WO2013077182A1 - 熱間鍛造用圧延棒鋼 - Google Patents
熱間鍛造用圧延棒鋼 Download PDFInfo
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- WO2013077182A1 WO2013077182A1 PCT/JP2012/078789 JP2012078789W WO2013077182A1 WO 2013077182 A1 WO2013077182 A1 WO 2013077182A1 JP 2012078789 W JP2012078789 W JP 2012078789W WO 2013077182 A1 WO2013077182 A1 WO 2013077182A1
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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
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
- B21J1/003—Selecting material
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
- B21J1/06—Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/002—Hybrid process, e.g. forging following casting
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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
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
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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
- 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
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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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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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
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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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
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
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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
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
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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
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
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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
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium 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
- C22C38/42—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
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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
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/005—Ferrite
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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
- C21D2211/00—Microstructure comprising significant phases
- C21D2211/009—Pearlite
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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
- C21D9/0075—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rods of limited length
Definitions
- the present invention relates to a rolled steel bar for hot forging. More specifically, the present invention relates to a rolled steel bar for hot forging that can be suitably used as a material for high-strength non-tempered hot forged parts such as automobiles and industrial machines.
- hot forging is applied to steel bars manufactured by hot rolling (hereinafter referred to as “rolled steel bars”).
- Hot forging parts that are molded without any tempering treatment hereinafter referred to as “hot forging”
- the application of “parts called non-tempered hot forged parts”) is the mainstream.
- hot forged parts that are formed by being pressed substantially in the vertical direction of the axis of the rolled steel bar, that is, in the direction perpendicular to the rolling direction, with little reduction in the axial direction of the rolled steel bar.
- hot forged parts formed by pressing in such a direction distribution of inclusions and / or precipitates formed by hot rolling (that is, inclusions and / or precipitates stretched in the axial direction)
- the distribution state in the rolled steel bar is inherited even after hot forging.
- the fatigue strength against the stress in the direction perpendicular to the axis of the hot forged part (hereinafter, the fatigue strength against the stress in the direction perpendicular to the axis of the hot forged part is referred to as “lateral fatigue strength”) tends to be low. .
- the fatigue strength of the transverse eye can also be increased.
- increasing the tensile strength of a non-tempered hot forged part manufactured without performing a tempering treatment leads to a reduction in tool life in a cutting process performed after hot forging. For this reason, there arises a problem that the cutting cost increases and the cutting time becomes long.
- Patent Document 1 and Patent Document 2 describe the following “high strength high toughness non-heat treated steel for hot forging and manufacturing method thereof” and “non-heat treated steel for high strength hot forging”. Is disclosed.
- Patent Document 1 In mass%, Si: 2% or less (not including 0%), S: 0.10% or less (not including 0%), N: 0.02% or less (not including 0%), O: 0 In steel containing 0.010% or less (excluding 0%) and inevitable impurities, C: 0.10 to 0.6%, Mn: 0.3 to 2.5%, Cr: 0.05 to 2.5%, V: 0.03 to 0.5%, Al: 0.060% or less (excluding 0%), Ti: 0.005 to 0.03%, and if necessary Furthermore, Pb: 0.3% or less (not including 0%), Ca: 0.01% or less (not including 0%), Te: 0.3% or less (not including 0%), Bi: 0 .3% or less (excluding 0%), Zr: 0.1% or less (not including 0%), Hf: 0.1% or less (not including 0%), Y: 0.1% or less ( 0% 1), rare earth element: 0.1% or less (not including 0%), Mg: 0.1% or less (not including 0%), and at least one
- a non-tempered hot forged part can be provided with a tensile strength of 90 kgf / mm 2 (882.6 MPa) or more.
- a Ti acid having an average crystal grain size of 0.1 to 5 ⁇ m is simply used.
- -Rolling steel bars can be formed only by containing nitride, MnS, and inclusions that are composite compounds mainly composed of Ti acid / nitride and MnS at 1 ⁇ 10 2 to 1 ⁇ 10 6 pieces / mm 2 .
- the fatigue strength of the side is reduced by Ti nitrides arranged in the axial direction of the hot forged parts.
- a non-tempered hot forged part can be provided with a tensile strength of 900 MPa or more.
- the non-tempered hot forged part is made of a mixed structure of ferrite and pearlite that avoids the formation of bainite (hereinafter referred to as “ferrite / pearlite”), and therefore has excellent machinability.
- the steel specifically disclosed in Patent Document 2 contains at least 0.033% S.
- S the number of S is contained in the steel, when the rolled steel bar is used by being formed by hot forging while being rolled down in the vertical direction of the shaft, There is a possibility that the fatigue strength of the lateral eye may be reduced by the coarse MnS arranged.
- the present invention has been made in view of the above situation, and obtains a high strength non-tempered hot forged part having a tensile strength of 900 MPa or more and a durability ratio (fatigue strength / tensile strength) of 0.47 or more.
- An object of the present invention is to provide a rolled steel bar for hot forging that can be used.
- the durability ratio of the transverse is a value obtained by dividing the fatigue strength against the stress in the vertical direction of the hot forged part by the tensile strength in the vertical direction of the hot forged part.
