WO2016148206A1 - Acier durcissable par vieillissement, et procédé de fabrication de composants au moyen de l'acier durcissable par vieillissement - Google Patents

Acier durcissable par vieillissement, et procédé de fabrication de composants au moyen de l'acier durcissable par vieillissement Download PDF

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WO2016148206A1
WO2016148206A1 PCT/JP2016/058391 JP2016058391W WO2016148206A1 WO 2016148206 A1 WO2016148206 A1 WO 2016148206A1 JP 2016058391 W JP2016058391 W JP 2016058391W WO 2016148206 A1 WO2016148206 A1 WO 2016148206A1
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steel
age
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aging treatment
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将人 祐谷
幹 高須賀
泰三 牧野
真志 東田
長谷川　達也
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新日鐵住金株式会社
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Priority to JP2017506592A priority Critical patent/JP6465959B2/ja
Priority to EP16765035.7A priority patent/EP3272896B1/fr
Priority to US15/558,963 priority patent/US20180245172A1/en
Priority to ES16765035T priority patent/ES2769257T3/es
Publication of WO2016148206A1 publication Critical patent/WO2016148206A1/fr

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    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite

Definitions

  • the present invention relates to age-hardening steel. More specifically, after being processed into a predetermined shape by hot forging and cutting, an age hardening treatment (hereinafter simply referred to as “aging treatment”) is performed, and desired strength and toughness are ensured by the aging treatment. It relates to steel for manufacturing machine parts for automobiles, industrial machinery and construction machinery. The present invention also relates to a method for manufacturing a part using such age-hardening steel.
  • machine parts such as automobiles, industrial machines, and construction machines are required to have high fatigue strength. If the steel only has a high fatigue strength, it can be easily achieved by increasing the hardness of the steel using an alloy element and / or heat treatment. However, in general, a machine part is formed by hot forging and then finished into a predetermined product shape by cutting. For this reason, the steel used as the material for the machine parts must have sufficient machinability as well as high fatigue strength.
  • the higher the hardness of the material the better the fatigue strength.
  • cutting resistance and tool life tend to be inferior as the hardness of the material increases.
  • the precision-shaped mechanical components do not change dimensions during use. These precision-shaped machine parts may be momentarily subjected to a higher load than that normally used depending on the usage environment. Therefore, the yield strength is also necessary.
  • hardness can be kept low at the molding stage where good machinability is required, while strength is required by applying an aging treatment thereafter.
  • Various techniques have been disclosed that can increase the hardness in the final product stage.
  • Patent Document 1 discloses that after rolling, forging, or solution treatment, steel containing an amount of Mo and V, which are precipitation strengthening elements, limited by a specific relational expression.
  • the film is cooled at an average cooling rate of 0.05 to 10 ° C./second between a temperature of 800 ° C. and 300 ° C., and before the aging treatment, the area ratio of the bainite structure is 50% or more and the hardness is 40 HRC or less.
  • age-hardening steel characterized in that the aging treatment increases the hardness by 7 HRC or more than the hardness before the aging treatment.
  • Patent Document 2 describes precipitation as steel that is excellent in hot forgeability and machinability after hot forging, and can be strengthened by age hardening after machining. Bainite steel containing specific amounts of Mo and V as strengthening elements is disclosed.
  • Patent Document 3 discloses a steel containing Mo and V as an age-hardening type high-strength bainitic steel for hot forging, depending on the steel components after hot rolling or hot forging. Cooling is performed, the hardness is 400 HV or less, the structure is 70% or more of the bainite ratio, and the prior austenite crystal grain size is 80 ⁇ m or less. Therefore, an age-hardening type high-strength bainitic steel has been proposed in which the yield point or 0.2% proof stress is 900 MPa or more.
  • JP 2013-245363 A Patent Document 4
  • the content of the alloy element is adjusted so as to satisfy a specific parameter formula, so that the content of Mo is relatively small and after hot forging.
  • the hardness before the aging treatment is 290 HV or less and the hardness after the aging treatment is 325 HV or more, which can be expected to satisfy both high machinability and high fatigue strength.
