WO2022210793A1 - 鉄鋳物 - Google Patents

鉄鋳物 Download PDF

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Publication number
WO2022210793A1
WO2022210793A1 PCT/JP2022/015705 JP2022015705W WO2022210793A1 WO 2022210793 A1 WO2022210793 A1 WO 2022210793A1 JP 2022015705 W JP2022015705 W JP 2022015705W WO 2022210793 A1 WO2022210793 A1 WO 2022210793A1
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Prior art keywords
heat treatment
mass
casting
heat
examples
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Ceased
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PCT/JP2022/015705
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English (en)
French (fr)
Japanese (ja)
Inventor
拓郎 梅谷
理恵 西尾
保彦 中村
文雄 橋本
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HINODE HOLDINGS CO Ltd
Yamagata Seimitsu Cyuzou Co Ltd
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HINODE HOLDINGS CO Ltd
Yamagata Seimitsu Cyuzou Co Ltd
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Priority to CN202280015514.7A priority Critical patent/CN116867920A/zh
Priority to JP2023511432A priority patent/JP7743971B2/ja
Publication of WO2022210793A1 publication Critical patent/WO2022210793A1/ja
Anticipated expiration legal-status Critical
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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
    • C21D6/00—Heat treatment of ferrous alloys
    • 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
    • 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
    • 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

Definitions

  • the present invention relates to an iron casting manufactured using a ferritic casting material.
  • Patent Document 1 describes providing a heat-resistant cast steel with excellent thermal fatigue resistance. Further, in the abstract of Patent Document 1, the contents of C, Si, Mn, P, S and Cr are respectively 0.10 wt% ⁇ C ⁇ 0.30 wt%, 2.0 wt% ⁇ Si ⁇ 4 0% by weight, 0.3% by weight ⁇ Mn ⁇ 1.0% by weight, P ⁇ 0.04% by weight, S ⁇ 0.30% by weight, 5.0% by weight ⁇ Cr ⁇ 15.0% by weight , and the balance is substantially Fe, and the cast structure of the matrix is a mixed phase structure consisting of ferrite phase and pearlite phase, thereby extending the thermal fatigue life of the heat-resistant cast steel and improving the room temperature elongation. It is described that the thermal fatigue resistance can be improved by
  • One aspect of the present invention is an iron casting obtained by performing a first heat treatment on a heat-treated object cast using a ferritic casting material.
  • the casting material contains 0.0001-0.03 wt% C, 0.001-0.6 wt% Ni, 16.0-21.0 wt% Cr, the balance being Fe and It is an unavoidable element.
  • Performing the first heat treatment includes holding the heat-treated object in a first temperature range of 750 to 1380.degree.
  • the heat treatment target The ferrite phase is crystallized as the main phase in the material. Furthermore, when the liquid phase solidifies in the process of crystallization of the ferrite phase, the solute element dissolved in a non-uniform concentration distribution inside the crystal grain that constitutes the ferrite phase (hereinafter referred to as "inside the crystal grain") By performing the first heat treatment at a temperature of 750 to 1380° C. and maintaining the temperature in the first temperature range of 750 to 1380° C., the solute element is dissolved in the crystal grains with high uniformity.
  • holding the heat-treated object in the first temperature range includes holding the heat-treated object for a first time range of 0.5 to 6.0 hours.
  • the iron casting is preferably obtained by subjecting the heat-treated object to the second heat treatment after the first heat treatment.
  • performing the second heat treatment includes holding the heat-treated object at a second temperature range of 20 to 1080°C.
  • a second heat treatment is performed on the solute elements distributed in the grains of the ferrite phase or at the boundaries of the grains (hereinafter referred to as "grain boundaries"), and held at a second temperature range of 20 to 1080 ° C. controls the segregation of solute elements in grains or grain boundaries.
  • grain boundaries the solute elements distributed in the grains of the ferrite phase or at the boundaries of the grains (hereinafter referred to as "grain boundaries")
  • grain boundaries the solute elements distributed in the grains of the ferrite phase or at the boundaries of the grains
  • holding the heat-treated object in the second temperature range includes holding the heat-treated object for a second time range of 0.3 to 48 hours.
  • the casting material preferably further contains 0.0001 to 0.03% by mass of N.
  • the content of N in the casting material 0.0001 to 0.03% by mass, the amount of solidified segregation of N is reduced, and a small amount of N solidified and segregated in the crystal grains is treated by the first method.
  • the heat treatment can reliably reduce the segregation of N in the crystal grains.
