CN117305726A - Heat-corrosion-resistant steel alloy and preparation method and application thereof - Google Patents

Heat-corrosion-resistant steel alloy and preparation method and application thereof Download PDF

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CN117305726A
CN117305726A CN202311052177.1A CN202311052177A CN117305726A CN 117305726 A CN117305726 A CN 117305726A CN 202311052177 A CN202311052177 A CN 202311052177A CN 117305726 A CN117305726 A CN 117305726A
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content
alloy
resistant steel
temperature
steel alloy
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李洪立
李刚
杨庆松
郑晓丹
姜文婷
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BEIJING SHOUGANG GITANE NEW MATERIALS CO LTD
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BEIJING SHOUGANG GITANE NEW MATERIALS CO LTD
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B7/00—Blast furnaces
    • C21B7/18—Bell-and-hopper arrangements
    • C21B7/20—Bell-and-hopper arrangements with appliances for distributing the burden
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • 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
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
    • 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

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

The application relates to the technical field of alloys, in particular to a heat-corrosion-resistant steel alloy and a preparation method and application thereof. The chemical components of the hot corrosion resistant steel alloy comprise: C. cr, W, mo, V, Y, mn, si, al, ni, nb, hf and Fe; wherein, the content of W is 4.6-6.0% by mass, the content of Mo is 2.0-4.0%, the content of V is 0.5-0.7%, the content of Y is 0.10-0.20%, the content of Al is 0.05-0.10%, the content of Nb is 2.0-3.0%, the content of Hf is 0.2-0.5%, the content of C is less than or equal to 0.25%, the content of Cr is 11.5-12.5%, the content of Mn is 0.5-0.8%, the content of Si is 0.3-0.5%, and the content of Ni is less than or equal to 0.20%. The high-temperature corrosion resistance of the alloy for the movable arm of the blast furnace top distribution chute is improved, and the high-temperature strength is improved.

Description

Heat-corrosion-resistant steel alloy and preparation method and application thereof
Technical Field
The application relates to the technical field of alloys, in particular to a heat-corrosion-resistant steel alloy and a preparation method and application thereof.
Background
The blast furnace is an important process in steel production, and is an important process for obtaining steelmaking pig iron. The iron-making raw materials enter the furnace through a blast furnace top charging system, and the current furnace top charging system mainly adopts a bell-less furnace top mode. The blast furnace distribution chute is driven by the furnace top gear box to realize accurate tilting and rotating operation so as to meet the requirements of the iron-making process on spiral, multi-ring, single-ring, fan-shaped and fixed-point distribution and ensure that the blast furnace distribution is executed according to a given distribution system.
However, most of the current alloys for supporting shafts of the movable arms of the distribution chute at the top of the blast furnace in steel mills are required to have higher tensile strength, good plasticity and toughness and excellent technological properties, and are commonly used in industry for manufacturing gears, rear shafts, connecting rods and other parts with extremely high load. However, the distribution chute is subject to flushing and abrasion of the furnace burden and flushing and corrosion of high-temperature gas flow in the furnace, so that the distribution chute is finally failed due to burning deformation and breakage. The existing alloy material can not meet the long-term use requirement, and a novel heat-corrosion-resistant steel alloy with high-temperature fatigue resistance and excellent high-temperature strength is necessary to be developed.
Disclosure of Invention
The application provides a heat-resistant corrosion steel alloy and a preparation method and application thereof, which are used for solving the technical problem that the heat-resistant corrosion performance of the existing alloy for a blast furnace top distribution chute movable arm is poor.
In a first aspect, the present application provides a hot corrosion resistant steel alloy having the chemical composition comprising: C. cr, W, mo, V, Y, mn, si, al, ni, nb, hf and Fe; wherein, the mass fraction of the material is calculated,
the content of W is 4.6-6.0%, the content of Mo is 2.0-4.0%, the content of V is 0.5-0.7%, the content of Y is 0.10-0.20%, the content of Al is 0.05-0.10%, the content of Nb is 2.0-3.0%, and the content of Hf is 0.2-0.5%.
Optionally, in the chemical composition of the hot corrosion resistant steel alloy, the content of W is 4.6-5.0% by mass, the content of Mo is 2.0-3.0% by mass, the content of V is 0.5-0.6% by mass, the content of Y is 0.10-0.15% by mass, the content of Al is 0.05-0.08% by mass, the content of Nb is 2.0-2.5% by mass, and the content of Hf is 0.2-0.4% by mass.
Optionally, in the chemical components of the hot corrosion resistant steel alloy, the content of C is less than or equal to 0.25%, the content of Cr is 11.5-12.5%, the content of Mn is 0.5-0.8%, the content of Si is 0.3-0.5%, and the content of Ni is less than or equal to 0.20% by mass.