  • Patent Document 5 optimizes the shape of V carbonitride having precipitation strengthening ability and the shape of bainite structure by cooling and heat treatment after hot forging, machinability, fatigue A machine structural steel component having both strength and toughness is disclosed.
  • Patent Document 6 Japanese Patent Application Laid-Open No. 2013-213254 is excellent in cold forgeability and chip disposal after cold forging, and has high core hardness, high surface hardness and deep effective hardening in cold forged and nitrided parts.
  • a steel for cold forging and nitriding that can have a layer depth is disclosed.
  • High fatigue strength and yield strength can be obtained by precipitating fine secondary phases in steel by aging treatment.
  • the toughness of steel strengthened by aging treatment deteriorates.
  • Patent Document 1 The steel disclosed in Patent Document 1 can obtain high age-hardening ability by adjusting the content of the alloy element so as to satisfy a specific parameter formula, but the toughness is not considered at all. .
  • Patent Document 2 adjusts the content of the alloy element so as to satisfy a specific parameter formula, so that the content of Mo is relatively low, and after aging treatment after hot forging and before aging treatment.
  • the hardness is 300 HV or less, and the hardness after aging treatment is 300 HV or more.
  • Patent Document 3 has a low C content of 0.06 to 0.20%, but the V content is very high at 0.51 to 1.00%, so age hardening However, it is not excellent in toughness.
  • Patent Document 4 The steel disclosed in Patent Document 4 is not sufficiently devised to increase the toughness and yield strength after aging treatment.
  • Patent Document 5 The steel disclosed in Patent Document 5 is not sufficiently devised to increase the yield strength after aging treatment.
  • Patent Document 6 Since the steel disclosed in Patent Document 6 has a low N content, the formation of nitrides is insufficient, and as a result, excellent yield strength has not been achieved.
  • an object of the present invention is to provide an age-hardening steel that satisfies the following ⁇ 1> to ⁇ 3>.
  • Hardness after hot forging related to cutting resistance and tool life is low.
  • the hardness after hot forging is referred to as “hardness before aging treatment”.
  • a machine part can have desired fatigue strength and yield strength by aging treatment.
  • the object of the present invention is to provide a JIS No. 14A tensile test having a hardness before aging treatment of 340 HV or less, a fatigue strength described later after aging treatment of 480 MPa or more, and a ⁇ 6 parallel portion.
  • a tensile test using a piece was performed, the 0.2% proof stress obtained by the offset method with the specified plastic strain amount being 0.2% was 800 MPa or more, and a notch depth of 2 mm described in JIS Z 2242
  • Elements that degrade toughness after aging treatment are C, V, Mo, and Ti.
  • C, V, Mo, and Ti combines with N and / or C to form TiN and / or TiC.
  • TiN and / or TiC is precipitated, the fatigue strength may be increased, but the toughness is greatly reduced.
  • the strength of the effect of deteriorating the toughness of Ti is extremely large. Therefore, Ti must be limited as much as possible.
  • C forms cementite in steel and can be the starting point of cleavage fracture. Even when steel containing an excessive amount of V or Mo with respect to the amount of C is aged, some cementite remains. V and Mo also precipitate the carbides on the same crystal plane of the matrix by aging treatment, thereby promoting the progress of cleavage fracture and degrading toughness. Therefore, in order to improve toughness, it is necessary to reduce the contents of C, V and Mo.
  • C and Mo have the effect of increasing the toughness by refining the structure and the effect of degrading toughness by precipitation as cementite or carbide. Overall, C greatly deteriorates toughness, and Mo slightly deteriorates toughness.
  • (C) Limitation of effective V ratio In order to make maximum use of precipitation strengthening by V, it is necessary to limit the effective V ratio defined as the amount of V solid solution with respect to the total amount of V.
  • a small effective V ratio means that the ratio of the amount of V contributing to precipitation strengthening is small and the strengthening ability is small, which is not preferable. There is no upper limit to the effective V ratio, and the closer to 1, the better.
  • the present invention has been made on the basis of the above findings (a) to (j), and the gist thereof is as follows.
  • the surface temperature after finish forging is 900 ° C. or higher.
  • a method for producing a part using age-hardening steel comprising:
  • the age-hardenable steel of the present invention has a hardness before aging treatment of 340 HV or less.