  • the casting material preferably further contains 0.001 to 1.0% by mass of Mn. Precipitation of the austenite phase can be suppressed by setting the Mn content in the casting material to 0.001 to 1.0% by mass. Therefore, it is easy to stabilize the ferrite phase from the normal temperature range to the high temperature range, and it is easy to suppress the phase transformation that accompanies the first heat treatment. Therefore, a decrease in ductility due to phase transformation can be suppressed.
  • the casting material preferably further contains 0.1-0.3% by mass of Ti.
  • the Ti content in the casting material 0.1 to 0.3% by mass, it is possible to refine the crystal grains and increase the proportion of crystal grain boundaries in the ferrite phase. Therefore, it is easy to reduce the segregation concentration of the solute element at the grain boundary. Therefore, it is easy to improve the elongation of iron castings.
  • Another aspect of the present invention is an iron casting obtained by subjecting a heat-treated object cast using a ferritic casting material to a first heat treatment, wherein the first heat treatment includes: An iron casting comprising holding a heat treated object in a first temperature range of 750-1380°C.
  • the iron casting is preferably obtained by subjecting the heat-treated object to the second heat treatment after the first heat treatment.
  • performing the second heat treatment includes holding the heat-treated object at a second temperature range of 20 to 1080°C.
  • FIG. 1 is a diagram showing the compositions of the first embodiment (Examples 1-7) and the second embodiment (Example 8), and the compositions of Comparative Examples 1-2.
  • FIG. 2 shows the heat treatment conditions and mechanical properties of the first embodiment (Examples 1 to 7) and the second embodiment (Example 8), and the heat treatment conditions and mechanical properties of Comparative Examples 1 and 2.
  • FIG. 4 is a diagram showing; FIG. 3A shows the compositions of the third embodiment (Examples 9-43).
  • FIG. 3B shows the compositions of the third embodiment (Examples 44-77).
  • FIG. 3C is a diagram showing the compositions of the fourth embodiment (Examples 78-105) and the compositions of Comparative Examples 3-5.
  • FIG. 4A is a diagram showing the heat treatment conditions and mechanical properties of the third embodiment (Examples 9-43).
  • FIG. 4B is a diagram showing the heat treatment conditions and mechanical properties of the third embodiment (Examples 44-77).
  • FIG. 4C is a diagram showing the heat treatment conditions and mechanical properties of the fourth embodiment (Examples 78-105) and the heat treatment conditions and mechanical properties of Comparative Examples 3-5.
  • the material used to manufacture the iron casting according to the embodiment of the present invention is a ferritic casting material.
  • “Ferritic casting material” means a casting material having a ferrite phase as a main phase.
  • the ferrite phase accounts for 50% or more of the entire structure.
  • the ratio of the ferrite phase in the entire structure is preferably 70% or more, more preferably 80% or more, more preferably 85% or more, more preferably 90% or more, 92 It is more preferably 0.5% or more, more preferably 95% or more, more preferably 97.5% or more, even more preferably 99% or more.
  • casting includes casting by various casting methods such as sand casting, metal mold casting, die casting, and lost wax casting.
  • % by mass of an element means the percentage of the mass of the element with respect to the mass of the ferritic casting material.
  • the notation “X to Y mass % of an element” means that the mass % of the element is X % or more and Y % or less.
  • the "remainder” means the components other than the listed elements among the components constituting the ferritic casting material. Therefore, for example, the notation "including . . . C, . . . Ni, and . , means that components other than Ni and Cr are Fe and inevitable elements.
  • the notation "X to Y ° C.” in the heat treatment conditions means that the holding temperature is X ° C. or more and Y ° C. or less
  • the notation "X to Y hours” means that the holding time is X hours or more and Y hours or less.
  • a first form of a ferritic casting material (hereinafter referred to as "this material") contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 0.03% by mass of Si.
  • this material contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 0.03% by mass of Si.
  • a first form of the material contains 0.0001 to 0.03 wt% C.
  • C carbon
  • a first form of the present material contains 0.0001 to 0.03 wt% C.
  • C is fixed together with N as Nb carbonitrides, thereby reducing the formation of Cr carbonitrides. be able to. Therefore, it is possible to suppress the decrease in the Cr content in the ferrite phase. Therefore, deterioration of the corrosion resistance of iron castings can be suppressed.
  • the upper limit of the C content to 0.03% by mass, it is possible to suppress the precipitation of the austenite phase in the high temperature range.
  • the upper limit of the C content is preferably 0.02% by mass. Precipitation of Cr carbonitrides and Nb carbonitrides can be further suppressed. Therefore, deterioration in corrosion resistance and embrittlement of iron castings can be further suppressed. The same applies to the following forms of the present material.
  • Si silicon
  • a first form of this material contains 0.001 to 1.0% Si by weight.