In a second aspect, the application provides the application of the heat-corrosion-resistant steel alloy in the preparation of a blast furnace top distribution chute movable arm.
In a third aspect, the present application provides a method for preparing a hot corrosion resistant steel alloy according to any one of the embodiments of the first aspect, the method comprising:
smelting raw materials, controlling chemical components of slag, and casting to obtain an alloy rod;
purifying the alloy rod, and controlling chemical components of refining slag to obtain an alloy ingot;
and heating the alloy ingot, and then rolling and heat treatment after rolling to obtain the heat corrosion resistant steel alloy.
Optionally, the chemical components of the slag include:
CaF 2 、Al 2 O 3 CaO; the CaF is 2 Said Al 2 O 3 The CaO is mixed in a ratio of 20-30:20-30:45-65.
Optionally, the chemical components of the refining slag include:
Al 2 O 3 and CaF 2 The method comprises the steps of carrying out a first treatment on the surface of the The Al is 2 O 3 And the CaF 2 The ratio of (2) is 20-30:70-80.
Optionally, the heated process parameters include: heating temperature and heating time; wherein the heating temperature is 1100-1200 ℃, and the heating time is 90-400min.
Optionally, the initial rolling temperature of the rolling is 1150-1190 ℃.
Optionally, the process parameters of the heat treatment include: heat treatment temperature and heat treatment time; wherein the heat treatment temperature is 950-1050 ℃, and the heat treatment time is 2-4h.
Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:
according to the heat-corrosion-resistant steel alloy provided by the embodiment of the application, chemical components are reasonably designed, and the W is used for carrying out composite strengthening on austenite, so that the alloy maintains high plasticity and excellent oxidation resistance, and meanwhile, the heat resistance is greatly improved; the softening temperature and the recrystallization temperature after deformation strengthening are improved by Mo, the creep resistance of ferrite is greatly improved, cementite aggregation at high temperature can be inhibited, precipitation of special carbide is promoted, and the heat resistance of steel is improved; v can form tiny, uniform and highly dispersed carbide and nitride particles in steel, can prevent the aggregation and growth of the carbide and reduce the tendency of elements such as chromium, molybdenum and the like to be depleted in solid solution, thereby improving the structural stability and creep resistance of the steel; y obviously enhances the high-temperature corrosion resistance, oxidation resistance and strength of the alloy, and is beneficial to improving the working temperature of alloy wires and resistance elements; the addition of Al to the steel can significantly improve the oxidation resistance of the steel, and Al refines the grains of the steel, but it promotes carbide spheroidization and graphitization; the good influence of Nb on the heat resistance of the low alloy heat corrosion resistant steel is mainly due to the fact that niobium and carbon form stable niobium carbide, and the carbide is uniformly distributed in a matrix in the form of fine particles to play a role of precipitation strengthening; the residual niobium in the steel enters the alpha solid solution to obviously increase the lattice atomic bond attraction, improve the recrystallization temperature and increase the lattice distortion, and strengthen the alpha solid solution; after the niobium is combined with carbon, W, mo element is promoted to enter solid solution to play an indirect strengthening role; when Hf is added to the alloy, the HfC has the lowest Gibbs free energy to be generated and satisfies all the conditions required for substitution as compared with NbC, so that Hf can substitute Nb to form a composite MC carbide and creep resistance is improved. By combining C, cr, mn, si, ni, the high-temperature corrosion resistance of the alloy for the movable arm of the blast furnace top distribution chute is improved, and the high-temperature strength is improved.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
FIG. 1 is a schematic flow chart of a method for preparing a hot corrosion resistant steel alloy according to an embodiment of the present application;
FIG. 2 is a graph of the high temperature corrosion effect of a 35CrMo alloy provided by the present application;
FIG. 3 is a graph showing the high temperature corrosion effect of a hot corrosion resistant steel alloy provided in example 1 of the present application;
fig. 4 is a graph comparing the thermal expansion coefficients of a 35CrMo alloy and an alloy of example 1 provided in the examples of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.
Various embodiments of the present application may exist in a range format; it should be understood that the description in a range format is merely for convenience and brevity and should not be interpreted as a rigid limitation on the scope of the application. It is therefore to be understood that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that a description of a range from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, wherever applicable. In addition, whenever a numerical range is referred to herein, it is meant to include any reference number (fractional or integer) within the indicated range.