- the present inventors conducted various studies in order to solve the above-described problems. As a result, the following findings (a) to (f) were obtained.
- (C) It is effective to contain a precipitation strengthening element in order to obtain high transverse fatigue strength in a hot forged part that is formed by being rolled in the direction perpendicular to the axis of the rolled steel bar. However, it is not preferable to add Ti that easily forms coarse nitrides during solidification.
- V does not form coarse nitrides during solidification like Ti. Therefore, the N content can also be increased, whereby V carbide, nitride, or carbonitride can be precipitated in the cooling process during hot forging, and high lateral fatigue strength can be imparted.
- the present invention has been completed based on the above findings, and the gist thereof is the rolled steel bar for hot forging shown below.
- Y2 C + (1/10) Si + (1/5) Mn + (5/22) Cr + 1.65V- (5/7) S + (1/5) Cu + (1/5) Ni + (1/4) Mo. ⁇ ⁇ 2>
- C, Si, Mn, Cr, V, S, Cu, Ni, and Mo in the above formula ⁇ 2> represent the content in mass% of each element.
- Impurity refers to what is mixed from ore, scrap, or the production environment as raw materials when industrially producing steel materials.
- a high-strength non-tempered hot forged part having a tensile strength of 900 MPa or more and a durability ratio of 0.47 or more can be obtained.
- C 0.27 to 0.37%
- C is an element that strengthens steel, and must be contained by 0.27% or more.
- the C content is set to 0.27 to 0.37%.
- the C content is preferably 0.29% or more, and more preferably 0.35% or less.
- Si 0.30 to 0.75%
- Si is a deoxidizing element and is an element necessary for strengthening ferrite by solid solution strengthening and increasing the tensile strength after hot forging. In order to ensure such an effect, it is necessary to contain 0.30% or more of Si. On the other hand, when the Si content exceeds 0.75%, not only the effect is saturated, but also surface decarburization of the rolled steel bar becomes remarkable. Therefore, the Si content is set to 0.30 to 0.75%.
- the Si content is preferably 0.35% or more, and preferably 0.70% or less.
- Mn 1.00 to 1.45%
- Mn is an element necessary for strengthening ferrite and pearlite by solid solution strengthening and increasing the tensile strength after hot forging, and must be contained by 1.00% or more.
- the Mn content is set to 1.00 to 1.45%.
- the Mn content is preferably 1.10% or more, and preferably 1.40% or less.
- S 0.008% or more and less than 0.030%
- S is an important element in the present invention. Since S combines with Mn to form MnS and increases the number of ferrite nuclei in the austenite grains after hot forging, the formation of bainite can be suppressed. Furthermore, machinability is also improved by MnS. Therefore, 0.008% or more of S must be contained.
- the S content needs to be strictly controlled and is set to be 0.008% or more and less than 0.030%.
- the S content is desirably 0.010% or more, and desirably 0.027% or less.
- Cr 0.05-0.30% Cr, like Mn, is an element that strengthens ferrite and pearlite by solid solution strengthening and increases the tensile strength after hot forging, and must be contained by 0.05% or more.
- the Cr content is set to 0.05 to 0.30%.
- the Cr content is preferably 0.08% or more, and preferably 0.20% or less. More preferably, the Cr content is less than 0.20%.
- Al 0.005 to 0.050%
- Al not only has a deoxidizing action, but also binds to N to form AlN, and by its pinning effect, it suppresses the growth of austenite grains during hot forging and suppresses the formation of bainite. For this reason, Al must be contained 0.005% or more.
- the Al content is set to 0.005 to 0.050%.
- the Al content is preferably 0.010% or more.
- V 0.200-0.320%
- V combines with C and N to form carbides, nitrides, or carbonitrides, and has the effect of effectively increasing the durability ratio of the hot-forged parts. For this reason, 0.200% or more of V is contained. On the other hand, when the content of V exceeds 0.320%, the effect is saturated and the cost is increased. Therefore, the V content is set to 0.200 to 0.320%.
- the V content is preferably 0.220% or more, and more preferably 0.300% or less.
- N 0.0080 to 0.0200%
- N is an important element in the present invention.
- N combines with V to form a nitride or carbonitride to effectively increase the durability ratio of the cross-section of the hot forged part, and also combines with Al to form AlN.
- the pinning effect suppresses the growth of austenite grains during hot forging and suppresses the formation of bainite. For this reason, it is necessary to contain 0.0080% or more of N.
- the N content is set to 0.0080 to 0.0200%.
- the N content is preferably 0.0090% or more, and preferably 0.0150% or less.
- the rolled steel bar for hot forging of the present invention is composed of the above-described elements C to N, the balance being Fe and impurities, and P, Ti and O in the impurities are P: 0.030% or less, Ti : 0.0040% or less and O: 0.0020% or less, and Y1 represented by the above formula ⁇ 1> has a chemical composition of 1.05 to 1.18.
- impurities refer to those mixed from ore, scrap, or the production environment as raw materials when industrially producing steel materials.
- P 0.030% or less
- P is an element contained as an impurity in steel.
- the content of P in the impurities is set to 0.030% or less.
- the content of P in the impurities is preferably 0.025% or less.
- the content of P contained as an impurity is desirably as small as possible within a range that does not increase the cost in the steelmaking process.
