CN114606370A - Method for reducing shear delamination defect of nitrogen-containing martensitic stainless steel hot-rolled steel plate - Google Patents

Method for reducing shear delamination defect of nitrogen-containing martensitic stainless steel hot-rolled steel plate Download PDF

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CN114606370A
CN114606370A CN202210153959.3A CN202210153959A CN114606370A CN 114606370 A CN114606370 A CN 114606370A CN 202210153959 A CN202210153959 A CN 202210153959A CN 114606370 A CN114606370 A CN 114606370A
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equal
hot
continuous casting
martensitic stainless
stainless steel
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李筱
王志斌
张剑桥
卫争艳
罗刚
李俊
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Shanxi Taigang Stainless Steel Co Ltd
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Shanxi Taigang Stainless Steel Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26—Methods of annealing
    • C21D1/32—Soft annealing, e.g. spheroidising
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
    • 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
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • 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
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0273—Final recrystallisation annealing
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • 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
    • C21D2211/004—Dispersions; Precipitations
    • 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

Abstract

The invention relates to the field of martensitic stainless steel production and manufacturing, in particular to hot rolling of martensitic stainless steel containing nitrogenA method for steel plate shearing delamination defect. A method for reducing the shear delamination defect of a nitrogen-containing martensitic stainless steel hot-rolled steel plate comprises the following steps: the method comprises the following steps: smelting molten steel by adopting a conventional industrial production method; step two: continuously casting the molten steel into a continuous casting plate blank by adopting a continuous casting process; step three: putting the continuous casting plate blank into a stepping heating furnace for heating; step four: taking out the continuous casting slab and continuously rolling the continuous casting slab into a hot rolled steel coil on a hot continuous rolling unitδLess than or equal to 9.5; step five: and (4) loading the hot-rolled steel coil into a bell-type annealing furnace for annealing. The invention greatly improves the production efficiency and the operation profit of steel mills and downstream enterprises thereof.

Description

Method for reducing shear delamination defect of nitrogen-containing martensitic stainless steel hot-rolled steel plate
Technical Field
The invention relates to the field of martensitic stainless steel production and manufacturing, in particular to a method for reducing the shear delamination defect of a hot-rolled steel plate of nitrogenous martensitic stainless steel.
Background
Martensitic stainless steels are a class of stainless steels whose properties can be adjusted by heat treatment (quenching, tempering). In a quenching state, the martensitic stainless steel has a body centered tetragonal (bcc) crystal structure (martensite), has high hardness, strength and wear resistance, simultaneously has ferromagnetism and corrosion resistance of a medium degree and good heat resistance at a temperature lower than 650 ℃, and is widely applied to the fields of civil use, industry, aviation, aerospace and the like, such as cutters, pulleys, medical instruments, valves, bearings and the like.
The nitrogen exists in the form of interstitial atoms in the martensitic stainless steel, and can form nitrides with other elements to be distributed in grain boundaries and matrixes. Nitrogen expands and stabilizes austenite, reduces the high temperature ferrite content, and reduces the number and size of eutectoid carbides in the steel. Therefore, compared with the traditional nitrogen-free martensitic stainless steel, the nitrogen-containing martensitic stainless steel has more excellent toughness, corrosion resistance, high temperature resistance and welding performance, and is widely applied to the fields of steam turbine generator rotor materials, self-tapping screws, engine rolling bearings, tools, high-end tableware and the like.
The nitrogen-containing martensitic stainless steel is generally delivered in a hot-rolled annealed state in which its structure consists of a ferritic matrix and spheroidal carbides uniformly distributed thereon. However, in practical production practice, particularly for thick hot rolled steel plates, due to unreasonable component design, improper setting of process parameters such as smelting and hot rolling, and the like, defect structures such as center segregation, high-temperature ferrite, chain carbides and mixed crystals are easily formed in the thickness direction of the steel plates. The existence of these structures easily causes the downstream users to have shear delamination defects when shearing and striping the steel plates. The defects reduce the production efficiency of downstream enterprises, improve the defective rate and the production cost on one hand, and increase the quality dissimilarity of iron and steel companies on the other hand, so that the iron and steel companies bear huge economic losses. Therefore, it is important to develop a process method for alleviating or even eliminating the shear delamination defect of the hot rolled steel sheet of the martensitic stainless steel containing nitrogen.