In this application, unless otherwise indicated, terms of orientation such as "upper" and "lower" are used specifically to refer to the orientation of the drawing in the figures. In addition, in the description of the present application, the terms "include", "comprise", "comprising" and the like mean "including but not limited to". Relational terms such as "first" and "second", and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Herein, "and/or" describing an association relationship of an association object means that there may be three relationships, for example, a and/or B, may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. Herein, "at least one" means one or more, and "a plurality" means two or more. "at least one", "at least one" or the like refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.
Unless specifically indicated otherwise, the various raw materials, reagents, instruments, equipment, and the like used in this application are commercially available or may be prepared by existing methods.
The application is based on the fact that most blast furnace top distribution chute movable arm support shafts are made of 35CrMo. The 35CrMo alloy steel has higher tensile strength, good plasticity and toughness and excellent technological performance, and is commonly used for manufacturing parts such as gears, rear axles, connecting rods and the like with extremely high load in industry. The 35CrMo alloy structural steel has high static strength, impact toughness and high fatigue limit, the hardenability is higher than that of 40Cr, the high creep strength and the high lasting strength are realized at high temperature, and the long-term working temperature is 500 ℃. The 35CrMo alloy material adopted by the movable arm of the blast furnace top distribution chute can not meet the long-term use requirement, and has poor heat resistance and corrosion resistance. Referring to the problems in the using process of the 35CrMo material, the low-alloy heat-resistant corrosion steel scheme for the blast furnace movable arm is formed by taking low-alloy heat-resistant corrosion steel 2Cr12 as a basic material, wherein the 2Cr12 comprises the following components: the content of C is less than or equal to 0.25%, the content of Cr is 11.5-12.5%, the content of Mn is 0.5-0.8%, the content of Si is 0.3-0.5%, and the content of Ni is less than or equal to 0.20%.
In a first aspect, the present application provides a hot corrosion resistant steel alloy having the chemical composition comprising: C. cr, W, mo, V, Y, mn, si, al, ni, nb, hf and Fe; wherein, the mass fraction of the material is calculated,
the content of W is 4.6-6.0%, the content of Mo is 2.0-4.0%, the content of V is 0.5-0.7%, the content of Y is 0.10-0.20%, the content of Al is 0.05-0.10%, the content of Nb is 2.0-3.0%, and the content of Hf is 0.2-0.5%.
In some embodiments, in the chemical composition of the hot corrosion resistant steel alloy, the content of W is 4.6 to 5.0%, the content of Mo is 2.0 to 3.0%, the content of V is 0.5 to 0.6%, the content of Y is 0.10 to 0.15%, the content of Al is 0.05 to 0.08%, the content of Nb is 2.0 to 2.5%, and the content of Hf is 0.2 to 0.4% by mass.
The positive effect of controlling the content of W to be 4.6-6.0 percent: w is added in higher amounts in wrought superalloys, for example, GH1015 is added in the range of 4.8% -5.8%, GH1016 is added in the range of 5.0% -6.0%, GH1131 is added in the range of 4.8% -6.0%, but Ni content in superalloys is higher. The GH1015 alloy is a high-performance iron-nickel-based superalloy developed in China, and austenite is compositely reinforced by W, al and Nb elements which are rich in about 10% of the total amount in China, so that the alloy has high plasticity and excellent oxidation resistance, and meanwhile, the heat resistance is greatly improved, and meanwhile, the alloy has good technological properties such as stamping, welding, hot working and the like. The comprehensive performance level of the alloy is equivalent to that of nickel-based alloy Hastelloy X widely used in Sumei. The heat strength is slightly higher than that of the alloy, and the alloy is suitable for manufacturing parts of the combustion chamber of the aeroengine working below 900-950 ℃. If the W content is too high, coarsening of the high-temperature precipitated phase during heat treatment is accelerated to a certain extent; if the W content is too low, the endurance strength and creep property of the hot corrosion resistant steel are adversely affected to some extent. Specifically, the content of W may be 4.6%, 5.0%, 5.5%, 6.0%, or the like.
The positive effect of controlling the Mo content to be 2.0-4.0 percent: the improvement in the endurance strength is caused by solid solution strengthening of Mo and precipitation strengthening of Mo, V, nb. The main precipitates in the steel include M23C precipitated along grain boundaries and martensite lath boundaries, and Fe2Mo and M6C precipitated in ferrite, grain boundaries and martensite. Fe2Mo and M6C have important contribution to maintaining high-temperature long-time lasting strength. The aggregation and growth of these precipitates will lead to a decrease in the endurance strength. The level of the permanent strength is therefore dependent on the type, size, distribution and rate of aggregation of the precipitates in the steel. The Mo element has solid solution strengthening effect on ferrite, and meanwhile, the stability of carbide is improved, so that the strength of steel is improved. The Mo increases the softening temperature and recrystallization temperature after deformation strengthening, greatly increases the creep resistance of ferrite, can inhibit cementite from gathering at 450-600 ℃ and promotes precipitation of special carbide, thereby becoming the most effective alloy element for improving the heat resistance of steel. If the Mo content is too high, precipitation of intermetallic phases in the steel, such as sigma, kappa, and Laves phases, is promoted to some extent, which adversely affects both corrosion resistance and mechanical properties of the steel, in particular, results in a decrease in plasticity and toughness; if the Mo content is too low, the heat resistance of the hot corrosion resistant steel is not improved to some extent. Specifically, the Mo content may be 2.0%, 3.0%, 4.0%, or the like.