- Ti 0.0040% or less
- Ti is an element whose content must be limited.
- Ti cannot avoid mixing from ores and scraps.
- the amount of mixed Ti becomes high although it is an impurity.
- the content of Ti in the impurities is set to 0.0040% or less.
- the content of Ti in the impurities is preferably 0.0035% or less, and more preferably less than 0.0030%.
- O oxygen
- oxygen is an impurity element that exists mainly in the steel as oxide inclusions and causes a reduction in the fatigue strength of the transverse.
- the content of O in the impurities is set to 0.0020% or less. Note that the content of O in the impurities is preferably 0.0015% or less.
- the rolled steel bar for hot forging of the present invention may contain one or more elements selected from Cu, Ni, and Mo as needed, instead of a part of the above-mentioned Fe.
- Y2 represented by the above formula ⁇ 2> is 1.05 to 1.18.
- Cu 0.30% or less
- Cu is an element that strengthens ferrite and pearlite by solid solution strengthening. For this reason, you may contain Cu. However, if the Cu content exceeds 0.30%, not only the effect is saturated, but the hardenability becomes high, and bainite is generated after hot forging, which may cause a decrease in the fatigue strength of the transverse eye. . Therefore, an upper limit is set for the amount of Cu in the case of inclusion, and is set to 0.30% or less. When Cu is contained, the amount of Cu is preferably 0.20% or less.
- the amount of Cu is preferably 0.03% or more, and more preferably 0.05% or more.
- Ni 0.30% or less
- Ni is an element that strengthens ferrite and pearlite by solid solution strengthening. For this reason, Ni may be contained. However, if the Ni content exceeds 0.30%, not only the effect is saturated, but the hardenability becomes high, and bainite is generated after hot forging, which may cause a decrease in fatigue strength of the side. . Therefore, an upper limit is set for the amount of Ni in the case of inclusion, and it is set to 0.30% or less. When Ni is contained, the amount of Ni is preferably 0.20% or less.
- the amount of Ni is preferably 0.03% or more, and more preferably 0.05% or more.
- Mo 0.10% or less
- Mo is an element that strengthens ferrite and pearlite by solid solution strengthening. For this reason, you may contain Mo. However, if the Mo content exceeds 0.10%, bainite may be generated after hot forging, leading to a decrease in the fatigue strength of the cross. Therefore, an upper limit is set for the amount of Mo in the case of inclusion, and the content is made 0.10% or less. When Mo is contained, the amount of Mo is preferably 0.08% or less.
- the amount of Mo when contained is preferably 0.03% or more.
- the above Cu, Ni and Mo can be contained alone or in combination of two or more.
- the total content of Cu, Ni and Mo is preferably 0.30% or less.
- Y1 or Y2 1.05 to 1.18
- the rolled steel bar for hot forging which is the material of the non-tempered hot forged part
- Y1 C + (1/10) Si + (1/5) Mn + (5/22) Cr + 1.65V ⁇ (5/7] represented by the above formula ⁇ 1> )
- Y2 C + (1/10) Si + (1/5) Mn + (5/22) Cr + 1 represented by the above formula ⁇ 2> .65V- (5/7)
- Y1 or Y2 exceeds 1.18, the hardness after hot forging becomes high, which may lead to a decrease in machinability. Furthermore, hardenability becomes high, bainite is generated after hot forging, and the endurance ratio may decrease. On the other hand, if Y1 or Y2 is less than 1.05, it is not possible to ensure a tensile strength of 900 MPa or more in the non-tempered hot forged part made of the hot forged rolled steel bar.
- Y1 or Y2 is preferably 1.08 or more, and preferably 1.16 or less.
- the rolled steel bar for hot forging of the present invention is a steel of 180 mm ⁇ 180 mm obtained by heating a cast slab having the chemical composition defined in the present invention, for example, at 1200-1300 ° C. for 120-180 minutes and then rolling it in pieces. It can be obtained by producing a piece, and then heating the steel piece at 1150 to 1250 ° C. for 90 to 150 minutes and rolling it to a predetermined size, for example, a diameter of 40 mm, in a temperature range of 1100 to 1000 ° C. .
- the rolled steel bar for hot forging of the present invention having a predetermined size, for example, a diameter of 40 mm, is cut into, for example, a length of 100 mm, heated to 1200 to 1250 ° C. with a high-frequency heating device, and then 1150 to 1100.
- a hot forging machine in the temperature range of °C, press forging in the direction perpendicular to the axis of the rolled steel bar to a thickness of 18 mm, and cooling the temperature range of 800-550 °C at a cooling rate of 30-50 °C / min
- a non-tempered hot forged part having a tensile strength of 900 MPa or more and a durability ratio of 0.47 or more can be easily obtained.
- the “heating temperature” of the above slab and steel slab means the temperature in the furnace when the slab and steel slab are heated.
- Bar steel rolling temperature refers to the surface temperature of the material to be rolled.
- the “heating temperature” of a steel bar using a high-frequency heating device means the surface temperature of the steel bar.
- the press forging temperature using a hot forging machine and the temperature for cooling at a cooling rate of 30 to 50 ° C./min after forging also refer to the surface temperature of the material to be forged.
