CN114959508B - Stainless steel and preparation method thereof - Google Patents

Stainless steel and preparation method thereof Download PDF

Info

Publication number
CN114959508B
CN114959508B CN202210900252.4A CN202210900252A CN114959508B CN 114959508 B CN114959508 B CN 114959508B CN 202210900252 A CN202210900252 A CN 202210900252A CN 114959508 B CN114959508 B CN 114959508B
Authority
CN
China
Prior art keywords
stainless steel
temperature
aging treatment
ferrite
strength
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210900252.4A
Other languages
Chinese (zh)
Other versions
CN114959508A (en
Inventor
董超芳
王力
孔德成
敖敏
贺星
纪毓成
查力强
李晓刚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Science and Technology Beijing USTB
Original Assignee
University of Science and Technology Beijing USTB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Science and Technology Beijing USTB filed Critical University of Science and Technology Beijing USTB
Priority to CN202210900252.4A priority Critical patent/CN114959508B/en
Publication of CN114959508A publication Critical patent/CN114959508A/en
Application granted granted Critical
Publication of CN114959508B publication Critical patent/CN114959508B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/06—Metallic powder characterised by the shape of the particles
    • B22F1/065—Spherical particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/28—Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/60—Treatment of workpieces or articles after build-up
    • B22F10/64—Treatment of workpieces or articles after build-up by thermal means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
    • B33Y40/20—Post-treatment, e.g. curing, coating or polishing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y70/00—Materials specially adapted for additive manufacturing
    • 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
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • 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
    • C21D6/02—Hardening by precipitation
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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
    • 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
    • C21D2211/008—Martensite
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Nanotechnology (AREA)
  • Plasma & Fusion (AREA)
  • Heat Treatment Of Articles (AREA)

Abstract

The invention belongs to the technical field of additive manufacturing metal materials, in particular to a high-strength, high-toughness and high-corrosion-resistance stainless steel manufactured by an additive with an adjustable structure and a preparation method thereof, wherein alloy components are optimized to a ferrite martensite phase region interface meeting a phase diagram of the relationship between the alloy components and phases of the stainless steel manufactured by the additive, a microstructure after printing is mainly a large-size ferrite phase, and a nano-scale precipitated phase can be formed in the ferrite matrix by adopting direct aging treatment, so that the strength of the alloy manufactured by the additive is obviously improved; meanwhile, the ferrite matrix generates obvious deformation twin crystals in the stretching process, and the plasticity and toughness of the ferrite matrix are improved. In addition, solid solution and aging treatment are adopted, and the regulation and control of the ferrite-martensite stainless steel with different proportions are realized by adjusting the solid solution temperature. The stainless steel can realize corrosion resistance obviously superior to that of the traditional forged martensitic stainless steel, finally, the high-strength, high-toughness and high-corrosion-resistance stainless steel with multiple phase distribution is prepared by regulation, and a new idea is provided for preparing the high-performance stainless steel with the adjustable microstructure by means of additive manufacturing.