The positive effect of controlling the content of V to be 0.5-0.7 percent: the carbide and nitride particles which are tiny, uniform and highly dispersed can be formed in the steel, the aggregation and growth of the carbide can be prevented, and the tendency of depletion of elements such as chromium, molybdenum and the like in solid solution can be reduced, so that the structural stability and creep resistance of the steel are improved. If the V content is too high, the refining of the structure and the crystal grains in the steel is not facilitated to a certain extent, and the hardness, the strength, the ductility and the wear resistance of the steel are reduced; if the V content is too low, it may result in a steel having low hardness, poor strength, poor ductility and wear resistance to some extent. Specifically, the content of V may be 0.5%, 0.6%, 0.7%, or the like.
The positive effect of controlling the content of Y to be 0.10-0.20 percent: the high-temperature corrosion resistance, oxidation resistance and strength of the alloy are obviously enhanced, and the working temperature of the alloy wire and the resistance element is improved. If the content of Y is too high, the atoms can form inter-crystal distortion to a certain extent and increase dislocation resistance, so that solid solution strengthening occurs and the mechanical property of the alloy is reduced; if the content of Y is too low, the alloy is unfavorable to high temperature corrosion resistance, oxidation resistance and strength to some extent, and the working temperature of the alloy wire and the resistance element is reduced. Specifically, the content of Y may be 0.10%, 0.15%, 0.20%, or the like.
The positive effect of controlling the content of Al to be 0.05-0.10 percent: the addition of Al to steel can significantly improve the oxidation resistance of the steel, al refines the grains of the steel, but it promotes carbide spheroidization and graphitization. If the content of the Al is too high, carbide spheroidization and graphitization can be promoted to a certain extent, and the oxidation resistance of the steel is reduced; if the content of Al is too low, grain refinement of the steel is to some extent disadvantageous. Specifically, the content of Al may be 0.05%, 0.07%, 0.10%, or the like.
The positive effect of controlling the Nb content to be 2.0-3.0 percent: the good influence of niobium on the heat resistance of the low alloy heat corrosion resistant steel is mainly due to the fact that niobium and carbon form stable niobium carbide, and the carbide is uniformly distributed in a matrix in the form of fine particles to play a role of precipitation strengthening; the residual niobium in the steel enters the alpha solid solution to obviously increase the lattice atomic bond attraction, improve the recrystallization temperature and increase the lattice distortion, and strengthen the alpha solid solution; niobium and carbon combine to promote W, mo element to enter solid solution for indirect strengthening. If the Nb content is too high, the excessive Nb element in the alloy is segregated to a certain extent, so that larger tissue difference occurs in the interior of the crystal grains, and the mechanical property and the wear resistance of the alloy are affected; if the content of Nb is too low, niobium and carbon cannot form stable niobium carbide to some extent, and the carbide is uniformly distributed in the matrix as fine particles, and cannot play a role in precipitation strengthening. Specifically, the Nb content may be 2.0%, 2.5%, 3.0%, etc.
The positive effect of controlling the content of Hf to be 0.2-0.5 percent: the relative stability of carbides in an alloy depends on the affinity of the alloying element for C, i.e. the strength of the tendency of the alloying element to form covalent bonds with C. If multiple carbide-forming elements are present in the alloy at the same time, typically the strong tungsten carbide-forming element preferentially combines with C to form its carbide. Since the amount of Nb added to the alloy is large, primary carbide NbC mainly composed of Nb is preferentially formed in the liquid state of the alloy. When Hf is added to the alloy, the HfC has the lowest Gibbs free energy to be formed as compared with NbC, and satisfies all the conditions required for substitution, so that Hf can substitute Nb to form a composite MC-type carbide. As a result of experiments, it was found that the amount of Nb substitution in the MC carbide increases with the increase of the added amount of Hf, thereby forming an MC carbide mainly composed of NbC and containing Hf, and improving the high-temperature strength. If the content of Hf is too high, a large amount of MC-type carbide will precipitate at the grain boundary to some extent, which is unfavorable for the creep performance of the alloy; if the content of Hf is too low, the Hf may be unable to displace Nb to form a composite MC carbide to some extent. Specifically, the content of Hf may be 0.2%, 0.4%, 0.5%, etc.