  • the mechanical parts using the age-hardening steel of the present invention have a fatigue strength of 490 MPa or more due to the aging treatment performed after the cutting process.
  • the mechanical part has a toughness (absorbed energy at 20 ° C. after aging treatment evaluated by a Charpy impact test performed using a standard test piece with a U-notch having a notch depth of 2 mm and a notch bottom radius of 1 mm) of 25 J. That's it.
  • the mechanical part has a yield strength of 800 MPa or more.
  • the age-hardening steel of the present invention can be used very suitably as a material for machine parts such as automobiles, industrial machines, and construction machines.
  • C 0.09 to 0.20%
  • C is an important element in the present invention.
  • C combines with V to form carbides and strengthens the steel.
  • the C content is less than 0.09%, V carbides are difficult to precipitate, and thus a desired strengthening effect cannot be obtained.
  • the C content is set to 0.09 to 0.20%.
  • the C content is preferably 0.10% or more, and more preferably 0.11% or more.
  • the C content is preferably 0.18% or less, and more preferably 0.16% or less.
  • Si 0.01-0.40% Si is useful as a deoxidizing element at the time of steel making, and at the same time, has an action of improving the strength of the steel by dissolving in a matrix.
  • Si needs to be contained in an amount of 0.01% or more.
  • the Si content is set to 0.01 to 0.40%.
  • the Si content is preferably 0.05% or more. Further, the Si content is preferably 0.35% or less, and more preferably 0.30% or less.
  • Mn 1.5 to 2.5%
  • Mn has the effect of improving hardenability and making the structure bainite. Furthermore, by lowering the bainite transformation temperature, the bainite structure can be refined to increase the toughness of the matrix. Moreover, Mn has the effect
  • S 0.001 to 0.045% Since S combines with Mn in steel to form MnS and improves chip disposability during cutting, it is necessary to contain 0.001% or more. However, when the S content increases, coarse MnS increases and deteriorates toughness and fatigue strength. In particular, when the S content exceeds 0.045%, the toughness and fatigue strength decrease remarkably. Therefore, the S content is set to 0.001 to 0.045%.
  • the S content is preferably 0.005% or more, and more preferably 0.010% or more. Further, the S content is preferably 0.040% or less, and more preferably 0.035% or less.
  • Cr More than 1.00% and 2.00% or less Cr, like Mn, has an effect of improving hardenability and making the structure bainite. Furthermore, the bainite structure is refined by lowering the bainite transformation temperature. Furthermore, the mobility of the grain boundary is lowered, the austenite grain size at the time of hot forging is refined, and as a result, the bainite structure after transformation is refined. Cr has the effect of increasing the toughness of the base material through the effect of refining these bainite structures. In order to obtain these effects sufficiently, it is necessary to contain more than 1.00%. However, if the Cr content exceeds 2.0%, the hardenability increases and the hardness before aging treatment may exceed 340 HV. Therefore, the Cr content is set to exceed Cr: 1.00% and not more than 2.00%. The Cr content is preferably 1.10% or more. The Cr content is preferably 1.80% or less, and more preferably 1.60% or less.
  • Al 0.001 to 0.060%
  • Al is an element having a deoxidizing action, and in order to obtain this effect, the content needs to be 0.001% or more. However, when Al is contained excessively, a coarse oxide is generated, and the toughness is lowered. Therefore, the Al content is set to 0.001 to 0.060%.
  • the Al content is preferably 0.050% or less.
  • V 0.22 to 0.55%
  • V is the most important element in the steel of the present invention.
  • V combines with C during the aging treatment to form fine carbides, thereby increasing the fatigue strength.
  • Mo when Mo is contained in the steel, V has an effect of further aging hardening ability by being combined with Mo and precipitated by aging treatment. In order to obtain these effects sufficiently, V needs to be 0.22% or more.
  • the V content is set to 0.22 to 0.55%.
  • the V content is preferably less than 0.45%, and more preferably 0.40% or less. Further, the V content is preferably 0.25% or more, and more preferably 0.27% or more.
  • N more than 0.0080 and 0.0170% or less N has the effect of promoting the precipitation of V carbonitride during aging and increasing the yield strength.
  • the N content needs to be more than 0.0080%.