Description

Stainless steel and preparation method thereof
Technical Field
The invention relates to the technical field of additive manufacturing of metal materials, in particular to high-strength, high-toughness and high-corrosion-resistance stainless steel with adjustable and controllable structures and a preparation method thereof.
Background
With the rapid development of aerospace and ocean engineering, the service load and environment of high-performance high-strength stainless steel gradually diversify. The service performance of the high-strength martensitic stainless steel is closely related to the microstructure, and the higher strength of the high-strength martensitic stainless steel is mainly derived from ultrahigh-density dislocation and a nano-scale precipitated phase of a matrix. The plasticity and toughness of the steel are continuously optimized mainly by improving the distribution and the content of austenite. However, an increase in either strength or plasticity results in a decrease in the other property, known as the strong plasticity inversion contradiction. Therefore, the multiphase microstructure needs to be optimized and regulated by a novel preparation process, so that the toughness and the corrosion resistance of the composite material are further regulated and controlled, and the requirements under different service loads and environments are met.
As a new technology rapidly developed in recent years, the additive manufacturing (also called 3D printing) technology can rapidly and accurately manufacture a complex structural member, simplify the process, save materials, greatly shorten the material development period, and realize the manufacture of a complex structure which is difficult or impossible to process by the conventional technology. The additive manufacturing has the characteristics of high laser energy, rapid cooling, multi-pass circulating heat treatment and the like, so that the additive manufacturing stainless steel has an obvious molten pool structure, and the prepared structural part has the characteristics of uneven stress distribution, multiple interfaces, fine tissues and the like.
The high-strength stainless steel after being printed at present has a fine microstructure, nano-scale oxide inclusion and an obvious molten pool interface in part. Tensile experiments show that the mechanical property of the stainless steel can be compared favorably with that of the traditional martensitic stainless steel. Meanwhile, the distribution of the microstructure phase is obviously different from that of the martensitic stainless steel with the same composition in the traditional preparation process. Therefore, the correlation needs to be established for chemical components and microstructures of the high-strength stainless steel in the additive manufacturing process, and the microstructures and phase distribution of the high-strength stainless steel are regulated and controlled by means of post-heat treatment, so that the novel controllable high-strength high-corrosion-resistance stainless steel with multiple phase contents is finally prepared.
Disclosure of Invention
The invention mainly aims to provide a high-strength, high-toughness and high-corrosion-resistance stainless steel manufactured by using an additive with adjustable and controllable structure and a preparation method thereof. The high-strength, high-toughness and high-corrosion-resistance stainless steel with the adjustable and controllable structure can realize multi-stage strong plasticity matching and better corrosion resistance. Provides a choice for parts with complex requirements on bearing and corrosion resistance under different service environments.
To solve the above technical problem, according to an aspect of the present invention, the present invention provides the following technical solutions:
a stainless steel comprises, by weight, not more than 0.05% C, not more than 1% Si, not more than 1% Mn, 14.5-15.5% Cr, 5.0-5.5% Ni, 3.5-4.5% Cu, 0.35-0.45% Nb, 2-3% Mo, and the balance Fe and unavoidable impurities,
and Cr equivalent Cr eq =%Cr+%Mo+2.2%Ti+0.7%Nb+2.48%Al，
Ni equivalent of Ni eq =%Ni+35%C+20%N+0.25%Cu，
The stainless steel is a high-strength and high-toughness high-corrosion-resistance stainless steel manufactured by an additive with an adjustable tissue, the yield strength regulating range is 600-1100MPa, the tensile strength regulating range is 1050-1250MPa, the elongation after fracture regulating range is 10-26%, and the pitting potential is 420-500mV in a 0.1MNaCl solution simulating an atmospheric environment.
The high-toughness high-corrosion-resistance stainless steel is manufactured by the additive manufacturing with the adjustable and controllable structure, and the microstructure after printing is mainly a large-size ferrite phase; by adopting direct aging treatment, a nanoscale precipitated phase can be formed in a ferrite matrix, and the strength of the additive manufacturing alloy is obviously improved; meanwhile, the ferrite matrix generates obvious deformation twin crystals in the stretching process, so that the plasticity and toughness of the ferrite matrix are improved; in addition, solid solution and aging treatment are adopted, and the regulation and control of ferrite-martensite stainless steel with different proportions are realized by adjusting the solid solution temperature, so that the stainless steel can realize corrosion resistance obviously superior to the traditional forged martensite stainless steel, and finally the high-strength, high-toughness and high-corrosion-resistance stainless steel with multi-phase distribution is prepared by regulation and control.