  • the upper limit of the Si content is set to 1.0% by mass, it is possible to suppress an increase in the solid solution amount of Si in the ferrite phase. Therefore, it is possible to suppress the decrease in ductility of the iron casting and the occurrence of weld cracks.
  • the upper limit of the Si content is set to 1.0% by mass, aggregation of non-metallic inclusions (oxides) such as silicon dioxide can be suppressed. Therefore, it is possible to suppress the occurrence of surface defects and internal defects in iron castings.
  • the lower limit of the Si content is preferably 0.4% by mass.
  • Non-metallic inclusions such as silicon dioxide can act as precipitation nuclei for Nb carbonitride. Therefore, aggregation of Nb carbonitrides is suppressed, and the Nb carbonitrides are easily dispersed uniformly in the crystal grains. Therefore, by suppressing excessive growth of Nb carbonitrides in crystal grains, brittle fracture of iron castings can be suppressed.
  • the upper limit of the Si content is preferably 0.6% by mass.
  • the Nb carbonitrides can be more uniformly dispersed in the crystal grains, and excessive growth of the Nb carbonitrides can be further suppressed. The same applies to the following forms of the present material.
  • a first form of this material contains 0.001 to 1.0% by weight Mn.
  • precipitation of the austenite phase can be suppressed by setting the upper limit of the content of Mn, which is an austenitizing element, to 1.0% by mass. Therefore, the ferrite phase can be stabilized over the normal temperature range to the high temperature range.
  • the upper limit of the Mn content is set to 1.0% by mass, excessive generation of non-metallic inclusions (sulfides) such as manganese sulfide formed by Mn, which tends to segregate in the final solidified portion, together with S is suppressed. can do.
  • the upper limit of the Mn content is preferably 0.2% by mass, more preferably 0.15% by mass. It is possible to reduce the amount of non-metallic inclusions such as manganese sulfide that precipitate at grain boundaries. Therefore, non-metallic inclusions such as silicon dioxide tend to act preferentially as precipitation nuclei for Nb carbonitrides, and Nb carbonitrides tend to be uniformly dispersed in crystal grains. The same applies to the following forms of the present material.
  • a first form of this material contains 0.0001 to 0.04% by weight P.
  • P Phosphorus
  • a first form of this material contains 0.0001 to 0.04% by weight P.
  • the upper limit of the P content is preferably 0.03% by mass. Embrittlement of iron castings can be further suppressed. The same applies to the following forms of the present material.
  • a first form of this material contains 0.0001 to 0.027% by weight S.
  • S sulfur
  • a first form of this material contains 0.0001 to 0.027% by weight S.
  • non-metallic inclusions such as manganese sulfide (sulfidation substance) can be suppressed. For this reason, it is possible to suppress excessive precipitation of Nb carbonitrides in grains or grain boundaries using nonmetallic inclusions such as manganese sulfide as precipitation nuclei. Therefore, it is possible to suppress the occurrence of intergranular embrittlement caused by Nb carbonitrides precipitated at grain boundaries.
  • the upper limit of the S content is preferably 0.025% by mass, more preferably 0.020% by mass, and even more preferably 0.015% by mass.
  • the lower limit of the S content is preferably 0.001% by mass, more preferably 0.004% by mass. It is possible to reduce the amount of non-metallic inclusions such as manganese sulfide that precipitate at grain boundaries. The same applies to the following forms of the present material.
  • a first form of this material contains 0.3 to 0.8% Cu by weight.
  • the corrosion resistance of iron castings can be improved by setting the Cu content to 0.3 to 0.8% by mass.
  • the lower limit of the Cu content is preferably 0.4% by mass.
  • a decrease in the corrosion resistance of iron castings can be suppressed.
  • the upper limit of the Cu content is preferably 0.5% by mass. Precipitation of Cu can be suppressed, and a decrease in ductility of iron castings can be suppressed. The same applies to the following forms of the present material.
  • Ni nickel
  • a first form of this material contains 0.001 to 0.6 wt% Ni.
  • precipitation of the austenite phase can be suppressed by setting the upper limit of the content of Ni, which is an austenitizing element, to 0.6% by mass. Therefore, the ferrite phase can be stabilized over the normal temperature range to the high temperature range.
  • the upper limit of the Ni content is preferably 0.4% by mass, more preferably 0.3% by mass. It is possible to improve the corrosion resistance of iron castings while suppressing an increase in alloy costs. The same applies to the following forms of the present material.
  • a first form of this material contains 16.0-21.0% by weight Cr.
  • the content of Cr which is a ferritizing element, is 16.0 to 21.0% by mass, so that the ferrite phase can be stabilized over the normal temperature range to the high temperature range.