  • the N content is set to more than 0.0080 and 0.0170% or less.
  • the N content is preferably 0.0090% or more, and more preferably 0.0100% or more.
  • the N content is preferably 0.0160% or less, and more preferably 0.0150% or less.
  • the age-hardenable steel of the present invention comprises the above-described elements from C to N, the balance Fe and impurities, and P and Ti in the impurities are P: 0.03% or less and Ti: 0.005%
  • the area ratio of the bainite structure is 80% or more, and the effective V ratio (V solid solution amount / V total amount) is 0.9 or more.
  • impurities refers to what is mixed from ore as a raw material, scrap, a manufacturing environment, etc. when manufacturing steel materials industrially.
  • P 0.03% or less
  • P is an element which is contained as an impurity and is not preferable in the present invention. That is, P reduces toughness by segregating at the grain boundaries. Therefore, the content of P is set to 0.03% or less.
  • the P content is preferably 0.025% or less.
  • Ti Less than 0.005% Ti is contained as an impurity and is an element that is not particularly preferable in the present invention. That is, Ti combines with N and / or C to form TiN and / or TiC, leading to a decrease in toughness. In particular, when the content is 0.005% or more, the toughness is greatly deteriorated. Therefore, the Ti content is less than 0.005%. In order to ensure good toughness, the Ti content is preferably 0.0035% or less.
  • the area ratio of the bainite structure is 80% or more.
  • the area ratio of the bainite structure means an area ratio when the metal structure at a position from the depth of 1/3 to 1/2 of the thickness from the surface of the steel material is observed with an optical microscope. If the area ratio of the bainite structure is 80% or more, precipitation of V is suppressed, the effective V ratio is increased, and high fatigue strength and 0.2% yield strength can be obtained.
  • the effective V ratio (V solid solution amount / V total amount) is 0.9 or more.
  • the effective V ratio means the amount of solid solution in the total amount of V contained in the steel. If the effective V ratio is 0.9 or more, the amount of V carbonitride precipitated by aging treatment increases, and high fatigue strength and 0.2% yield strength can be obtained.
  • Mo 0.9% or less Mo, like V, has a relatively low carbide precipitation temperature and is an element suitable for age hardening. Mo enhances hardenability, has the effect of increasing the area ratio while making the structure after hot forging bainite. Mo has a function of increasing age-hardening ability by forming carbides in combination with V in steel containing 0.22% or more of V. For this reason, you may contain Mo as needed. However, since Mo is a very expensive element, when the content increases, the manufacturing cost of steel increases and the toughness also decreases. Therefore, the Mo content in the case of inclusion is set to 0.9% or less. When Mo is contained, the amount of Mo is preferably 0.75% or less, more preferably 0.60% or less, and even more preferably less than 0.50%. On the other hand, in order to stably obtain the effect of Mo described above, the amount of Mo in the case of inclusion is desirably 0.05% or more, and more desirably 0.10% or more.
  • Cu 0.3% or less Cu has an effect of improving fatigue strength. For this reason, you may contain Cu as needed. However, when the Cu content increases, hot workability decreases. Therefore, the amount of Cu in the case of inclusion is set to 0.3% or less. When Cu is contained, the amount of Cu is preferably 0.25% or less. On the other hand, in order to stably obtain the effect of increasing the fatigue strength of Cu, the amount of Cu in the case of inclusion is preferably 0.1% or more.
  • Ni 0.3% or less Ni has an effect of improving fatigue strength. Furthermore, Ni also has the effect
  • the above Cu and Ni can be contained alone or in combination of two of them.
  • the total content of the above elements in the case of inclusion can be 0.6% in the case where the contents of Cu and Ni are the respective upper limit values.
  • Ca 0.005% or less Ca has an action of extending the tool life. For this reason, you may contain Ca as needed. However, when the content of Ca increases, a coarse oxide is formed and the toughness is deteriorated. Therefore, the Ca content in the case of inclusion is set to 0.005% or less. When Ca is contained, the amount of Ca is preferably 0.0035% or less. On the other hand, in order to stably obtain the effect of extending the life of the above-mentioned Ca tool, the Ca content in the case of inclusion is preferably 0.0005% or more.