As a preferable embodiment of the stainless steel of the present invention, wherein: the high-strength, high-toughness and high-corrosion-resistance stainless steel with multi-phase distribution comprises ferrite + precipitated phase stainless steel, martensite + precipitated phase stainless steel and ferrite + martensite + precipitated phase stainless steel.
As a preferable embodiment of the stainless steel of the present invention, wherein: the Cr equivalent Cr eq From 16.47 to 18.11, the Ni equivalent being Ni eq Is 6.07-7.69. More preferably, the Cr equivalent Cr eq From 17.55 to 18.11, the Ni equivalent being Ni eq Is 6.35-6.56.
As a preferable embodiment of the stainless steel of the present invention, wherein: the yield strength regulating range of the high-strength and high-toughness and high-corrosion-resistance stainless steel manufactured by the tissue-controllable additive is 700-1050MPa, the tensile strength regulating range is 1070-1220MPa, the elongation after fracture regulating range is 12-26%, and the pitting potential is 440-490mV in a 0.1MNaCl solution simulating an atmospheric environment.
In order to solve the above technical problem, according to another aspect of the present invention, the present invention provides the following technical solutions:
a method for preparing stainless steel comprises the following steps:
s1, preparing stainless steel powder with the components;
s2, printing the powder obtained in the step S1 by adopting a 3D printing process to form a printed product;
and S3, carrying out heat treatment on the printed product formed in the step S2.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S1, the particle size of the powder is 15-53 μm.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S2, the parameters of the 3D printing process are: the diameter of the light spot is 100-300 μm, the scanning power is 230-400W, the scanning interval is 0.07-0.10mm, the scanning speed is 600-800mm/s, and the thickness of the powder layer is 0.015-0.03mm; the preheating temperature of the substrate is 60-100 ℃, and the rotation angle of the optical path between layers is 67 ℃.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S3, the heat treatment is different process heat treatments, including aging treatment, high-temperature solution treatment and aging treatment.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S3, the heating rate of the heat treatment is 6-10 ℃ per minute.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S3, the aging treatment is single-pass or multi-pass aging treatment; the temperature of the single-pass aging treatment is 450-520 ℃, and the temperature is kept for 2-10h; the multi-pass aging treatment process comprises the following steps: the first time of aging treatment is carried out for heat preservation for 4-6h at the temperature of 510-520 ℃; the second time aging treatment is carried out for 4 to 12 hours at the temperature of 450 to 490 ℃.
As a preferable embodiment of the method for producing a stainless steel according to the present invention, wherein: in the step S3, the temperature of the high-temperature solution treatment is 1050-1200 ℃, and the temperature is kept for 0.5-2h.
The invention has the following beneficial effects:
the invention provides a high-strength, high-toughness and high-corrosion-resistance stainless steel manufactured by an additive material and a preparation method thereof, wherein alloy components are optimized to meet the requirement of a ferrite martensite phase region interface of a phase composition diagram of alloy components and phases of the stainless steel manufactured by the additive material, a microstructure after printing is mainly a large-size ferrite phase, and a nano-scale precipitated phase can be formed in a ferrite matrix by adopting direct aging treatment, so that the strength of the alloy manufactured by the additive material is obviously improved; meanwhile, the ferrite matrix generates obvious deformation twin crystals in the stretching process, and the plasticity and toughness of the ferrite matrix are improved. In addition, solid solution and aging treatment are adopted, the regulation and control of the ferrite-martensite stainless steel with different proportions are realized by adjusting the solid solution temperature, and finally the multi-phase distribution high-strength-toughness and high-corrosion-resistance stainless steel is prepared by regulation and control, so that a new idea is provided for manufacturing the high-performance stainless steel with adjustable microstructure by means of additive manufacturing.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a diagram of the composition of a stainless steel phase of the present invention as a function of Cr equivalent and Ni equivalent;