  • the lower limit of the Cr content is preferably 18.0% by mass.
  • the corrosion resistance of iron castings can be further improved.
  • the upper limit of the Cr content is preferably 19.0% by mass. It is possible to suppress the precipitation of embrittlement phases such as the ⁇ phase and suppress the decrease in ductility of iron castings. The same applies to the following forms of the present material.
  • Nb niobium
  • a first form of this material contains 0.3-0.8% by weight of Nb.
  • Nb niobium
  • the upper limit of the Nb content is preferably 0.6% by mass, more preferably 0.4% by mass. It is possible to suppress the deterioration of the ductility of iron castings due to excessive solid-solution strengthening and excessive generation of Nb carbonitrides, and also suppress the occurrence of weld cracks. The same applies to the following forms of the present material.
  • N nitrogen
  • a first form of this material contains 0.0001-0.03% by weight N.
  • the formation of Cr carbonitrides formed by N together with C can be reduced. Therefore, it is possible to suppress the decrease in the Cr content in the ferrite phase. Therefore, deterioration of the corrosion resistance of iron castings can be suppressed.
  • the upper limit of the N content to 0.03% by mass, it is possible to suppress the precipitation of the austenite phase in the high temperature range. Therefore, by reducing the ratio of the austenite phase, which tends to reduce the diffusion rate of Cr, it is possible to ensure the amount of Cr supplied to the oxide film of the iron casting.
  • the corrosion resistance of iron castings can be improved.
  • excessive production of Nb carbonitrides formed by N together with C can be suppressed. Therefore, excessive precipitation of Nb carbonitride in grains and grain boundaries can be suppressed. Therefore, it is possible to suppress the decrease in ductility of the iron casting and the occurrence of weld cracks.
  • excessive generation of Nb carbonitrides can be suppressed, it is possible to suppress a decrease in the solid solution amount of Nb in the ferrite phase. Therefore, the high temperature strength of the iron casting can be improved.
  • the upper limit of the N content is preferably 0.02% by mass. Precipitation of Cr carbonitrides and Nb carbonitrides can be further suppressed. Therefore, deterioration in corrosion resistance and embrittlement of iron castings can be further suppressed. The same applies to the following forms of the present material.
  • the balance in the first form of this material is Fe and unavoidable elements.
  • inevitable elements contained in the balance include Al (aluminum), Mo (molybdenum), V (vanadium), Co (cobalt), Sn (tin), Ce (cerium), Te (tellurium), and La (lanthanum). , Bi (bismuth), and Zn (zinc).
  • the content of the inevitable elements is, for example, preferably 5.0% by mass or less in total, more preferably 3.0% by mass or less in total, and 1.0% by mass or less in total. More preferably, the total amount is 0.5% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less. The same applies to the following forms of the present material.
  • a second form of this material is 0.0001-0.03 wt% C, 0.001-1.0 wt% Si, 0.001-1.0 wt% Mn, and 0.001-1.0 wt% Si. 0001 to 0.04 wt% P, 0.0001 to 0.027 wt% S, 0.3 to 0.8 wt% Cu, 0.001 to 0.6 wt% Ni, 16.0-21.0 wt% Cr, 0.3-0.8 wt% Nb, 0.0001-0.03 wt% N, 0.1-0.3 wt% Ti and the balance is Fe and unavoidable elements.
  • Ti titanium
  • a second form of this material contains 0.1-0.3% Ti by weight.
  • the Ti content By setting the Ti content to 0.1 to 0.3% by mass, it is possible to refine the crystal grains and increase the ratio of crystal grain boundaries in the ferrite phase. . Therefore, it is easy to reduce the segregation concentration of the solute element at the grain boundary. Therefore, it is easy to improve the elongation of iron castings.
  • the lower limit of the Ti content By setting the lower limit of the Ti content to 0.1% by mass, it is possible to promote refinement of crystal grains.
  • the upper limit of the Ti content By setting the upper limit of the Ti content to 0.3% by mass, it is possible to suppress the decrease in ductility of iron castings due to excessive solid-solution strengthening and excessive generation of Ti oxides, and to suppress the occurrence of weld cracks.
  • the upper limit of the C content is set to 0.03% by mass
  • the upper limit of the N content is set to 0.03% by mass
  • the Ti content is set to 0.1 to 0.3% by mass.
  • the present material is not limited to the form described above.
  • the material contains one or more of the elements C, Si, Mn, P, S, Cu, Ni, Cr, Nb, N and Ti, and the balance is Fe and unavoidable elements. good.
  • An example of another form of the material contains 0.0001-0.03 wt% C, 0.001-0.6 wt% Ni, and 16.0-21.0 wt% Cr. , the remainder being Fe and unavoidable elements.