- the “cooling rate” in the temperature range of 800 to 550 ° C. after forging is a value obtained by dividing 250 ° C. as a temperature difference by the time required for the surface temperature of the forged material to decrease from 800 ° C. to 550 ° C. Point to.
- a slab having a cross section of 300 mm ⁇ 400 mm made of steel A to U having the chemical composition shown in Table 1 was heated at 1250 ° C. for 120 minutes, and then subjected to ingot rolling to produce a 180 mm ⁇ 180 mm steel slab. Thereafter, the steel slab was heated at 1200 ° C. for 90 minutes and hot-rolled in a temperature range of 1100 to 1000 ° C. to produce a steel bar having a diameter of 40 mm.
- Steels A to J in Table 1 are steels whose chemical compositions are within the range defined by the present invention.
- steels K to U are steels whose chemical compositions deviate from the conditions defined in the present invention.
- a forged product having a thickness of 18 mm was produced by hot forging using each steel bar having a diameter of 40 mm as a raw material.
- each steel bar having a diameter of 40 mm was cut into a length of 110 mm.
- a steel bar having a diameter of 40 mm and a length of 110 mm was heated to 1250 ° C. with a high-frequency heating device, and then hot forging was performed by pressing at 1150 to 1100 ° C. in the direction perpendicular to the axis of the bar steel to a thickness of 18 mm
- the forged product was finished, allowed to cool in the air, and cooled to room temperature.
- the cooling rate in the temperature range of 800 to 550 ° C. was 30 ° C./min.
- microstructure, tensile properties and fatigue properties of the above forged products were investigated by the methods ⁇ 1> to ⁇ 3> below.
- the number of tests was set to 8, and a rotating bending fatigue test was performed under the conditions that the stress ratio was ⁇ 1 at room temperature and in the atmosphere.
- the minimum value of the stress amplitude that was durable when the number of repetitions was 1.0 ⁇ 10 7 or more was defined as fatigue strength. Further, the fatigue strength was divided by the tensile strength to determine the endurance ratio of the transverse eye.
- the target for the endurance ratio of the forged product was 0.47 or more.
- Table 2 summarizes the above test results. “ ⁇ ” mark in the “Evaluation” column of Table 2 indicates that the tensile strength and the endurance ratio of the forged product both satisfy the above-mentioned target, and “ ⁇ ” mark indicates that at least one characteristic is the target. Indicates that it has not reached.
- test numbers 11 to 21 of comparative examples that do not satisfy the chemical composition defined in the present invention either of the tensile strength of the forged product or the durability ratio of the transverse does not reach the target.
- Test No. 11 has a V content of 0.177% in steel K used, which is below the range specified in the present invention. For this reason, the endurance ratio of the forged product is as low as 0.44.
- Test No. 12 is that the content of each element of the steel L used satisfies the conditions specified in the present invention, but Y1 is as high as 1.24, which is outside the range specified in the present invention. For this reason, in addition to ferrite and pearlite, bainite is recognized in the microstructure of the forged product, and the durability ratio of the lateral eye is as low as 0.41.
- Test No. 13 has a Ni content of 0.35% in the steel M used, which exceeds the range specified in the present invention. For this reason, in addition to ferrite and pearlite, bainite is recognized in the microstructure of the forged product, and the durability ratio of the lateral eye is as low as 0.40.
- Test No. 14 has a Ti content of the steel N used of 0.0098%, which exceeds the range specified in the present invention. For this reason, the endurance ratio of the forged product is as low as 0.44.
- Test No. 15 has a Mn content of the steel O used of 1.53%, which exceeds the range specified in the present invention. For this reason, in addition to ferrite and pearlite, bainite is recognized in the microstructure of the forged product, and the durability ratio of the lateral eye is as low as 0.41.
- Test No. 16 shows that the content of each element of the steel P used satisfies the conditions specified in the present invention, but Y2 is as high as 1.23, which is outside the range specified in the present invention. For this reason, in addition to ferrite and pearlite, bainite is recognized in the microstructure of the forged product, and the durability ratio of the lateral eye is as low as 0.41.
- Test No. 17 is that the content of each element of steel Q used satisfies the conditions specified in the present invention, but Y1 is as low as 0.96, which is outside the range specified in the present invention. For this reason, the tensile strength of a forged product is as low as 868 MPa.
- Test No. 18 has an S content of 0.043% in the steel R used, which exceeds the range defined in the present invention. For this reason, the endurance ratio of the forged product is as low as 0.42.
- Test No. 19 shows that the content of each element of the steel S used satisfies the conditions specified in the present invention, but Y2 is as low as 0.99, which is outside the range specified in the present invention. For this reason, the tensile strength of a forged product is as low as 874 MPa.
- Test No. 20 has an O content of the steel T used of 0.0031%, which exceeds the range specified in the present invention. For this reason, the endurance ratio of the forged product is as low as 0.42.
- Test No. 21 has a C content of 0.45% in the steel U used, which exceeds the range specified in the present invention. For this reason, the endurance ratio of the forged product is as low as 0.45.
- a high-strength non-tempered hot forged part having a tensile strength of 900 MPa or more and a durability ratio of 0.47 or more can be obtained.