FIG. 2 is a microstructure of a stainless steel according to example 1 of the present invention;
FIG. 3 is a microstructure of a stainless steel according to example 3 of the present invention;
FIG. 4 shows the results of room temperature tensile testing of stainless steel according to various embodiments of the present invention;
FIG. 5 shows the results of electrochemical corrosion tests on stainless steels according to some examples of the present invention and comparative examples.
The implementation, functional features and advantages of the present invention will be further described with reference to the accompanying drawings.
Detailed Description
The following will clearly and completely describe the technical solutions in the embodiments, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a high-strength, high-toughness and high-corrosion-resistance stainless steel manufactured by an additive manufacturing method and a preparation method thereof, wherein the alloy components are optimized to meet the ferrite martensite phase region interface of a phase diagram of the relation between the alloy components and the phase components of the stainless steel manufactured by the additive manufacturing method, and compared with the traditional martensite stainless steel material with similar components, the phase components can be adjusted and controlled, and meanwhile, the stainless steel has high strength, plasticity and high corrosion resistance. The microstructure matrix after printing is mainly ferrite, and the microstructure can be converted into a ferrite + precipitated phase, a martensite + precipitated phase, and a ferrite + martensite + precipitated phase after being regulated and controlled by different heat treatment processes. The yield strength regulating range is 600-1100MPa, the tensile strength regulating range is 1050-1250MPa, the strength can be comparable to that of a traditional forging sample with similar components, and the yield ratio is larger. The regulation and control range of the elongation after fracture is 10-26%, and higher plasticity can be realized under the condition of ensuring the strength. The pitting potential is 420-500mV in a 0.1MNaCl solution simulating the atmospheric environment, the electrochemical resistance value is larger, and the corrosion resistance is far superior to that of the traditional forged martensitic stainless steel.
According to one aspect of the invention, the invention provides the following technical scheme:
a stainless steel comprises, by weight, not more than 0.05% C, not more than 1% Si, not more than 1% Mn, 14.5-15.5% Cr, 5.0-5.5% Ni, 3.5-4.5% Cu, 0.35-0.45% Nb, 2-3% Mo, and the balance Fe and unavoidable impurities,
and Cr equivalent Cr eq =%Cr+%Mo+2.2%Ti+0.7%Nb+2.48%Al，
Ni equivalent of Ni eq =%Ni+35%C+20%N+0.25%Cu，
The Cr equivalent Cr eq From 16.47 to 18.11, the Ni equivalent being Ni eq Is 6.07-7.69. Preferably, the Cr equivalent Cr eq From 17.55 to 18.11, said Ni equivalent being Ni eq Is 6.35-6.56.
Specifically, the Cr equivalent Cr eq For example, but not limited to, a range between any one or two of 16.5, 16.6, 16.7, 16.8, 16.9, 17.0, 17.1, 17.2, 17.3, 17.4, 17.5, 17.6, 17.7, 17.8, 17.9, 18.0, 18.1; in particular, the Ni equivalent Ni eq For example, but not limited to, any one of 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6 or a range between any two.
The invention utilizes the principle of the difference of the microstructure of the additive manufacturing stainless steel and the microstructure of the traditional casting stainless steel, designs the alloy components to be the martensite structure of the traditional manufacturing, and simultaneously locates at the interface of the ferrite martensite phase region of the phase diagram of the additive manufacturing stainless steel so as to obtain the stainless steel with different phase compositions from the traditional manufacturing.
The stainless steel is high-strength and high-toughness high-corrosion-resistance stainless steel manufactured by an additive with an adjustable structure, the yield strength regulating range is 600-1100MPa, the tensile strength regulating range is 1050-1250MPa, the elongation after fracture regulating range is 10-26%, and the pitting potential is 420-500mV in a 0.1MNaCl solution simulating an atmospheric environment.
Preferably, the yield strength regulating range of the tissue-controllable additive manufacturing high-strength and high-toughness and high-corrosion-resistance stainless steel is 700-1050MPa, the tensile strength regulating range is 1070-1220MPa, the elongation after fracture regulating range is 12-26%, and the pitting potential is 440-490mV in a 0.1M NaCl solution simulating an atmospheric environment.
According to another aspect of the invention, the invention provides the following technical scheme:
a preparation method of stainless steel comprises the following steps:
s1, preparing stainless steel powder with the components;
s2, printing the powder obtained in the step S1 by adopting a 3D printing process to form a printed product;
and S3, carrying out heat treatment on the printed product formed in the step S2.