  • an example of another form of this material is 0.0001 to 0.03% by mass of C, 0.001 to 0.6% by mass of Ni, and 16.0 to 21.0% by mass of Cr. , 0.1 to 0.3% by mass of Ti, the balance being Fe and unavoidable elements.
  • an example of another form of this material is 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Mn, and 0.001 to 0.6% by mass of Ni. , 16.0-21.0% by mass of Cr, 0.0001-0.03% by mass of N, and the balance being Fe and unavoidable elements.
  • an example of another form of this material is 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Mn, and 0.001 to 0.6% by mass of Ni. , containing 16.0 to 21.0% by mass of Cr, 0.0001 to 0.03% by mass of N, and 0.1 to 0.3% by mass of Ti, the balance being Fe and unavoidable elements .
  • a first form of heat treatment (hereinafter referred to as "main heat treatment") performed on a heat treatment object cast using the present material is a first heat treatment (solution treatment, primary heat treatment) on the heat treatment object. Including doing.
  • Performing the first heat treatment includes holding the heat-treated object in a first temperature range of 750 to 1380.degree. Holding the first temperature range includes holding the heat-treated object for a first time range of 0.5 to 6.0 hours.
  • a casting material with a Ni content of 0.001 to 0.6% by mass and a Cr content of 16.0 to 21.0% by mass is used before performing the first heat treatment.
  • a ferrite phase is crystallized as a main phase in the heat-treated object by casting the heat-treated object.
  • the solute element dissolved in the crystal grains constituting the ferrite phase with a non-uniform concentration distribution is Then, the first heat treatment is performed. Since performing the first heat treatment includes holding the heat treatment object in the first temperature range of 750 to 1380° C., the solute element can be solid-solved in the crystal grains with high uniformity. This can reduce the segregation of solute elements in the crystal grains. As a result, the elongation of iron castings can be improved. The same applies to the following modes of this heat treatment.
  • the upper limit of the content of Ni, which is an austenitizing element, is set to 0.6% by mass
  • the content of Cr, which is a ferritizing element is set to 16.0 to 21.0% by mass. Therefore, the ferrite phase can be stabilized from the normal temperature range to the high temperature range. Therefore, it is easy to suppress the phase transformation that accompanies the first heat treatment. Therefore, a decrease in ductility due to phase transformation can be suppressed. The same applies to the following modes of this heat treatment.
  • a casting material having a C content of 0.0001 to 0.03% by mass and an N content of 0.0001 to 0.03% by mass before performing the first heat treatment can reduce the amount of solidification segregation of C and N in the heat treatment object.
  • the first heat treatment is performed on C and N solidified and segregated in the crystal grains, albeit in very small amounts. Thereby, the segregation of C and N in the crystal grains can be reduced with high certainty. The same applies to the following modes of this heat treatment.
  • the upper limit of the first temperature range is preferably 1350°C, more preferably 1300°C, more preferably 1250°C, more preferably 1200°C, and preferably 1150°C. More preferably, it is 1125°C even more preferably.
  • the lower limit of the first temperature range is preferably 775°C, more preferably 800°C, more preferably 850°C, more preferably 900°C, and more preferably 950°C. It is more preferably 1000°C, more preferably 1050°C, even more preferably 1075°C. The same applies to the following modes of this heat treatment.
  • the upper limit of the first time range is preferably 5.5 hours, more preferably 5.0 hours, more preferably 4.5 hours, more preferably 4.0 hours. Preferably, it is more preferably 3.5 hours.
  • the lower limit of the first time range is preferably 1.0 hours, more preferably 1.5 hours, more preferably 2.0 hours, and further preferably 2.5 hours. preferable. The same applies to the following modes of this heat treatment.
  • a second form of this heat treatment includes performing a second heat treatment (aging treatment, secondary heat treatment) on the heat treatment object after performing the first heat treatment.
  • Performing the second heat treatment includes holding the heat-treated object at a second temperature range of 20 to 1080°C. Holding the second temperature range includes holding the heat treated object for a second time range of 0.3 to 48 hours.
  • the second heat treatment is performed on the solute elements distributed within the crystal grains of the ferrite phase or at the grain boundaries. Since performing the second heat treatment includes holding at a second temperature range of 20 to 1080° C., the segregation state of solute elements within grains or at grain boundaries can be controlled. This makes it possible, for example, to reduce the segregation of the solute element or to change the segregation tendency of the solute element. As a result, the elongation of the iron casting can be further improved.