Preferably, the W content may be 4.6 to 5.0%, the Mo content may be 2.0 to 3.0%, the V content may be 0.5 to 0.6%, the Y content may be 0.10 to 0.15%, the Al content may be 0.05 to 0.08%, the Nb content may be 2.0 to 2.5%, and the Hf content may be 0.2 to 0.4%.
In some embodiments, in the chemical composition of the hot corrosion resistant steel alloy, the content of C is equal to or less than 0.25% by mass, the content of Cr is 11.5-12.5%, the content of Mn is 0.5-0.8%, the content of Si is 0.3-0.5%, and the content of Ni is equal to or less than 0.20%.
The positive effect of controlling the content of C to be less than or equal to 0.25 percent is that: the carbide is not biased to gather, keeps a dispersion state, and is favorable for inhibiting the diffusion of alloy elements to the carbide. Specifically, the content of C may be 0.25%, 0.24%, 0.23%, or the like.
The positive effect of controlling the Cr content to be 11.5-12.5 percent: cr is added into the heat-resistant corrosion-resistant steel to improve the oxidation resistance and corrosion resistance of the steel, and in addition, the Cr can improve the durability and creep limit of the steel within a certain content range. Specifically, the Cr content may be 11.5%, 12.0%, 11.5%, etc.
The positive effect of controlling the Mn content to be 0.5-0.8 percent: the strength and hardness of the steel are improved, and the hot workability of the steel is improved. Specifically, the Mn content may be 0.5%, 0.6%, 0.7%, 0.8%, or the like.
The positive effect of controlling the Si content to be 0.3-0.5 percent: the elastic limit, yield point and tensile strength of the steel are improved. Specifically, the content of Si may be 0.3%, 0.4%, 0.5%, or the like.
The positive effect of controlling the Ni content to be less than or equal to 0.20 percent is that: improves the corrosion resistance of steel to acid and alkali, and has the rust resistance and heat resistance at high temperature. Specifically, the Ni content may be 0.20%, 0.18%, 0.19%, or the like.
In a second aspect, the application provides the application of the heat-corrosion-resistant steel alloy in the preparation of a blast furnace top distribution chute movable arm.
The movable arm material of the blast furnace top distribution chute can meet the following service conditions:
the temperature changes dynamically, and the temperature fluctuation complicates the service environment. The safe service temperature interval is below 600 ℃, and the time length is 46.88 percent; 600-800 ℃ of the secondary safety service temperature interval and 35.68 percent of the secondary safety service temperature interval; wherein the temperature of 600-700 ℃ accounts for 21.02 percent; the dangerous service temperature interval is more than 800 ℃, and the proportion is 17.44%. Therefore, the high temperature mechanical properties of the boom material must meet design criteria. The heat-corrosion-resistant steel alloy is used for preparing the movable arm of the distribution chute at the top of the blast furnace, so that the service life of the movable arm is prolonged at high temperature.
In a third aspect, referring to fig. 1, the present application provides a method for preparing a hot corrosion resistant steel alloy according to any one of the embodiments of the first aspect, and the method includes, based on the chemical components, improving the preparation process parameters, and improving the hot corrosion resistance of the steel, where:
s1, smelting raw materials, controlling chemical components of slag, and casting to obtain an alloy rod;
in some embodiments, the slag comprises the chemical composition of:
CaF 2 、Al 2 O 3 CaO; the CaF is 2 Said Al 2 O 3 The CaO is mixed in a ratio of 20-30:20-30:45-65.
In the examples of the present application, caF is present in the slag 2 The function of (3): the fluidity of molten steel can be improved, and harmful impurities of sulfur and phosphorus are removed; al (Al) 2 O 3 The function of (3): improving the stability of the steel slag and stabilizing the alkalinity of the steel slag; action of CaO: is favorable for dephosphorization reaction. The dephosphorization reaction is carried out on the slag-steel interface, and the addition of lime increases the alkalinity, i.e. increases the content of calcium oxide in the slag, which is beneficial to the dephosphorization reaction. Controlling CaF 2 、Al 2 O 3 The CaO has the positive effects that the ratio of 20-30:20-30:45-65: the steel slag is in the optimal melting proportion, the alkalinity range is proper, and the fluidity of the steel slag is good. If the proportion of the slag does not fall within the above numerical range, it adversely affects: the steel slag has high viscosity and poor fluidity. Specifically, the CaF 2 、Al 2 O 3 The CaO may be mixed in the following proportions20:20: 45. 30:30: 65. 25:25:55, etc. In addition, the slag consumption is 50-60Kg/t, and aluminum powder is used for deoxidization in the smelting process. The tapping temperature is 1620-1650 ℃. Rare earth is inserted into a ladle, and the ladle is stirred for 2 to 3 minutes by bottom argon blowing, so that the uniformity of components is ensured, and the alloy rod is cast.