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Abstract
Description
質量%で、Si:2%以下(0%を含まない)、S:0.10%以下(0%を含まない)、N:0.02%以下(0%を含まない)、O:0.010%以下(0%を含まない)および不可避的不純物を含む鋼において、さらに、C:0.10~0.6%、Mn:0.3~2.5%、Cr:0.05~2.5%、V:0.03~0.5%、Al:0.060%以下(0%を含まない)、Ti:0.005~0.03%を含有するとともに、必要に応じてさらに、Pb:0.3%以下(0%を含まない)、Ca:0.01%以下(0%を含まない)、Te:0.3%以下(0%を含まない)、Bi:0.3%以下(0%を含まない)、Zr:0.1%以下(0%を含まない)、Hf:0.1%以下(0%を含まない)、Y:0.1%以下(0%を含まない)、希土類元素:0.1%以下(0%を含まない)、Mg:0.1%以下(0%を含まない)のうちから選ばれる1種以上を含有し、残部がFeおよび不可避的不純物元素からなるとともに、平均結晶粒径が0.1~5μmである介在物を1×102~1×106個/mm2含有し、
上記介在物がTi酸・窒化物、MnS、および該Ti酸・窒化物とMnSを主体とする複合化合物である「熱間鍛造用高強度高靱性非調質鋼」およびその製造方法が開示されている。
質量%で、C:0.25~0.50%、Si:0.40~2.00%、Mn:0.50~2.50%、Cr:0.10~1.00%、S:0.03~0.10%、V:0.05~0.30%、N:0.0050~0.0200%、さらにAl:0.005~0.050%とTi:0.002~0.050%の1種または2種を含み、必要に応じてさらに、Ca:0.0004~0.0050%を含有し、残部がFeおよび不可避的不純物からなり、
Ceq.(%)=%C+(%Si)/20+(%Mn)/5+(%Cr)/9+1.54(%V)
の式で表される炭素当量Ceq.(%)が0.83~1.23%、
Bt=31.2-100(%C)-6.7(%Si)+9.0(%Mn)+4.9(%Cr)-81(%V)
の式で表されるベイナイト変態指数Btが0以下、
である高強度熱間鍛造用非調質鋼が開示されている。
残部がFeおよび不純物とからなり、
不純物中のP、TiおよびOがそれぞれ、質量%で、P:0.030%以下、Ti:0.0040%以下およびO:0.0020%以下であり、
かつ、下記の<1>式で表されるY1が1.05~1.18の化学組成であることを特徴とする、熱間鍛造用圧延棒鋼。
Y1=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S・・・<1>
ただし、上記<1>式におけるC、Si、Mn、Cr、VおよびSは、それぞれの元素の質量%での含有量を表す。
Cu:0.30%以下、Ni:0.30%以下およびMo:0.10%以下から選択される1種以上と、
残部がFeおよび不純物とからなり、
不純物中のP、TiおよびOがそれぞれ、質量%で、P:0.030%以下、Ti:0.0040%以下およびO:0.0020%以下であり、
かつ、下記の<2>式で表されるY2が1.05~1.18の化学組成であることを特徴とする、熱間鍛造用圧延棒鋼。
Y2=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S+(1/5)Cu+(1/5)Ni+(1/4)Mo・・・<2>
ただし、上記<2>式におけるC、Si、Mn、Cr、V、S、Cu、NiおよびMoは、それぞれの元素の質量%での含有量を表す。
Cは、鋼を強化する元素であり、0.27%以上含有させなくてはならない。一方、Cの含有量が0.37%を超えると、熱間鍛造後の引張強度は高くなるものの、横目の耐久比の低下を招いてしまう場合がある。したがって、Cの含有量を0.27~0.37%とした。Cの含有量は0.29%以上とすることが好ましく、0.35%以下とすることが好ましい。
Siは、脱酸元素であるとともに、固溶強化によってフェライトを強化し、熱間鍛造後の引張強度を高めるのに必要な元素である。こうした効果を確保するには、Siを0.30%以上含有させる必要がある。一方、Siの含有量が0.75%を超えると、その効果が飽和するばかりか、圧延棒鋼の表面脱炭が著しくなる。したがって、Siの含有量を0.30~0.75%とした。Siの含有量は0.35%以上とすることが好ましく、0.70%以下とすることが好ましい。
Mnは、固溶強化によってフェライトおよびパーライトを強化し、熱間鍛造後の引張強度を高めるのに必要な元素であり、1.00%以上含有させなくてはならない。一方、Mnの含有量が1.45%を超えると、その効果が飽和するばかりか、焼入れ性が高くなり、熱間鍛造後にベイナイトが生成して、横目の疲労強度の低下を招く場合がある。したがって、Mnの含有量を1.00~1.45%とした。Mnの含有量は1.10%以上とすることが好ましく、1.40%以下とすることが好ましい。
Sは、本発明における重要な元素である。Sは、Mnと結合してMnSを形成し、熱間鍛造後のオーステナイト粒内にもフェライトの生成核を増やすので、ベイナイトの生成を抑制することができる。さらには、MnSによって被削性も向上する。そのため、Sを0.008%以上含有させなくてはならない。一方、Sの含有量が0.030%以上になると、MnSは延伸された粗大な形態となるため、横目の疲労強度が低下して、横目の耐久比が低下する。したがって、Sの含有量は厳しく管理する必要があり、0.008%以上で0.030%未満とした。Sの含有量は0.010%以上であることが望ましく、0.027%以下であることが望ましい。
Crは、Mnと同様に、固溶強化によってフェライトおよびパーライトを強化し、熱間鍛造後の引張強度を高める元素であり、0.05%以上含有させなければならない。一方、Crの含有量が0.30%を超えると、その効果が飽和するばかりか、焼入れ性が高くなり、熱間鍛造後にベイナイトが生成して、横目の疲労強度の低下を招く場合がある。したがって、Crの含有量を0.05~0.30%とした。Crの含有量は0.08%以上とすることが好ましく、0.20%以下とすることが好ましい。Crの含有量は0.20%未満とすることがより好ましい。