The ferrite matrix stainless steel with good plasticity and toughness is prepared by optimizing alloy components and utilizing the characteristic of the rapid cooling process of additive manufacturing, and then the ferrite-martensite stainless steel with multiple phase distribution is prepared by regulating and controlling heat treatment. The microscopic structure after printing is mainly a large-size ferrite phase; by adopting direct aging treatment, a nanoscale precipitated phase can be formed in a ferrite matrix, and the strength of the additive manufacturing alloy is obviously improved; meanwhile, the ferrite matrix generates obvious deformation twin crystals in the stretching process, so that the plasticity and toughness of the ferrite matrix are improved; in addition, solid solution and aging treatment are adopted, the regulation and control of ferrite-martensite stainless steel with different proportions are realized by adjusting the solid solution temperature, and finally the multi-phase distributed high-strength high-toughness high-corrosion-resistance stainless steel is prepared by regulation and control.
In the step S1, the particle size of the powder is 15 to 53 μm, specifically, the particle size of the powder is, for example, but not limited to, a range between any two of 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, and 53 μm; the powder is free of hollow powder, the sphericity is over 95%, no inclusion is detected, and the oxygen content is less than 0.06%.
In step S2, parameters of the 3D printing process may be adjusted according to the particle size and composition of the raw material to be printed, and may be, for example: the diameter of the light spot is 100-300 μm, the scanning power is 230-400W, the scanning interval is 0.07-0.10mm, the scanning speed is 600-800mm/s, and the thickness of the powder layer is 0.015-0.03mm; the preheating temperature of the substrate is 60-100 ℃, and the rotation angle of an interlayer optical path is 67 degrees; specifically, the spot diameter is, for example, but not limited to, any one of 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, or a range between any two; the scan power is, for example, but not limited to, any one of 230W, 250W, 300W, 400W, or a range between any two; the scan pitch is, for example, but not limited to, any one of 0.07mm, 0.08mm, 0.09mm, 0.10mm, or a range between any two; the scanning speed is, for example, but not limited to, 600mm/s, 650mm/s, 700mm/s, 750mm/s, 800mm/s, or a range between any two; the powder layer thickness is, for example, but not limited to, any one of 0.015mm, 0.02mm, 0.025mm, 0.03mm or a range between any two; the substrate preheating temperature is, for example, but not limited to, any one of 60 ℃, 70 ℃, 80 ℃, 90 ℃ and 100 ℃ or a range between any two of them.
In the step S3, the heat treatment is different process heat treatments, including aging treatment, high-temperature solution treatment and aging treatment. The heating rate of the heat treatment is 6-10 ℃ per min, and specifically, the heating rate of the heat treatment is, for example, but not limited to, any one of 6 ℃, 7 ℃, 8 ℃, 9 ℃ and 10 ℃ per min or a range between any two of the two; the aging treatment is single-pass or multi-pass aging treatment; the temperature of the single-pass aging treatment is 450-520 ℃, and the heat is preserved for 2-10h; specifically, the temperature of the single-pass aging treatment is, for example and without limitation, 450 ℃, 460 ℃, 470 ℃, 480 ℃, 490 ℃, 500 ℃, 510 ℃, 520 ℃, or any range therebetween, and the heat preservation time is, for example and without limitation, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, or 10h, or any range therebetween; the multi-pass aging treatment process comprises the following steps: the first time of aging treatment is carried out for heat preservation for 4-6h at the temperature of 510-520 ℃; the second time aging treatment is carried out for 4-12h at the temperature of 450-490 ℃. Specifically, the temperature of the first secondary aging treatment is, for example, but not limited to, any one of 510 ℃, 511 ℃, 512 ℃, 513 ℃, 514 ℃, 515 ℃, 516 ℃, 517 ℃, 518 ℃, 519 ℃, 520 ℃, or a range between any two of the above, and the heat preservation time is, for example, but not limited to, any one of 4h, 4.5h, 5h, 5.5h, and 6h, or a range between any two of the above; the temperature of the second-pass aging treatment is, for example and without limitation, 450 ℃, 460 ℃, 470 ℃, 480 ℃, 490 ℃, or any one or any two ranges, and the heat preservation time is, for example and without limitation, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h or any one or any two ranges; the temperature of the high-temperature solution treatment is 1050-1200 ℃, and the temperature is kept for 0.5-2h; specifically, the temperature of the high-temperature solution treatment is within the range of any one or any two of 1050 ℃, 1060 ℃, 1070 ℃, 1080 ℃, 1090 ℃, 1100 ℃, 1110 ℃, 1120 ℃, 1130 ℃, 1140 ℃, 1150 ℃, 1160 ℃, 1170 ℃, 1180 ℃, 1190 ℃ and 1200 ℃, and the heat preservation time is within the range of any one or any two of 0.5h, 1h, 1.5h and 2h.
The technical solution of the present invention is further illustrated by the following specific examples.
Example 1
A high-strength, high-toughness and high-corrosion-resistance stainless steel manufactured by an additive material with adjustable and controllable structure adopts the following preparation method:
s1, preparing stainless steel powder for later use;
the powder components comprise 0.004 wt% of C, 0.084 wt% of Si, 0.1 wt% of Mn, 14.97 wt% of Cr, 5.21 wt% of Ni, 3.94 wt% of Cu, 0.39 wt% of Nb, 2.54wt% of Mo, and the balance of Fe and inevitable impurities. The powder has a particle size of 15-53 μm, no hollow powder, a sphericity of more than 95%, no micron-sized inclusion detected, and an oxygen content of 0.057 wt%.
S2, printing the powder obtained in the step S1 by adopting a 3D printing process to form a printed product;
the spot diameter of the 3D printing process is 100 mu m, the scanning power is 230W, the scanning interval is 0.10mm, the scanning speed is 800mm/s, the powder layer thickness is 0.02mm, the substrate preheating temperature is 80 ℃, the interlayer light path rotation angle is 67 degrees, and the sample density after printing is 98.5 percent;
and S3, carrying out heat treatment on the printed product formed in the step S2.
The heat treatment is carried out in a muffle furnace, single-pass aging treatment is carried out, the temperature rise rate is controlled to be 8 ℃ per minute, the aging temperature is 480 ℃, and heat preservation is carried out for 4 hours.
Example 2
Example 2 is identical to example 1 in powder composition and heat treatment process, except for the printing process.
The difference in the printing process of example 2 is that the scan speed was 600mm/s and the density of the prepared sample was 99.2%.
Example 3
Example 3 is identical to example 1 in powder composition and printing process, except for the heat treatment process.
Example 3 heat treatment was performed by a high-temperature solution treatment plus single-pass aging treatment process; controlling the heating rate to be 8 ℃ per min, the high-temperature solid solution temperature to be 1050 ℃, the solid solution time to be 1h, the single-pass aging temperature to be 480 ℃, and the heat preservation time to be 4h.
Example 4
Example 4 is identical to example 1 in powder composition and printing process, except for the heat treatment process.
Example 4 heat treatment was carried out by solution treatment and double secondary aging treatment; controlling the heating rate to be 8 ℃/min, the solid solution temperature to be 1050 ℃ and the solid solution time to be 1h; the first aging temperature is 510 ℃, and the heat preservation is carried out for 4 hours; the aging temperature of the second time is 480 ℃, and the temperature is kept for 4h.
Comparative example 1
The printing process and the heat treatment process are exactly the same as those of example 1, except that the powder component does not contain Mo element in the alloy system.
FIG. 1 shows additive manufacturing of Cr in stainless steel eq /Ni eq Statistics of equivalent weight versus phase composition. From this, it is understood that Cr is contained in the alloy composition of example 1 of the present invention eq Equivalent weight of 17.783,Ni eq The equivalent weight is 6.435,435,Cr eq /Ni eq The equivalent is located at the additive manufacturing ferrite martensite phase interface.
FIGS. 2-3 show the microstructure results of examples 1 and 3, from which it can be seen that the microstructure matrix of example 1 was ferrite after direct aging treatment after printing; in example 3, solid solution and aging treatment are performed after printing, and the microstructure matrix is martensite, so that the microstructure of the matrix is regulated and controlled.
FIG. 4 shows the results of room temperature tensile testing of stainless steel of example 1,2,3,4. As can be seen from FIG. 4, the tensile strength of the steel in examples 1 and 2 is 1066-1069 MPa, the elongation after fracture is 26-26.5%, and the plasticity is much higher than that of the traditional high-strength stainless steel. The martensite matrix is adopted in the embodiments 3 and 4, the tensile strength can reach 1220-1230 MPa, and the martensite matrix can be compared with the traditional high-strength stainless steel.
FIG. 5 shows the results of electrochemical corrosion tests on stainless steels of example 1,3,4 and comparative example 1, wherein (a) in FIG. 5 is the polarization curve and (b) in FIG. 5 is the electrochemical impedance spectrum, and it can be seen from FIG. 5 that the pitting potential of the polarization curve is much higher than that of comparative example 1, about 420-500mV, the electrochemical impedance value is larger, and the corrosion resistance is much better than that of comparative example 1 and the conventional forged martensitic stainless steel.
In conclusion, the invention can realize the regulation and control of matrix tissues (ferrite and martensite), thereby realizing the comprehensive regulation and control of strong plasticity and achieving higher strength and super-good plasticity. Meanwhile, the invention can realize higher corrosion resistance. Finally, the excellent comprehensive service performance of the material is realized.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the present specification and directly/indirectly applied to other related technical fields within the spirit of the present invention are included in the scope of the present invention.