  • the upper limit of the content of Ni, which is an austenitizing element, is set to 0.6% by mass
  • the content of Cr, which is a ferritizing element is set to 16.0 to 21.0% by mass. Therefore, the ferrite phase can be stabilized from the normal temperature range to the high temperature range. Therefore, it is easy to suppress the phase transformation that accompanies the second heat treatment. Therefore, a decrease in ductility due to phase transformation can be suppressed.
  • the upper limit of the C content is set to 0.03% by mass.
  • an increase in the reprecipitation amount of Nb carbonitrides accompanying the second heat treatment can be suppressed.
  • excessive reprecipitation of Nb carbonitride in grains and grain boundaries can be suppressed. Therefore, it is possible to suppress the decrease in ductility of the iron casting and the occurrence of weld cracks.
  • the upper limit of the second temperature range is preferably 1050°C, more preferably 1000°C, more preferably 950°C, more preferably 900°C, and preferably 850°C. More preferably 800°C, more preferably 750°C, more preferably 700°C, more preferably 650°C, more preferably 600°C, more preferably 550°C and more preferably 525°C.
  • the lower limit of the second temperature range is preferably 50°C, more preferably 100°C, more preferably 150°C, more preferably 200°C, and more preferably 250°C. It is more preferably 300°C, more preferably 350°C, more preferably 400°C, more preferably 450°C, and even more preferably 475°C.
  • the upper limit of the second time range is preferably 42 hours, more preferably 36 hours, more preferably 32 hours, more preferably 24 hours, more preferably 22 hours. more preferably 20 hours, more preferably 18 hours, more preferably 16 hours, more preferably 14 hours, more preferably 12 hours, 10 hours is more preferable.
  • the lower limit of the second time range is preferably 0.5 hours, more preferably 1.0 hours, more preferably 1.5 hours, more preferably 2.0 hours. preferably 2.5 hours, more preferably 3.0 hours, more preferably 3.5 hours, more preferably 4.0 hours, 4.5 hours more preferably 5.0 hours, more preferably 5.5 hours, more preferably 6.0 hours, more preferably 6.5 hours , more preferably 7.0 hours, and even more preferably 7.5 hours.
  • this iron casting is suitable for a wide variety of applications where excellent elongation properties are required.
  • exhaust system parts exhaust manifolds, turbine housings, etc.
  • this iron casting is suitable for manufacturing cast parts for exhaust system parts.
  • this iron casting is suitable for a wide variety of applications that require complex shapes and low thermal expansion and/or high ductility to withstand high temperature strength and thermal fatigue.
  • it is also suitable for manufacturing engine parts for aircraft and ships, and boilers and turbines for thermal power generation.
  • the iron casting of the first embodiment is an iron casting obtained by subjecting a heat-treated object cast using the first form of the present material to the first form of the present heat treatment. That is, the iron casting of the first embodiment contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 1.0% by mass of Mn.
  • the iron casting of the second embodiment is an iron casting obtained by performing the first form of the present heat treatment on a heat-treated object cast using the second form of the present material. That is, the iron casting of the second embodiment contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 1.0% by mass of Mn.
  • Ni 16.0 to 21.0 wt% Cr, 0.3 to 0.8 wt% Nb, 0.0001 to 0.03 wt% N, and 0.1 to 0.3 wt% % of Ti with the balance being Fe and unavoidable elements.
  • the iron casting of the third embodiment is an iron casting obtained by performing the second form of the present heat treatment on a heat-treated object cast using the first form of the present material. That is, the iron casting of the third embodiment contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 1.0% by mass of Mn.
  • the iron casting of the fourth embodiment is an iron casting obtained by performing the second form of the present heat treatment on a heat-treated object cast using the second form of the present material. That is, the iron casting of the fourth embodiment contains 0.0001 to 0.03% by mass of C, 0.001 to 1.0% by mass of Si, and 0.001 to 1.0% by mass of Mn.
  • Ni 16.0 to 21.0 wt% Cr, 0.3 to 0.8 wt% Nb, 0.0001 to 0.03 wt% N, and 0.1 to 0.3 wt% % of Ti with the balance being Fe and unavoidable elements.
  • the "heat treatment object" in the first embodiment and the second embodiment in which the second heat treatment is not performed after the first heat treatment is "after casting, before performing the first heat treatment means "casting".
  • the “object to be heat treated” in the third embodiment and the fourth embodiment in which the second heat treatment is performed after the first heat treatment is “after casting, before performing the first heat treatment” before the first heat treatment.
  • "before the second heat treatment” means "the iron casting after the first heat treatment and before the second heat treatment”.
  • the heat-treated object may be an iron casting before machining or an iron casting after machining.
  • plastic working such as forging and rolling (hot working, cold working, etc.) was also performed. not applied.