Alは、脱酸作用を有するだけでなく、Nと結合してAlNを形成し、そのピンニング効果により熱間鍛造時のオーステナイト粒の成長を抑制し、ベイナイト生成を抑制する作用を有する。このため、Alは0.005%以上含有させなくてはならない。一方、Alの含有量が0.050%を超えると、その効果が飽和してしまう。したがって、Alの含有量を0.005~0.050%とした。Alの含有量は0.010%以上とすることが好ましい。
Vは、CおよびNと結合して、炭化物、窒化物または炭窒化物を形成して、熱間鍛造部品の横目の耐久比を有効に高める作用を有する。このため、0.200%以上のVを含有させる。一方、Vの含有量が0.320%を超えると、その効果が飽和するばかりか、コストの上昇を招く。したがって、Vの含有量を0.200~0.320%とした。Vの含有量は0.220%以上とすることが好ましく、0.300%以下とすることが好ましい。
Nは、本発明における重要な元素である。Nは、Vと結合して窒化物または炭窒化物を形成して、熱間鍛造部品の横目の耐久比を有効に高める作用を有するだけでなく、Alと結合してAlNを形成し、そのピンニング効果により熱間鍛造時のオーステナイト粒の成長を抑制し、ベイナイト生成を抑制する作用を有する。このため、0.0080%以上のNを含有させる必要がある。しかしながら、Nの含有量が多くなって、特に0.0200%を超えると、鋼中にピンホールが形成される場合がある。したがって、Nの含有量は0.0080~0.0200%とした。Nの含有量は0.0090%以上とすることが好ましく、0.0150%以下とすることが好ましい。
Pは、鋼中に不純物として含まれる元素であり、特に、その含有量が0.030%を超えると、偏析が著しくなり、疲労強度の低下を招く場合がある。したがって、不純物中のPの含有量を0.030%以下とした。不純物中のPの含有量は0.025%以下とすることが好ましい。不純物として含まれるPの含有量は、製鋼工程でのコスト上昇をきたさない範囲で、できる限り少なくすることが望ましい。
本発明において、Tiは、その含有量を制限しなければならない元素である。しかしながら、Tiは鉱石、スクラップ等からの混入を避けることができない。特に原料価格の抑制を重視して、スクラップの配合比率を増すと、不純物とはいえTiの混入量が高くなる。Tiの混入量が増えて、粗大なTi窒化物が形成されると、該Ti窒化物が熱間鍛造部品の軸方向に並んでしまい、特に0.0040%を上回ると、横目の疲労強度が低下し、0.47以上の横目の耐久比を得ることができない。そのため、不純物中のTiの含有量は、0.0040%以下とした。不純物中のTiの含有量は0.0035%以下とすることが好ましく、0.0030%未満とすることがより好ましい。
O(酸素)は、鋼中において、主として酸化物系介在物として存在し、横目の疲労強度の低下を招く不純物元素である。Oの含有量が多くなって、特に0.0020%を超えると、粗大な酸化物の発生頻度が高くなり、横目の疲労強度が低下し、横目の耐久比の低下を招く。したがって、不純物中のOの含有量を0.0020%以下とした。なお、不純物中のOの含有量は0.0015%以下とすることが好ましい。
Cuは、固溶強化によってフェライトおよびパーライトを強化する元素である。このため、Cuを含有させてもよい。しかしながら、Cuの含有量が0.30%を超えると、その効果が飽和するばかりか、焼入れ性が高くなり、熱間鍛造後にベイナイトが生成して、横目の疲労強度の低下を招く場合がある。したがって、含有させる場合のCuの量に上限を設け、0.30%以下とした。含有させる場合のCuの量は0.20%以下であることが好ましい。
Niは、固溶強化によってフェライトおよびパーライトを強化する元素である。このため、Niを含有させてもよい。しかしながら、Niの含有量が0.30%を超えると、その効果が飽和するばかりか、焼入れ性が高くなり、熱間鍛造後にベイナイトが生成して、横目の疲労強度の低下を招く場合がある。したがって、含有させる場合のNiの量に上限を設け、0.30%以下とした。含有させる場合のNiの量は0.20%以下であることが好ましい。
Moは、固溶強化によってフェライトおよびパーライトを強化する元素である。このため、Moを含有させてもよい。しかしながら、Moの含有量が0.10%を超えると、熱間鍛造後にベイナイトが生成して、横目の疲労強度の低下を招く場合がある。したがって、含有させる場合のMoの量に上限を設け、0.10%以下とした。含有させる場合のMoの量は0.08%以下であることが好ましい。
非調質熱間鍛造部品に、900MPa以上の引張強度を具備させるためには、該非調質熱間鍛造部品の素材である熱間鍛造用圧延棒鋼は、
Cu、NiおよびMoを含まない場合には、前記<1>式で表されるY1〔=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S〕が、
また、Cu、NiおよびMoのうちの1種以上を含む場合には、前記<2>式で表されるY2〔=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S+(1/5)Cu+(1/5)Ni+(1/4)Mo〕が、
それぞれ、1.05~1.18でなければならない。
上記厚さ18mmの鍛造品の、幅方向1/2の位置で、かつ厚さ方向1/2の位置から、10mm×10mmの横断面を有する試料を切り出した。次いで、上記の横断面が被検面になるように樹脂に埋め込み、鏡面研磨した後、3%硝酸アルコール(ナイタル)で腐食してミクロ組織を現出させた。その後、倍率を500倍として光学顕微鏡を用いて5視野についてミクロ組織画像を撮影し、「相」を同定した。