S2, purifying the alloy rod, and controlling chemical components of refining slag to obtain an alloy ingot;
in some embodiments, the chemical composition of the refining slag comprises:
Al 2 O 3 and CaF 2 The method comprises the steps of carrying out a first treatment on the surface of the The Al is 2 O 3 And the CaF 2 The ratio of (2) is 20-30:70-80.
In the embodiment of the application, the alloy rod is used as a consumable electrode, and a single-phase electroslag remelting furnace is used for purification to obtain an alloy ingot. In the refining slag, caF 2 The function of (3): can improve the fluidity of molten steel and remove harmful impurities such as sulfur and phosphorus; al (Al) 2 O 3 The function of (3): improving the stability of the steel slag and stabilizing the alkalinity of the steel slag. Control of Al 2 O 3 And CaF 2 The ratio of (2) is 20-30: 70-80: the steel slag is in the optimal melting proportion, the alkalinity range is proper, and the fluidity of the steel slag is good. If the proportion of the refining slag does not satisfy the above numerical range, it adversely affects: the steel slag has high viscosity and poor fluidity. Specifically, the Al 2 O 3 And CaF 2 The ratio of (2) can be 20: 70. 25: 75. 30:80, etc.
And S3, heating the alloy ingot, and then rolling and heat treatment after rolling to obtain the heat-corrosion-resistant steel alloy.
In some embodiments, the heated process parameters include: heating temperature and heating time; wherein the heating temperature is 1100-1200 ℃, and the heating time is 90-400min.
The positive effect of controlling the heating temperature to 1100-1200℃ is that: the billet is heated to a uniform temperature suitable for rolling, the plasticity of the steel is improved, the deformation resistance is reduced, and the steel is easy to deform. If the temperature is too high, the temperature of a hearth is too high to a certain extent, and the metal in the furnace is overheated and excessively burnt; if the temperature is too low, the plasticity of the steel is not improved to a certain extent, the deformation resistance cannot be reduced, and the steel is not easy to deform. Specifically, the heating temperature may be 1100 ℃, 1150 ℃, 1200 ℃, or the like.
The positive effect of controlling the heating time to be 90-400min is that: the gradual reduction of the temperature difference of the section is promoted, the heat obtained on the surface of the steel billet is diffused to the inside in a heat conduction mode, the steel billet is fully heated, and the plasticity of the steel is improved. Specifically, the heating time may be 90min, 150min, 200min, 250min, 300min, 350min, 400min, etc.
In some embodiments, the initial rolling temperature of the rolling is 1150-1190 ℃.
The method has the positive effects that the initial rolling temperature of rolling is controlled to 1150-1190 ℃: the burning loss can be reduced, the overburning and overheating of the steel billet are prevented, the steel ingot tissue is uniform, and the rolling is facilitated. If the temperature is too high, the grains of the steel can grow excessively to a certain extent, the connection among the grains is weakened, and the steel becomes brittle; if the temperature is too low, the rolling mill load increases to some extent, which increases the power consumption and causes disadvantages to the rolls, guides, etc. Specifically, the initial rolling temperature of the rolling may be 1150 ℃, 1170 ℃, 1190 ℃, or the like. After rolling, a round bar alloy with a diameter of 30mm was produced.
In some embodiments, the process parameters of the heat treatment include: heat treatment temperature and heat treatment time; wherein the heat treatment temperature is 950-1050 ℃, the heat treatment time is 2-4h, and the finished product is obtained by water cooling after heat treatment.
The positive effect of controlling the heat treatment temperature to 950-1050℃: the recrystallization of the heat-resistant corrosion-resistant steel alloy structure is promoted, the residual stress in the hot rolling process is eliminated, the plasticity is improved, and the uniformity and consistency of crystal grains are promoted. If the temperature is too high, overheat and overburning of the heat-resistant corrosion-resistant steel alloy can be caused to a certain extent; if the temperature is too low, recrystallization of the hot corrosion resistant steel alloy structure is not favored to some extent, and a uniform structure cannot be formed. Specifically, the heat treatment temperature may be 950 ℃, 970 ℃, 990 ℃, 1010 ℃, 1030 ℃, 1050 ℃, or the like.