  • FIG. 1 shows the compositions of Examples 1 to 7 in the first embodiment and Example 8 in the second embodiment, and the compositions of Comparative Examples 1 and 2.
  • FIG. 3A shows the compositions of Examples 9-43 in the third embodiment.
  • FIG. 3B shows the compositions of Examples 44-77 in the third embodiment.
  • FIG. 3C shows the compositions of Examples 78-105 and the compositions of Comparative Examples 3-5 in the fourth embodiment.
  • the content (% by mass) of each element is a value measured by emission spectrometry using an emission spectrometer "PDA-8000" manufactured by Shimadzu Corporation. is.
  • FIG. 2 shows the heat treatment conditions and mechanical properties of Examples 1 to 7 in the first embodiment and Example 8 in the second embodiment, and the heat treatment conditions and mechanical properties of Comparative Examples 1 and 2.
  • FIG. 4A shows the heat treatment conditions and mechanical properties of Examples 9 to 43 in the third embodiment.
  • FIG. 4B shows the heat treatment conditions and mechanical properties of Examples 44-77 in the third embodiment.
  • FIG. 4C shows the heat treatment conditions and mechanical properties of Examples 78-105 and the heat treatment conditions and mechanical properties of Comparative Examples 3-5 in the fourth embodiment.
  • holding temperature indicates the temperature at which the object to be heat treated is held in the heat treatment furnace (heat treatment apparatus).
  • the holding time indicates the time during which the object to be heat-treated is held while the inside of the heat-treating furnace is kept at the holding temperature.
  • the cooling method indicates a method of cooling the heat treatment object.
  • natural air cooling is a method of naturally cooling an object to be heat treated in the air without using a cooling fan or the like after taking it out of the heat treatment furnace.
  • Forced air cooling is a method of rapidly cooling the heat treatment object in air using a cooling fan or the like after it is removed from the heat treatment furnace.
  • Furnace cooling is a method of gradually cooling an object to be heat treated in a heat treatment furnace.
  • Oil cooling is a method of rapidly cooling an object to be heat treated in oil.
  • Tensile strength (MPa), 0.2% yield strength (MPa) and elongation at break (%) are values measured according to JIS Z 2241 (metal material tensile test method) for iron casting test pieces after heat treatment. .
  • As the test piece a No. 14A test piece with a diameter of 8 mm and a parallel length of 48 mm, which was taken from a Y-shaped No. B test material or a knock-off type test material cast by sand casting, was used.
  • the holding temperature of the first heat treatment in Comparative Example 1 is less than 750° C.
  • Examples 1 to 7 in the first embodiment and Example 8 in the second embodiment The holding temperature of the first heat treatment is 750° C. or higher.
  • the breaking elongation of Comparative Example 1 is 8.42%
  • the breaking elongation of Examples 1-8 is 12.03-17.95%. Therefore, in Examples 1 to 5, compared with Comparative Example 1, the elongation at break is improved by about 1.43 to 2.13 times.
  • the lower limit of the holding temperature of the first heat treatment is set to 750 ° C., and the holding time is set to 0.5 to 6.0 hours, thereby improving the breaking elongation of the iron casting. is made.
  • the holding temperature of the first heat treatment of Comparative Example 2 exceeds 1380° C., whereas the holding temperature of the first heat treatments of Examples 1 to 8 is 1380° C. or less.
  • the breaking elongation of Comparative Example 2 is 10.18%, whereas the breaking elongation of Examples 1-8 is 12.03-17.95%. Therefore, in Examples 1 to 8, compared with Comparative Example 2, the elongation at break is improved by about 1.18 to 1.76 times.
  • the upper limit of the holding temperature of the first heat treatment was set to 1380 ° C., and the holding time was set to 0.5 to 6.0 hours, thereby improving the breaking elongation of the iron casting. is made.
  • Examples 9-105 and Examples 1-8) As shown in FIGS. 2, 4A, 4B and 4C, in Examples 1 to 8, the second heat treatment is not performed after the first heat treatment (see FIG. 2), whereas in the third embodiment In Examples 9 to 77 and Examples 78 to 105 in the fourth embodiment, the second heat treatment was performed after the first heat treatment (see FIGS. 4A, 4B and 4C).
  • the holding temperature for the second heat treatment of Examples 9-105 is 20-1080° C. and the holding time is 0.3-48 hours.
  • the elongation at break of Examples 1-8 is 12.03-17.95%
  • the elongation at break of Examples 9-77 is 18.50-38.95%.
  • Examples 9 to 77 the breaking elongation is improved by a maximum of about 3.24 times (minimum of about 1.04 times) as compared with Examples 1 to 8.