  • Bi 0.4% or less Bi has the effect of reducing the cutting resistance and extending the tool life. For this reason, you may contain Bi as needed. However, when the Bi content is increased, the hot workability is lowered. Therefore, the amount of Bi when contained is set to 0.4% or less. When Bi is contained, the amount of Bi is preferably 0.3% or less. On the other hand, in order to stably obtain the effect of extending the life of the Bi tool, the amount of Bi in the case of inclusion is preferably 0.03% or more.
  • the above Ca and Bi can be contained in only one of them or in a combination of two.
  • the total content of these elements in the case of inclusion may be 0.405% in the case where the Ca and Bi contents are the respective upper limit values, but is preferably 0.3% or less. .
  • the element symbol in said (1) Formula and (1 ') Formula means content in the mass% of the element.
  • F1 and F1 ' are indices indicating the hardness before aging treatment. If the age-hardenable steel of the present invention satisfies the above-mentioned conditions regarding F1 or F1 ′, the hardness before aging treatment does not become too high, the cutting resistance at the time of cutting does not increase, and the tool life is increased. Is also realized.
  • FIG. 1 is a graph showing the relationship between the pre-aging hardness (vertical axis; HV) and the F1 values (horizontal axis) of various steel types. As is clear from the graph of FIG. 1, a strong first-order positive correlation is recognized between the two, and if F1 ⁇ 1.00 or less, the pre-aging hardness ⁇ 340 HV is satisfied. I understand.
  • the element symbol in said (2) Formula and (2 ') Formula means content in the mass% of the element.
  • F2 and F2 ' are indices indicating toughness after aging treatment. That is, if the condition of F1 or F1 'is satisfied, the toughness after the aging treatment may be lowered and the target toughness may not be ensured. Therefore, it is necessary to separately define F2 and F2'.
  • FIG. 2 is a diagram showing the relationship between the steel Charpy impact value after aging and the F2 value. As shown in the figure, there is also a positive correlation between the Charpy impact value (J) after aging treatment and the F2 value (horizontal axis), and when F2 or F2 ′ is less than 0.30, The toughness after the aging treatment cannot be obtained sufficiently. In order to ensure the target toughness while obtaining a yield strength of 800 MPa or more, the content of each alloy element is within the specified range, and F1 or F1 ′ is satisfied. Alternatively, it is necessary to satisfy the condition of F2 ′.
  • F2 and F2 ' are preferably 0.45 or more, and more preferably 0.60 or more.
  • the method for producing the age-hardening steel of the present invention is not particularly limited, and the chemical composition may be adjusted by melting by a general method.
  • a material for hot forging (hereinafter referred to as “hot forging material”) is produced from steel whose chemical composition is adjusted to the above-mentioned range.
  • the material for hot forging billets obtained by performing ingot rolling on ingots, billets obtained by performing ingot rolling on continuous cast materials, or steel bars obtained by hot rolling or hot forging these billets can be used.
  • the above hot forging material is hot forged, and further cut to finish the workpiece into a predetermined part shape.
  • the hot forging is performed, for example, by heating the hot forging material at 1100 to 1350 ° C. for 0.1 to 300 minutes, so that the surface temperature after finish forging becomes 900 ° C. or higher, and then 800 Cool to room temperature with an average cooling rate in the temperature range from ⁇ 400 ° C. at 10-90 ° C./min.
  • the workpiece cooled as described above is further cut to finish a predetermined part shape.
  • the workpiece is subjected to an aging treatment to obtain machine parts such as automobiles, industrial machines, and construction machines having desired characteristics.
  • the aging treatment is performed, for example, in a temperature range of 540 to 700 ° C., preferably in a temperature range of 560 to 680 ° C.
  • the holding time of this aging treatment is adjusted according to the size (mass) of the machine part for soaking, but can be 30 to 1000 minutes.
  • Steels 1 to 27 having chemical compositions shown in Table 1 were melted in a 50 kg vacuum melting furnace.
  • Steels 1 to 17 in Table 1 are steels whose chemical compositions are within the range defined by the present invention.
  • steels 18 to 27 in Table 1 are steels whose chemical compositions deviate from the conditions defined in the present invention.
  • Each ingot of each steel type was heated at 1250 ° C. and then hot forged into a steel bar having a diameter of 60 mm.