上記厚さ18mmの鍛造品の厚さ方向1/2の位置から、試験片の長手方向が鍛造品の幅方向、すなわち鍛造品の軸の垂直方向となり、また試験片の平行部の中心が鍛造品の幅方向1/2になるように、2011年1月21日に財団法人日本規格協会発行のJISハンドブック[1]鉄鋼IのJIS Z 2201(1998)に規定される14A号試験片(ただし、平行部直径:5mm)を採取した。そして、標点距離を25mmとして室温で引張試験を実施し、引張強度を求めた。鍛造品の引張強度の目標は、900MPa以上であることとした。
また、上記厚さ18mmの鍛造品の幅の両端をフライス加工して、スケールを除去するとともに平面に仕上げた。次いで、上記のフライス加工した鍛造品の両端とJIS G 4051(2009)に規定された市販のS10Cを電子ビーム溶接によって溶接し、幅130mmの板材を作製した。その後、上記板材の厚さ方向1/2の位置から、試験片の長手方向が板材の幅方向、すなわち鍛造品の軸の垂直方向となるように、また試験片の平行部の中心が板材の幅方向1/2になるように、平行部の直径が8mm、長さが106mmの小野式回転曲げ疲労試験片を作製した。
Claims (2)
- 質量%で、C:0.27~0.37%、Si:0.30~0.75%、Mn:1.00~1.45%、S:0.008%以上で0.030%未満、Cr:0.05~0.30%、Al:0.005~0.050%、V:0.200~0.320%およびN:0.0080~0.0200%と、
残部がFeおよび不純物とからなり、
不純物中のP、TiおよびOがそれぞれ、質量%で、P:0.030%以下、Ti:0.0040%以下およびO:0.0020%以下であり、
かつ、下記の<1>式で表されるY1が1.05~1.18の化学組成であることを特徴とする、熱間鍛造用圧延棒鋼。
Y1=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S・・・<1>
ただし、上記<1>式におけるC、Si、Mn、Cr、VおよびSは、それぞれの元素の質量%での含有量を表す。 - 質量%で、C:0.27~0.37%、Si:0.30~0.75%、Mn:1.00~1.45%、S:0.008%以上で0.030%未満、Cr:0.05~0.30%、Al:0.005~0.050%、V:0.200~0.320%およびN:0.0080~0.0200%と、
Cu:0.30%以下、Ni:0.30%以下およびMo:0.10%以下から選択される1種以上と、
残部がFeおよび不純物とからなり、
不純物中のP、TiおよびOがそれぞれ、質量%で、P:0.030%以下、Ti:0.0040%以下およびO:0.0020%以下であり、
かつ、下記の<2>式で表されるY2が1.05~1.18の化学組成であることを特徴とする、熱間鍛造用圧延棒鋼。
Y2=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S+(1/5)Cu+(1/5)Ni+(1/4)Mo・・・<2>
ただし、上記<2>式におけるC、Si、Mn、Cr、V、S、Cu、NiおよびMoは、それぞれの元素の質量%での含有量を表す。
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US10260123B2 (en) * | 2014-07-03 | 2019-04-16 | Nippon Steel & Sumitomo Metal Corporation | Rolled steel bar for machine structural use and method of producing the same |
US10266908B2 (en) * | 2014-07-03 | 2019-04-23 | Nippon Steel & Sumitomo Metal Corporation | Rolled steel bar for machine structural use and method of producing the same |
JP6551224B2 (ja) * | 2015-12-25 | 2019-07-31 | 日本製鉄株式会社 | 鋼管の製造方法 |
US11274354B2 (en) | 2016-04-05 | 2022-03-15 | Daido Steel Co., Ltd. | Steel material, crankshaft, and automobile component |
CN106978565A (zh) * | 2017-04-05 | 2017-07-25 | 宝钢特钢韶关有限公司 | 一种高强度非调质钢 |
JP7010298B2 (ja) * | 2017-10-31 | 2022-02-10 | 日本製鉄株式会社 | 熱間鍛造鋼材 |
CN113355596B (zh) * | 2021-05-22 | 2024-05-03 | 江苏铸鸿重工股份有限公司 | 一种合金钢锻圆调质处理工艺 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06287677A (ja) | 1993-04-01 | 1994-10-11 | Nippon Steel Corp | 高強度熱間鍛造用非調質鋼 |
JPH0892687A (ja) | 1994-09-22 | 1996-04-09 | Kobe Steel Ltd | 熱間鍛造用高強度高靭性非調質鋼とその製造方法 |
JPH09143610A (ja) * | 1995-11-15 | 1997-06-03 | Kobe Steel Ltd | 高疲労強度を有する熱間鍛造非調質鋼および鍛造品の製造方法 |
JP2000239782A (ja) * | 1999-02-16 | 2000-09-05 | Aichi Steel Works Ltd | 被削性と圧縮加工後の疲労強度に優れた非調質鍛造品の製造方法 |
JP2004137542A (ja) * | 2002-10-17 | 2004-05-13 | Sumitomo Metal Ind Ltd | 非調質鋼熱間鍛造部材の製造方法 |