Disclosure of Invention
The invention aims to solve the problems and provides a method for reducing the shear delamination defect of a hot rolled steel plate of a martensitic stainless steel containing nitrogen.
The purpose of the invention is realized as follows: a method for reducing the shear delamination defect of a nitrogen-containing martensitic stainless steel hot-rolled steel plate comprises the following steps: the method comprises the following steps: smelting molten steel by adopting a conventional industrial production method; step two: continuously casting the molten steel into a continuous casting slab by adopting a continuous casting process, wherein the continuous casting process comprises the steps of 10-30 ℃ of superheat degree of a tundish, 500-700A of electromagnetic stirring current in a secondary cooling area of continuous casting, 2-4 Hz of frequency and 10-20 s of reversing time; step three: putting the continuous casting plate blank into a stepping heating furnace for heating, raising the heating temperature to 1210-; step four: taking out the continuous casting slab and continuously rolling the continuous casting slab into a hot rolled steel coil on a hot continuous rolling unit, wherein the starting rolling temperature in the hot rolling process is 1070-1140 ℃, the finishing rolling temperature is 930-990 ℃, and the ferrite equivalent factor E of the hot rolled steel coilδLess than or equal to 9.5; step five: and (3) putting the hot-rolled steel coil into a bell-type annealing furnace for annealing, wherein the annealing temperature is 810-830 ℃ during annealing, the heat preservation time is 22-30 h, and then, rapidly cooling.
Further, the conventional industrial production method in the step one is a smelting method of basic oxygen converter, argon oxygen furnace decarburization and ladle refining.
Further, the nitrogen-containing martensitic stainless steel comprises the following chemical components in percentage by mass: c is more than or equal to 0.12 and less than or equal to 0.20 percent, Si is more than or equal to 0 and less than or equal to 1.0 percent, Mn is more than or equal to 0 and less than or equal to 1.0 percent, P is more than 0 and less than or equal to 0.045 percent, S is more than or equal to 0.045 percent, N is more than or equal to 0.060 and less than or equal to 0.150 percent, Cr is more than or equal to 13.00 and less than or equal to 14.50 percent, Ni is more than 0 and less than or equal to 0.60 percent, V is more than or equal to 0.20 percent, and the balance is Fe and inevitable impurities.
Further, in the fourth step, the hot rolled steel coil contains the ferrite equivalent factor E of the nitrogen martensitic stainless steelδNot more than 9.5, wherein the ferrite equivalent factor Eδ=Ecr+ETChromium equivalent Ecr= Cr +4Mo +6Si +11V-40C-30N-2Mn-4Ni, temperature equivalent ETAnd (T-1210)/80, wherein T is the heating temperature of the continuous casting slab.
The invention has the beneficial effects that: compared with the existing production method of the nitrogenous martensite stainless steel hot-rolled steel plate, the method can obviously reduce the content of high-temperature ferrite in a spheroidizing annealing structure, reduce center segregation and obtain a uniformly distributed granular carbide structure, thereby obviously reducing the shearing and layering defects of the nitrogenous martensite stainless steel hot-rolled steel plate and greatly improving the production efficiency and the operation profit of steelworks and downstream enterprises thereof.