The positive effect of controlling the heat treatment time to be 2-4h is that: the recrystallization of the heat-resistant corrosion-resistant steel alloy structure is promoted, the residual stress in the hot rolling process is eliminated, the plasticity is improved, and the uniformity and consistency of crystal grains are promoted. Specifically, the heat treatment time may be 2 hours, 3 hours, 4 hours, or the like.
The preparation method of the heat-corrosion-resistant steel alloy aims at the advantages of the prior art: and the high-temperature and corrosion resistance of the heat-corrosion-resistant steel alloy is improved.
The preparation method of the heat-resistant corrosion steel alloy is realized based on the chemical components of the heat-resistant corrosion steel alloy, and the chemical components of the heat-resistant corrosion steel alloy can refer to the embodiment, and because the preparation method of the heat-resistant corrosion steel alloy adopts part or all of the technical schemes of the embodiment, the preparation method at least has all the beneficial effects brought by the technical schemes of the embodiment, and the description is omitted herein.
The present application is further illustrated below in conjunction with specific examples. It should be understood that these examples are illustrative only of the present application and are not intended to limit the scope of the present application. The experimental procedures, which are not specified in the following examples, are generally determined according to national standards. If the corresponding national standard does not exist, the method is carried out according to the general international standard, the conventional condition or the condition recommended by the manufacturer.
The present embodiments provide a hot corrosion resistant steel alloy, in particular, the chemical composition of which is shown in table 1.
TABLE 1 chemical composition (wt%) of hot corrosion resistant steel alloy, balance Fe and unavoidable impurities
Based on the chemical components, and in combination with improvement of preparation process parameters, the embodiment of the application provides a preparation method of a heat-corrosion-resistant steel alloy, which comprises the following steps:
s11, smelting raw materials, controlling chemical components of slag, and casting to obtain an alloy rod;
s21, purifying the alloy rod, and controlling chemical components of refining slag to obtain an alloy ingot;
and S31, heating the alloy ingot, and then rolling and heat treatment after rolling to obtain the heat-corrosion-resistant steel alloy. See table 2 for specific process parameters.
Table 2 preparation process parameters of hot corrosion resistant steel alloys
The results of the high temperature thermal fatigue performance test of the hot corrosion resistant steel alloy of the present example and the hot corrosion resistant steel alloy prepared in the comparative example are shown in table 3. The high temperature thermal fatigue test is one of the indicators for checking the durability of materials. The sample is checked by using a gas thermal shock automatic check platform, the surface of the sample is heated by using oxypropane high-temperature gas in the heating process, and the surface of the sample is cooled by using compressed air in the cooling process. The highest temperature is 1000 ℃, and the lowest temperature is 400 ℃. The total heat shock cycle is 100 times, the heat cycle is heated to 1000 ℃ from 400 ℃ for 1min, then cooled to 400 ℃, the single cycle time without heat preservation time is about 2min, and the surface of the sample is photographed and recorded in the process. Specifically, please refer to example 1 (fig. 3) and 35CrMo alloy (fig. 2), example 1 is more excellent in high temperature corrosion resistance and longer in service life.
TABLE 3 results of high temperature thermal fatigue Performance test of hot corrosion resistant Steel alloys
Through the designed heat-resistant corrosion steel alloy of the embodiment of the application, the high-temperature thermal fatigue performance of the heat-resistant corrosion steel alloy is improved, so that the service life of the movable arm material of the distribution chute at the top of the blast furnace is prolonged, and the embodiments of the comparative examples 1-2 are obviously not in the embodiments of the application, so that the high-temperature thermal fatigue performance is poorer than that of the embodiment of the application.
In addition, the hot corrosion resistant steel alloy prepared in example 1 above was subjected to a high temperature strength test using a UTM5105 type electronic universal tester. See table 4 for the results.
TABLE 4 results of high temperature strength test experiments
From table 4, it can be seen that the hot corrosion resistant steel alloy (2 Cr12 WMo) prepared in example 1 of the present application has excellent high temperature strength, and improved heat resistance.
Furthermore, sample size using a North mineral Germany relaxation resistant Netzsch thermal expansion instrument NETZSCH DIL 402SUThe temperature is 20-1000 deg.c and the temperature raising speed is 5.0K/min. Referring to fig. 4, it can be seen that the thermal expansion performance of the 2Cr12WMo alloy of the present embodiment is significantly better than that of the 35CrMo alloy.