  • Each hot forged steel bar was once allowed to cool in the atmosphere and cooled to room temperature. Thereafter, heating was performed at 1250 ° C. for 30 minutes, and forging into a part shape was assumed, and the surface temperature of the forged material at the time of finishing was set to 950 to 1100 ° C., and hot forging into a steel bar having a diameter of 35 mm. After hot forging, all were allowed to cool in air and cooled to room temperature.
  • the cooling rate when allowed to cool in the atmosphere is that of hot forging again by embedding a thermocouple in the vicinity of R / 2 of the steel bar hot-forged under the above conditions ("R" represents the radius of the steel bar).
  • R represents the radius of the steel bar.
  • the temperature was raised to a temperature close to the finishing temperature and then allowed to cool in the air for measurement.
  • the average cooling rate in the temperature range from 800 to 400 ° C. after forging measured in this way was about 40 ° C./min.
  • a part of the steel bar cooled to room temperature after finishing to a diameter of 35 mm by hot forging is cut off by 100 mm at both ends of the steel bar without being subjected to an aging treatment (that is, in a cooled state). After that, a test piece was cut out from the remaining central portion, and the hardness before aging treatment was investigated.
  • the remainder of the hot-forged bar steel is subjected to aging treatment at 600 to 630 ° C. for 60 to 180 minutes, and both ends of the bar steel are cut off by 100 mm each, and then a specimen is cut out from the remaining central portion.
  • the hardness after aging treatment was investigated.
  • the test piece was cut out from the bar steel, and the absorbed energy, fatigue strength, and yield strength in the Charpy impact test after the aging treatment were investigated.
  • Hardness measurement was performed as follows. First, a test piece was prepared by crossing a steel bar, filling the resin so that the cut surface became the test surface, and mirror polishing. Next, in accordance with “Vickers hardness test-test method” in JIS Z 2244 (2009), the test force is 9 for 10 points near the R / 2 part (“R” represents the radius) of the test surface. The hardness was measured as 8N. The above 10 points were arithmetically averaged to obtain Vickers hardness. When the hardness before aging treatment was 340 HV or less, it was judged that even parts that were machined under various conditions could be industrially mass-produced, and this was the target. When the specimens after the hardness measurement were corroded with the nital and the structure was observed, the specimens of all steel types were mainly bainite and some MA structures were mixed.
  • the toughness after the aging treatment is evaluated by a Charpy impact test conducted using a standard test piece with a U-notch having a notch depth of 2 mm and a notch bottom radius of 1 mm, and the absorbed energy at a test temperature of 20 ° C. is 25 J or more. Judged that it was high enough, and aimed this.
  • the fatigue strength was investigated by preparing an Ono-type rotating bending fatigue test piece having a parallel part diameter of 8 mm and a length of 106 mm.
  • the above test piece was collected so that the center of the fatigue test piece was R / 2 part of the steel bar, the number of tests was set to 8, and the Ono type rotation was performed under the conditions that the stress ratio was -1 at room temperature and in air A bending fatigue test was performed.
  • the maximum value of the stress amplitude when the number of repetitions was not broken up to 1.0 ⁇ 10 7 times was defined as the fatigue strength.
  • the fatigue strength was 490 MPa or more, it was judged that the fatigue strength was sufficiently high, and this was the target.
  • the age-hardening steel of the present invention can ensure a suitable hardness before aging treatment (340 HV or less), and can be expected to reduce cutting resistance and extend the tool life. Moreover, if the age-hardening steel of the present invention is used, a suitable fatigue strength (490 MPa or more), yield strength (800 MPa or more), and impact value (25 J or more) are also obtained by an aging treatment performed after cutting. Can be secured. For this reason, the age-hardening steel of the present invention can be used very suitably as a material for machine parts such as automobiles, industrial machines, and construction machines.