Detailed Description
In order to reduce the shearing delamination defect of the nitrogen-containing martensitic stainless steel hot-rolled steel plate, improve the structural uniformity of the hot-rolled steel plate and improve the shearing processability of the hot-rolled steel plate, the invention provides a method for reducing the shearing delamination defect of the nitrogen-containing martensitic stainless steel hot-rolled steel plate. The method is mainly realized by controlling ferrite equivalent factor (E)δ) 9.5 or less, wherein E is a nitrogen-containing martensite stainless steel, and the shear delamination defect of a hot-rolled steel sheet is reduced by reducing the high-temperature ferrite content in the nitrogen-containing martensite stainless steelδ = Ecr + ETChromium equivalent Ecr= Cr +4Mo +6Si +11V-40C-30N-2Mn-4Ni, temperature equivalent ET= (T-1210)/80, wherein T (DEG C) represents a heating temperature of a cast slab during hot rolling; in addition, in the continuous casting process, the superheat degree of a tundish is controlled to be 10-30 ℃, electromagnetic stirring is adopted in a continuous casting secondary cooling area, the stirring current is 600A, the frequency is 3.0 Hz, and the reversing time is 15 s; in addition, when the hot-rolled steel coil is annealed in the bell-type annealing furnace, the annealing temperature is 810-830 ℃, and the heat preservation time is 22 h. The nitrogen-containing martensitic stainless steel comprises the following chemical components in percentage by mass: c is more than or equal to 0.12 and less than or equal to 0.20%，0<Si≤1.0%，0<Mn≤1.0%，0<P≤0.045%，0<S≤0.045%，0.060≤N≤0.150%，13.00≤Cr≤14.50%，0<Ni≤0.60%，0<V is less than or equal to 0.20 percent, and the balance is Fe and inevitable impurities. The invention can obviously reduce the shearing delamination defect of the nitrogen-containing martensitic stainless steel hot-rolled steel plate and greatly improve the production efficiency of steel mills and downstream users thereof.
Martensitic stainless steels generally contain a certain amount of high temperature ferrite which is directly precipitated from the molten steel during solidification and remains at room temperature. Once formed, high temperature ferrite is difficult to reduce or eliminate in subsequent manufacturing processes. The structure of the martensitic stainless steel casting blank after solidification consists of martensite, high-temperature ferrite and carbide. The structure of the casting blank after hot rolling comprises banded martensite, banded high-temperature ferrite and carbide. And annealing the hot-rolled martensitic stainless steel by a hood-type annealing furnace to finally obtain a spheroidized annealed structure consisting of an equiaxed ferrite matrix, strip-shaped high-temperature ferrite and grain carbides. The tissue has lower hardness and excellent plasticity, and is suitable for downstream users to carry out deep processing such as shearing, bending and the like on the tissue.
High-temperature ferrite tends to be distributed at grain boundaries, and if more high-temperature ferrite exists in steel, a net distribution structure is easily formed, the plasticity of the material is remarkably deteriorated, and the risk of shear delamination is increased. In addition, carbides in steel are liable to be precipitated at a position having high energy such as a phase boundary, a grain boundary, and the like, and the amount in the grain is relatively small. If the high-temperature ferrite content is large, long-chain carbides tend to be formed at the boundary between the strip-shaped high-temperature ferrite and the ferrite matrix. The long chain carbides destroy the continuity of the material, form weak links of the structure, and when the shearing stress exceeds the shearing strength of the material in the shearing process, cracks are initiated at the weak points formed by the long chain carbides preferentially, propagate along phase boundaries and finally form serious shearing cracks. In addition, if the hot rolling or annealing process is improper, network carbides distributed along the grain boundary are easily formed, equiaxed ferrite matrixes are plastically deformed to be long strips near the cutting edge in the shearing process, the network carbides originally positioned at the grain boundary are also deformed to be chain-shaped, and the newly formed chain-shaped carbides further destroy the continuity of the material, so that the expansion of the shear cracks is accelerated.
Based on the research, in order to reduce the influence of the high-temperature ferrite on the shearing performance of the material, the content of the high-temperature ferrite in the nitrogen-containing martensitic stainless steel needs to be reasonably controlled. The main factors affecting the high-temperature ferrite content include the chemical composition of the material and the heating temperature of the cast slab at the time of hot rolling. Through intensive studies by the inventors, it was found that control of the high-temperature ferrite content can be achieved by controlling the ferrite equivalent factor as follows.