JP2010007143A (ja) * | 2008-06-27 | 2010-01-14 | Kobe Steel Ltd | 疲労限度比と被削性に優れた機械構造用鋼 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09176875A (ja) * | 1995-12-21 | 1997-07-08 | Meidensha Corp | 薬剤投入酸洗装置 |
JP3235442B2 (ja) * | 1995-12-26 | 2001-12-04 | 住友金属工業株式会社 | 高強度・低延性非調質鋼 |
ATE442464T1 (de) * | 2005-03-09 | 2009-09-15 | Ovako Bar Oy Ab | Hochfester luftgekühlter stahl und daraus resultiertes warmverformte produkt. |
RU2437958C1 (ru) * | 2007-10-24 | 2011-12-27 | Ниппон Стил Корпорейшн | Нитроцементированная стальная деталь с индукционной закалкой с повышенной усталостной прочностью поверхности при высокой температуре и способ ее производства |
PL2246451T3 (pl) | 2008-02-26 | 2014-02-28 | Nippon Steel & Sumitomo Metal Corp | Kuta na gorąco mikrostopowa stal oraz stal walcowana na gorąco mająca doskonałą podatność na dzielenie metodą łamania i podatność na obróbkę maszynową, oraz część z niej |
JP5778055B2 (ja) * | 2012-02-15 | 2015-09-16 | 新日鐵住金株式会社 | 熱間鍛造用圧延棒鋼および熱間鍛造素形材ならびにコモンレールおよびその製造方法 |
-
2011
- 2011-11-21 JP JP2011253412A patent/JP5716640B2/ja active Active
-
2012
- 2012-11-07 HU HUE12852067A patent/HUE043166T2/hu unknown
- 2012-11-07 CN CN201280057256.5A patent/CN103958714B/zh active Active
- 2012-11-07 KR KR1020147013616A patent/KR20140079853A/ko not_active Application Discontinuation
- 2012-11-07 EP EP12852067.3A patent/EP2784169B1/en active Active
- 2012-11-07 WO PCT/JP2012/078789 patent/WO2013077182A1/ja active Application Filing
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Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06287677A (ja) | 1993-04-01 | 1994-10-11 | Nippon Steel Corp | 高強度熱間鍛造用非調質鋼 |
JPH0892687A (ja) | 1994-09-22 | 1996-04-09 | Kobe Steel Ltd | 熱間鍛造用高強度高靭性非調質鋼とその製造方法 |
JPH09143610A (ja) * | 1995-11-15 | 1997-06-03 | Kobe Steel Ltd | 高疲労強度を有する熱間鍛造非調質鋼および鍛造品の製造方法 |
JP2000239782A (ja) * | 1999-02-16 | 2000-09-05 | Aichi Steel Works Ltd | 被削性と圧縮加工後の疲労強度に優れた非調質鍛造品の製造方法 |
JP2004137542A (ja) * | 2002-10-17 | 2004-05-13 | Sumitomo Metal Ind Ltd | 非調質鋼熱間鍛造部材の製造方法 |
JP2010007143A (ja) * | 2008-06-27 | 2010-01-14 | Kobe Steel Ltd | 疲労限度比と被削性に優れた機械構造用鋼 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017188284A1 (ja) * | 2016-04-26 | 2017-11-02 | 新日鐵住金株式会社 | 高周波焼入れ用非調質鋼 |
Also Published As
Publication number | Publication date |
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KR20140079853A (ko) | 2014-06-27 |
JP5716640B2 (ja) | 2015-05-13 |
EP2784169A1 (en) | 2014-10-01 |
US9574255B2 (en) | 2017-02-21 |
JP2013108129A (ja) | 2013-06-06 |
EP2784169A4 (en) | 2016-03-16 |
HUE043166T2 (hu) | 2019-08-28 |
CN103958714B (zh) | 2016-03-23 |
EP2784169B1 (en) | 2019-01-09 |
US20140322066A1 (en) | 2014-10-30 |
CN103958714A (zh) | 2014-07-30 |
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