The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A hot corrosion resistant steel alloy, characterized in that the chemical composition of the hot corrosion resistant steel alloy comprises:
C. cr, W, mo, V, Y, mn, si, al, ni, nb, hf and Fe; wherein, the mass fraction of the material is calculated,
the content of W is 4.6-6.0%, the content of Mo is 2.0-4.0%, the content of V is 0.5-0.7%, the content of Y is 0.10-0.20%, the content of Al is 0.05-0.10%, the content of Nb is 2.0-3.0%, and the content of Hf is 0.2-0.5%.
2. The hot corrosion resistant steel alloy according to claim 1, wherein in the chemical composition of the hot corrosion resistant steel alloy, the content of W is 4.6 to 5.0%, the content of Mo is 2.0 to 3.0%, the content of V is 0.5 to 0.6%, the content of Y is 0.10 to 0.15%, the content of Al is 0.05 to 0.08%, the content of Nb is 2.0 to 2.5%, and the content of Hf is 0.2 to 0.4% by mass.
3. The hot-corrosion-resistant steel alloy according to claim 1 or 2, wherein, in the chemical composition of the hot-corrosion-resistant steel alloy, in mass fraction,
the content of C is less than or equal to 0.25%, the content of Cr is 11.5-12.5%, the content of Mn is 0.5-0.8%, the content of Si is 0.3-0.5%, and the content of Ni is less than or equal to 0.20%.
4. Use of a hot corrosion resistant steel alloy according to any one of claims 1 to 3 for the manufacture of a blast furnace roof distribution chute boom.
5. A method for preparing a hot corrosion resistant steel alloy according to any one of claims 1 to 3, comprising:
smelting raw materials, controlling chemical components of slag, and casting to obtain an alloy rod;
purifying the alloy rod, and controlling chemical components of refining slag to obtain an alloy ingot;
and heating the alloy ingot, and then rolling and heat treatment after rolling to obtain the heat corrosion resistant steel alloy.
6. The method according to claim 5, wherein the chemical composition of the slag comprises:
CaF 2 、Al 2 O 3 CaO;
the CaF is 2 Said Al 2 O 3 The CaO is mixed in a ratio of 20-30:20-30:45-65.
7. The method of claim 5, wherein the chemical composition of the refining slag comprises:
Al 2 O 3 and CaF 2 ；
The Al is 2 O 3 And the CaF 2 The ratio of (2) is 20-30:70-80.
8. The method of claim 5, wherein the heated process parameters comprise:
heating temperature and heating time; wherein,
the heating temperature is 1100-1200 ℃, and the heating time is 90-400min.
9. The method according to claim 5, wherein the initial rolling temperature of the rolling is 1150-1190 ℃.
10. The method of claim 5, wherein the process parameters of the heat treatment comprise:
heat treatment temperature and heat treatment time; wherein,
the heat treatment temperature is 950-1050 ℃, and the heat treatment time is 2-4h.
CN202311052177.1A 2023-08-21 2023-08-21 Heat-corrosion-resistant steel alloy and preparation method and application thereof Pending CN117305726A (en)

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JPH0885850A (en) * 1994-09-20 1996-04-02 Sumitomo Metal Ind Ltd High chromium ferritic heat resistant steel
JPH08319545A (en) * 1995-05-24 1996-12-03 Mitsubishi Materials Corp Ferritic heat resistant cast steel excellent in high temperature characteristic
JPH09122971A (en) * 1995-10-26 1997-05-13 Sumitomo Metal Ind Ltd Welding material for high-strength, high-corrosion resistant steel having excellent welding procedure characteristic
CN102877002A (en) * 2012-10-24 2013-01-16 章磊 Heat resistant steel for boiler parts and manufacture method of heat resistant steel
CN104651743A (en) * 2013-11-22 2015-05-27 南红艳 Multielement composite heat-resistant steel

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0298127A1 (en) * 1987-01-09 1989-01-11 Hitachi, Ltd. Heat-resistant steel and gas turbine made of the same
KR950014312B1 (en) * 1987-01-09 1995-11-24 가부시끼가이샤 히다찌 세이사구쇼 Gas turbin & spare parts
JPH0885850A (en) * 1994-09-20 1996-04-02 Sumitomo Metal Ind Ltd High chromium ferritic heat resistant steel
JPH08319545A (en) * 1995-05-24 1996-12-03 Mitsubishi Materials Corp Ferritic heat resistant cast steel excellent in high temperature characteristic
JPH09122971A (en) * 1995-10-26 1997-05-13 Sumitomo Metal Ind Ltd Welding material for high-strength, high-corrosion resistant steel having excellent welding procedure characteristic
CN102877002A (en) * 2012-10-24 2013-01-16 章磊 Heat resistant steel for boiler parts and manufacture method of heat resistant steel
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