigue
JP3966493B2 (ja) * 1999-05-26 2007-08-29 新日本製鐵株式会社 冷間鍛造用線材及びその製造方法
JP3968011B2 (ja) * 2002-05-27 2007-08-29 新日本製鐵株式会社 低温靱性および溶接熱影響部靱性に優れた高強度鋼とその製造方法および高強度鋼管の製造方法
CA2531615A1 (fr) * 2004-12-28 2006-06-28 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Tole mince d'acier a haute resistance possedant une resistance elevee a la fragilisation par l'hydrogene
JP4476863B2 (ja) * 2005-04-11 2010-06-09 株式会社神戸製鋼所 耐食性に優れた冷間成形ばね用鋼線
JP5064060B2 (ja) * 2007-02-22 2012-10-31 新日本製鐵株式会社 高強度ばね用鋼線及び高強度ばね並びにそれらの製造方法
JP5306845B2 (ja) * 2009-02-12 2013-10-02 Ｊｆｅ条鋼株式会社 耐食性と低温靭性に優れた車両用高強度スタビライザ用鋼及びその製造方法とスタビライザ
JP5324311B2 (ja) * 2009-05-15 2013-10-23 株式会社神戸製鋼所 高強度ばね用中空シームレスパイプ

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3577411B2 (ja) 1997-05-12 2004-10-13 新日本製鐵株式会社 高靭性ばね鋼
JPH11323495A (ja) * 1998-05-13 1999-11-26 Kobe Steel Ltd 非調質ばね用圧延線状鋼または棒状鋼
JP2001049337A (ja) * 1999-08-05 2001-02-20 Kobe Steel Ltd 疲労強度に優れた高強度ばねの製造方法
JP3246733B2 (ja) 1999-10-29 2002-01-15 三菱製鋼室蘭特殊鋼株式会社 高強度ばね用鋼
JP2004263247A (ja) * 2003-02-28 2004-09-24 Daido Steel Co Ltd 冷間成形ばね用鋼
JP4406341B2 (ja) 2004-09-22 2010-01-27 Ｊｆｅ条鋼株式会社 靭性に優れた高強度スタビライザの製造方法
JP2009046764A (ja) * 2007-07-20 2009-03-05 Kobe Steel Ltd 腐食疲労特性に優れたばね用鋼

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2811198A4 (fr) * 2012-01-31 2016-01-06 Nhk Spring Co Ltd Ressort de forme annulaire et procédé de fabrication de celui-ci

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EP2518175A1 (fr) 2012-10-31
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BR112012014178A2 (pt) 2016-07-05
EP2518175A4 (fr) 2015-12-02
CN102482743B (zh) 2014-12-24
US20170022580A1 (en) 2017-01-26
US20120285585A1 (en) 2012-11-15
ES2709515T3 (es) 2019-04-16
JP2011149089A (ja) 2011-08-04
KR20120084810A (ko) 2012-07-30
JP6027302B2 (ja) 2016-11-16
JP2015214754A (ja) 2015-12-03

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