  • the holding temperature of the second heat treatment is 20 to 1080 ° C. and the holding time is 0.3 to 48 hours, thereby further improving the breaking elongation of the iron casting. is made.
  • Comparative Example 3 has an S content of 0.029% by mass, while Examples 9 to 77 have an upper limit of S content of 0.027%. % by mass.
  • the breaking elongation of Comparative Example 3 is 8.85%, while the breaking elongation of Examples 9-77 is 18.50-29.75%. . Therefore, in Examples 9 to 77, compared with Comparative Example 3, the breaking elongation is improved by about 2.09 to 3.36 times.
  • the breaking elongation of iron castings can be improved.
  • Comparative Example 4 and Examples 9 to 77 are common in that they do not contain Ti.
  • the holding temperature of the second heat treatment of Comparative Example 4 exceeds 1080° C.
  • the holding temperature of the second heat treatments of Examples 9 to 77 is below 1080°C.
  • the breaking elongation of Comparative Example 4 is 9.88%
  • the breaking elongation of Examples 9-77 is 18.50-29.75%. Therefore, in Examples 9 to 77, compared with Comparative Example 4, the elongation at break is improved by about 1.87 to 3.01 times.
  • the breaking elongation of iron castings can be improved by setting the upper limit of the holding temperature of the second heat treatment to 1080 ° C. and setting the holding time to 0.3 to 48 hours. ing.
  • Examples 9 to 77 do not contain Ti, whereas Examples 78 to 105 contain 0.1 to 0.3% by mass of Ti. I have to.
  • the holding temperature of the second heat treatment of Examples 9 to 77 and Examples 78 to 105 are all 20 to 1080 ° C., and the holding time is 0.3 to 1080 ° C. They are common in that they are 48 hours.
  • the elongation at break of Examples 9-77 is 18.50-29.75%
  • the elongation at break of Examples 78-105 is 21.98-38.95%.
  • Examples 78 to 105 the maximum breaking elongation is improved by about 1.31 times and the minimum breaking elongation is improved by about 1.19 times as compared with Examples 9 to 77.
  • the Ti content was 0.1 to 0.3% by mass
  • the holding temperature of the second heat treatment was 20 to 1080° C.
  • the holding time was 0.3 to 48 hours.
  • One aspect of the method for manufacturing the iron casting of the above embodiment is to cast a heat treatment target using a ferritic casting material, and after casting the heat treatment target, the first and performing a heat treatment of Another aspect of the method of manufacturing the iron casting of the above embodiment is to cast the heat-treated object using a ferritic casting material, and after casting the heat-treated object, the heat-treated object is subjected to the first and performing a second heat treatment on the heat-treated object after performing the first heat treatment.
  • Performing the first heat treatment includes holding the heat-treated object in a first temperature range of 750 to 1380.degree.
  • Holding the first temperature range includes holding the heat-treated object for a first time range of 0.5 to 6.0 hours.
  • Performing the second heat treatment includes holding the heat-treated object at a second temperature range of 20 to 1080°C.
  • Holding the second temperature range includes holding the heat treated object for a second time range of 0.3 to 48 hours.

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0533105A (ja) * 1991-07-31 1993-02-09 Daido Steel Co Ltd フエライト系耐熱鋳鋼
JPH08225898A (ja) * 1995-02-17 1996-09-03 Daido Steel Co Ltd 耐熱鋳鋼
CN105063496A (zh) * 2015-09-02 2015-11-18 祁同刚 一种铁素体不锈钢及其制造工艺
JP2016509629A (ja) * 2013-01-09 2016-03-31 ザ・ナノスティール・カンパニー・インコーポレーテッド 管状製品用の新しいクラスの鋼

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4500351A (en) * 1984-02-27 1985-02-19 Amax Inc. Cast duplex stainless steel
JP3001718B2 (ja) * 1992-04-17 2000-01-24 新日本製鐵株式会社 フェライト系ステンレス鋼薄肉鋳片の製造方法
EP3243920B1 (de) * 2017-03-24 2020-04-29 GF Casting Solutions Kunshan Co. Ltd. Sphärogusslegierung

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0533105A (ja) * 1991-07-31 1993-02-09 Daido Steel Co Ltd フエライト系耐熱鋳鋼
JPH08225898A (ja) * 1995-02-17 1996-09-03 Daido Steel Co Ltd 耐熱鋳鋼
JP2016509629A (ja) * 2013-01-09 2016-03-31 ザ・ナノスティール・カンパニー・インコーポレーテッド 管状製品用の新しいクラスの鋼
CN105063496A (zh) * 2015-09-02 2015-11-18 祁同刚 一种铁素体不锈钢及其制造工艺

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