Claims (9)

1. A stainless steel is characterized by comprising, by weight, not more than 0.05% C, not more than 1% Si, not more than 1% Mn, 14.5-15.5% Cr, 5.0-5.5% Ni, 3.5-4.5% Cu, 0.35-0.45% Nb, 2-3% Mo, and the balance Fe and unavoidable impurities,
and Cr equivalent Cr eq =%Cr+%Mo+2.2%Ti+0.7%Nb+2.48%Al，Cr eq 16.47-18.11;
ni equivalent of Ni eq =%Ni+35%C+20%N+0.25%Cu，Ni eq 6.07-7.69;
the yield strength regulating range of the stainless steel is 600-1100MPa, the tensile strength regulating range is 1050-1250MPa, the elongation after fracture regulating range is 10-26%, and pitting potential is 420-500mV in a 0.1MNaCl solution simulating an atmospheric environment.
2. The stainless steel according to claim 1, wherein the stainless steel is a high-toughness and high-corrosion-resistance stainless steel manufactured by an additive manufacturing method with a controllable structure, the controllable structure means that a microstructure of the stainless steel after printing is a ferrite phase, and a microstructure of the stainless steel after heat treatment is ferrite-martensite with multiple phase distribution.
3. A stainless steel according to any of claims 1-2, characterized in that the yield strength of the stainless steel is regulated in the range of 700-1050MPa, the tensile strength is regulated in the range of 1070-1220MPa, the elongation after fracture is regulated in the range of 12-26%, and the pitting potential is realized in a 0.1m naci solution simulating an atmospheric environment in the range of 440-490mV.
4. A method of making the stainless steel of claim 1, comprising the steps of:
s1, preparing powder of the stainless steel with the composition of claim 1;
s2, printing the powder obtained in the step S1 by adopting a 3D printing process to form a printed product;
and S3, carrying out heat treatment on the printed product formed in the step S2.
5. The method for producing stainless steel according to claim 4, wherein in step S1, the powder has a particle size of 15 to 53 μm.
6. The method for preparing stainless steel according to claim 4, wherein in the step S2, the parameters of the 3D printing process are as follows: the diameter of the light spot is 100-300 μm, the scanning power is 230-400W, the scanning interval is 0.07-0.10mm, the scanning speed is 600-800mm/s, and the thickness of the powder layer is 0.015-0.03mm; the preheating temperature of the substrate is 60-100 ℃, and the rotation angle of the optical path between layers is 67 ℃.
7. The method for preparing stainless steel according to claim 4, wherein in the step S3, the heat treatment is different process heat treatment, including aging treatment, high temperature solution treatment + aging treatment; the heating rate of the heat treatment is 6-10 ℃/min.
8. The method for preparing stainless steel according to claim 7, wherein in the step S3, the aging treatment is a single-pass or multi-pass aging treatment; the temperature of the single-pass aging treatment is 450-520 ℃, and the temperature is kept for 2-10h; the multi-pass aging treatment process comprises the following steps: the first time of aging treatment is carried out for heat preservation for 4-6h at the temperature of 510-520 ℃; the second time aging treatment is carried out for 4-12h at the temperature of 450-490 ℃.
9. The method for preparing stainless steel according to claim 7 or 8, wherein the temperature of the high-temperature solution treatment in the step S3 is 1050-1200 ℃, and the temperature is kept for 0.5-2h.
CN202210900252.4A 2022-07-28 2022-07-28 Stainless steel and preparation method thereof Active CN114959508B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210900252.4A CN114959508B (en) 2022-07-28 2022-07-28 Stainless steel and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210900252.4A CN114959508B (en) 2022-07-28 2022-07-28 Stainless steel and preparation method thereof