Eδ = Ecr + ET （1）
Wherein EδIs ferrite equivalent factor. EcrIs chromium equivalent, in particular Ecr = Cr + 4Mo + 6Si + 11V - 40C - 30N -2Mn – 4Ni。ETIs a temperature equivalent, in particular ET= T-1210)/80, wherein T (. degree. C.) represents the heating temperature of the cast slab during hot rolling. Practice shows that when E is addedδWhen the value of (2) is controlled to be not more than 9.5, the content of high-temperature ferrite in the nitrogen-containing martensitic stainless steel can be effectively reduced, so that the occurrence of shear crack defects is remarkably reduced.
Further, in order to better solve the problem of shearing and layering of the nitrogenous martensitic stainless steel, in the continuous casting process, the superheat degree of a tundish is controlled to be 10-30 ℃, meanwhile, electromagnetic stirring is adopted in a secondary cooling area of continuous casting, the stirring current is 600A, the frequency is 3.0 Hz, and the reversing time is 15 s. During the solidification process of the continuous casting billet, selective crystallization occurs, low-melting-point elements are deviated to the center, and meanwhile, columnar crystals are developed and easily form the defects of segregation, looseness, shrinkage cavity and the like. These defects form a central segregation band after low-power acid attack. The severe segregation band in the center of the continuous cast slab also causes shear delamination defects.
When the degree of superheat is too high during casting, secondary oxidation of molten steel is accelerated and the refractory lining is eroded, thereby increasing inclusions in the cast slab, and further, defects such as center porosity, columnar crystals, and center segregation are accelerated, so that the degree of superheat needs to be controlled to a low level during casting. In addition, by applying electromagnetic stirring in the secondary cooling zone, the bridges of the dendritic crystals in the liquid core pits can be broken, and the broken dendritic crystals can be used as equiaxed crystal nuclei to enlarge the equiaxed crystal zones, reduce the number of columnar crystals, reduce the central porosity and shrinkage cavity and further inhibit the occurrence of central segregation.
Further, in order to obtain a spheroidized annealed structure with uniformly distributed carbide, when the hot-rolled steel coil is annealed in a cover annealing furnace, the annealing temperature is 810-830 ℃, and the heat preservation time is 22 h. The bell-type annealing furnace is a key process for obtaining a spheroidized annealed structure of the nitrogenous martensitic stainless steel, and the annealing temperature needs to be controlled to be slightly higher than A1Two-phase region of dots. If the temperature is too low and the holding time is too short, martensite in the hot rolled state is hard to transform into ferrite, thereby deteriorating the workability of the material. If the temperature is too high, most carbides are re-dissolved into the matrix, the lattice distortion of the matrix is increased, and the hardness of the material is improved, so that the material is difficult to process.
The method for reducing the shear delamination defect of the hot rolled steel plate of the nitrogen-containing martensitic stainless steel is applicable to the nitrogen-containing martensitic stainless steel and comprises the following chemical components in percentage by mass: c is more than or equal to 0.12 and less than or equal to 0.20 percent, Si is more than or equal to 0 and less than or equal to 1.0 percent, Mn is more than or equal to 0 and less than or equal to 1.0 percent, P is more than 0 and less than or equal to 0.045 percent, S is more than or equal to 0.045 percent, N is more than or equal to 0.060 and less than or equal to 0.150 percent, Cr is more than or equal to 13.00 and less than or equal to 14.50 percent, Ni is more than 0 and less than or equal to 0.60 percent, V is more than or equal to 0.20 percent, and the balance is Fe and inevitable impurities.
The following examples are given to illustrate specific embodiments of the present method, but the present invention is not limited to the following examples.
Example 1:
the nitrogen-containing martensitic stainless steel in the embodiment comprises the following chemical components in percentage by mass:
C 0.17%，Si 0.40%，Mn 0.60%，P 0.022%，S 0.015%，N 0.075%，
Cr 13.67%，Ni 0.08%，V 0.093%。
the balance of Fe and inevitable impurities.