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Abstract

La présente invention concerne un acier durcissable par vieillissement qui a une faible dureté après forgeage à chaud, qui, au moyen d'un traitement de vieillissement, confère à des composants mécaniques la résistance à la fatigue et la limite d'élasticité souhaitées, et qui a une ténacité élevée après un traitement de vieillissement. L'acier comprend C : 0,09 à 0,20 %, Si : 0,01 à 0,40 %, Mn : 1,5 à 2,5 %, S : 0,001 à 0,045 %, Cr : de plus de 1,00 à 2,00 %, Al : 0,001 à 0,060 %, V : 0,22 à 0,55 % et N : de plus de 0,0080 à 0,0170 %, le reste étant Fe et des impuretés. Le rapport de surface de la structure de bainite est de 80 % ou plus. La proportion de V efficace (quantité de solution solide de V/quantité totale de V) est de 0,9 ou plus. Les quantités de P et Ti dans les impuretés sont P : 0,03 % ou moins, et Ti : moins de 0,005 %. L'acier a une composition chimique dans laquelle F1 décrit ci-après est de 1,00 ou moins, et F2 décrit ci-après est de 0,30 ou plus. F1 = C + 0,1 × Si + 0,2 × Mn + 0,15 × Cr + 0,35 × V F2 = -4,5 × C + Mn + Cr - 3,5 × V
PCT/JP2016/058391 2015-03-16 2016-03-16 Acier durcissable par vieillissement, et procédé de fabrication de composants au moyen de l'acier durcissable par vieillissement WO2016148206A1 (fr)

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JP2017506592A JP6465959B2 (ja) 2015-03-16 2016-03-16 時効硬化性鋼及び時効硬化性鋼を用いた部品の製造方法
EP16765035.7A EP3272896B1 (fr) 2015-03-16 2016-03-16 Acier durcissable par vieillissement, et procédé de fabrication de composants au moyen de l'acier durcissable par vieillissement
US15/558,963 US20180245172A1 (en) 2015-03-16 2016-03-16 Age-hardenable steel, and method for manufacturing components using age-hardenable steel
ES16765035T ES2769257T3 (es) 2015-03-16 2016-03-16 Acero endurecible por envejecimiento, y método para fabricar componentes que incluyen acero endurecible por envejecimiento

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CN111836908A (zh) * 2018-03-23 2020-10-27 安赛乐米塔尔公司 贝氏体钢的锻造部件及其制造方法
WO2021117243A1 (fr) * 2019-12-13 2021-06-17 日本製鉄株式会社 Acier à durcissement par vieillissement, acier et composant mécanique

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CA2995917C (fr) * 2015-08-24 2020-04-14 Nippon Steel & Sumitomo Metal Corporation Essieu ferroviaire
CN110257713A (zh) * 2019-07-16 2019-09-20 内蒙古科技大学 一种低碳时效钢及其制备方法

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JP2000017374A (ja) * 1998-06-26 2000-01-18 Aichi Steel Works Ltd 時効硬化型高強度ベイナイト鋼およびその製造方法
JP2011241441A (ja) * 2010-05-18 2011-12-01 Sumitomo Metal Ind Ltd 時効硬化性鋼および機械部品の製造方法
JP2012193416A (ja) * 2011-03-17 2012-10-11 Sumitomo Metal Ind Ltd 時効硬化性鋼および機械部品の製造方法
WO2012161323A1 (fr) * 2011-05-26 2012-11-29 新日鐵住金株式会社 Élément en acier pour utilisation structurale mécanique et son procédé de fabrication
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JPH04154936A (ja) * 1990-10-16 1992-05-27 Aichi Steel Works Ltd 析出硬化型窒化用鋼
JP2000017374A (ja) * 1998-06-26 2000-01-18 Aichi Steel Works Ltd 時効硬化型高強度ベイナイト鋼およびその製造方法
JP2011241441A (ja) * 2010-05-18 2011-12-01 Sumitomo Metal Ind Ltd 時効硬化性鋼および機械部品の製造方法
JP2012193416A (ja) * 2011-03-17 2012-10-11 Sumitomo Metal Ind Ltd 時効硬化性鋼および機械部品の製造方法
WO2012161323A1 (fr) * 2011-05-26 2012-11-29 新日鐵住金株式会社 Élément en acier pour utilisation structurale mécanique et son procédé de fabrication
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WO2021117243A1 (fr) * 2019-12-13 2021-06-17 日本製鉄株式会社 Acier à durcissement par vieillissement, acier et composant mécanique

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