Publications (2)

Publication Number Publication Date
CN114959508A CN114959508A (en) 2022-08-30
CN114959508B true CN114959508B (en) 2022-10-21

Family

ID=82969746

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210900252.4A Active CN114959508B (en) 2022-07-28 2022-07-28 Stainless steel and preparation method thereof

Country Status (1)

Country Link
CN (1) CN114959508B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115110008B (en) * 2022-08-31 2022-11-08 北京科技大学 Pitting corrosion resistant martensitic hardened stainless steel

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101210304A (en) * 2006-12-27 2008-07-02 沈阳鼓风机(集团)有限公司 Martensite precipitation hardening stainless steel for compressor impeller and preparation method thereof
CN101532110B (en) * 2008-09-17 2010-06-02 中国科学院金属研究所 Method for removing Delta ferrite from high strength and toughness martensitic stainless steel
JP2016160454A (en) * 2015-02-27 2016-09-05 日本シリコロイ工業株式会社 Laser sinter laminate method, heat treatment method, metal powder and molded article
ES2848378T3 (en) * 2016-12-07 2021-08-09 Hoeganaes Ab Publ Stainless steel powder to produce sintered duplex stainless steel
CN111519113B (en) * 2020-05-21 2021-10-29 北京科技大学 High-strength stainless steel powder for electronic products and preparation process
US20220081745A1 (en) * 2020-09-11 2022-03-17 Questek Innovations Llc Stainless steel powders for additive manufacturing

Also Published As

Publication number Publication date
CN114959508A (en) 2022-08-30

Similar Documents

Publication Publication Date Title
CN110273095A (en) A kind of preparation method of tensile strength 1.5GPa medium entropy alloy
CN111826550B (en) Moderate-strength nitric acid corrosion resistant titanium alloy
CN114086049B (en) 2.0GPa grade CoCrNi-based medium entropy alloy with ultrahigh yield strength and plasticity and preparation method thereof
CN112063945B (en) Improve Ti2Heat treatment process for lasting and creep property of AlNb-based alloy
CN101538686A (en) Martensite precipitation hardening stainless steel for structural member and manufacturing method thereof
CN110484826B (en) 05Cr17Ni4Cu4Nb martensitic stainless steel and heat treatment process thereof
CN112301255B (en) High-thermal-conductivity and high-strength Co-Fe-Ni alloy for die and additive manufacturing method thereof
CN110218948A (en) A kind of low-density high tenacity steel and preparation method thereof
CN104561657A (en) Titanium-aluminium alloy material and preparation technology thereof
CN114959508B (en) Stainless steel and preparation method thereof
CN108384928B (en) A method of accelerating nanometer bainitic transformation
CN114395714A (en) Ultrahigh-strength Co-based medium-entropy alloy and preparation method thereof
CN114855092B (en) High-strength and high-toughness stainless steel manufactured by additive manufacturing and preparation process thereof
CN111926260B (en) Preparation method of low-magnetism stainless steel medium plate with yield strength of 785MPa
CN113832369A (en) Metastable beta titanium alloy with ultrahigh yield strength and high plasticity manufactured by additive manufacturing
CN113523282A (en) Method for preparing fine isometric crystal titanium alloy through 3D printing
CN113862499A (en) Processing and manufacturing method of novel titanium-based composite material with two-state tissue
KR102286610B1 (en) High entropy alloy having nanoscale compositionally modulated layered structure and method for manufacturing the same
CN113249630A (en) Forging and pressing process of high-entropy alloy
CN114086086B (en) Nano-phase carbon-nitrogen composite particle reinforced invar alloy wire and preparation method thereof
CN108913943A (en) Tough titanium alloy of a kind of nearly α phase height and preparation method thereof
CN114134368B (en) High-temperature alloy for laser cutting nozzle and preparation method thereof
CN112853222A (en) 06Cr18Ni11Ti austenitic stainless steel and preparation method thereof
CN111893277A (en) Manufacturing method for obtaining dispersed carbide in medium-entropy high-speed steel structure
CN114318150B (en) High-temperature-resistant bolt and production process thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
CB03 Change of inventor or designer information
CB03 Change of inventor or designer information

Inventor after: Dong Chaofang

Inventor after: Wang Li

Inventor after: Kong Decheng

Inventor after: Ao Min

Inventor after: He Xing

Inventor after: Ji Yucheng

Inventor after: Zha Liqiang

Inventor after: Li Xiaogang

Inventor before: Dong Chaofang

Inventor before: Wang Li

Inventor before: Kong Decheng

Inventor before: Ao Min

Inventor before: He Xing

Inventor before: Ji Yucheng

Inventor before: Zha Liqiang

Inventor before: Li Xiaogang

GR01 Patent grant
GR01 Patent grant