Molten steel is smelted according to the components by adopting the conventional industrial production method of Basic Oxygen Furnace (Basic Oxygen Furnace), argon Oxygen Furnace decarburization (argon decarburization) and Ladle refining (Ladle Furnace) and then continuously cast into a continuous casting slab with the size of 200 mm multiplied by 1240 mm multiplied by 11000 mm. The continuous casting process comprises the following steps: the superheat degree of the tundish is 20 ℃; the electromagnetic stirring current of the continuous casting secondary cooling area is 600A, the frequency is 3.0 Hz, and the reversing time is 15 s. And 4, observing the continuous casting slab at a low power, and not finding a serious center segregation zone.
And (2) putting the continuous casting slab into a stepping heating furnace for heating, raising the heating temperature to 1215 ℃, then preserving the heat for 200 min, taking out the continuous casting slab, and continuously rolling the continuous casting slab on a hot continuous rolling unit to form a hot rolled steel coil with the thickness of 8.0 mm, wherein the initial rolling temperature in the hot rolling process is 1120 ℃, and the final rolling temperature is 955 ℃. The smelting components of the steel plate and the heating temperature of the continuous casting slab in the embodiment are substituted into the formula (1), and the ferrite equivalent factor E of the steel plate can be calculatedδ6.63, below its upper limit of control requirement of 9.5.
And (3) loading the hot-rolled steel coil with the thickness of 8.0 mm into a bell-type annealing furnace for spheroidizing annealing, wherein the annealing heat preservation temperature is 815 ℃, the heat preservation time is 22 hours, and then slowly cooling to 550 ℃ along with the furnace, and then quickly cooling by replacing a cooling cover.
And shearing the annealed steel coil, wherein no shearing delamination defect is found on a shearing cutting edge.
Example 2:
the nitrogen-containing martensitic stainless steel in the embodiment comprises the following chemical components in percentage by mass:
C 0.13%，Si 0.47%，Mn 0.57%，P 0.025%，S 0.002%，N 0.080%，
Cr 13.67%，Ni 0.12%，V 0.07%。
the balance of Fe and inevitable impurities.
Molten steel is smelted according to the components by adopting the conventional industrial production method of Basic Oxygen Furnace (Basic Oxygen Furnace), argon Oxygen Furnace decarburization (argon decarburization) and Ladle refining (Ladle Furnace) and then continuously cast into a continuous casting slab with the size of 200 mm multiplied by 1335 mm multiplied by 10900 mm. The continuous casting process comprises the following steps: the superheat degree of the tundish is 25 ℃; the electromagnetic stirring current of the continuous casting secondary cooling area is 600A, the frequency is 3.0 Hz, and the reversing time is 15 s. And 4, observing the continuous casting slab at a low power, and not finding a serious center segregation zone.
Loading the continuous casting billet into the step-by-step feedingHeating in a heating furnace, keeping the temperature for 200 min after the heating temperature is raised to 1220 ℃, taking out the continuous casting blank and continuously rolling the continuous casting blank on a hot continuous rolling unit to form a hot rolled steel coil with the thickness of 6.0 mm, wherein the initial rolling temperature in the hot rolling process is 1110 ℃, and the final rolling temperature is 966 ℃. The smelting components of the steel plate and the heating temperature of the continuous casting slab in the embodiment are substituted into the formula (1), and the ferrite equivalent factor E of the steel plate can be calculatedδ8.17, below its upper limit of control requirement of 9.5.
And (3) loading the hot-rolled steel coil with the thickness of 6.0 mm into a bell-type annealing furnace for spheroidizing annealing, wherein the annealing heat preservation temperature is 820 ℃, the heat preservation time is 22 hours, slowly cooling to 550 ℃ along with the furnace, and then replacing a cooling cover for rapid cooling.
And shearing the steel coil after the annealing is finished, wherein no shearing layering defect is found on a shearing cutting edge.
The above description is only an embodiment of the present invention, but the structural features of the present invention are not limited thereto, and any changes or modifications within the scope of the present invention by those skilled in the art are covered by the present invention.

Claims (4)

1. A method for reducing the shear delamination defect of a nitrogen-containing martensitic stainless steel hot-rolled steel plate is characterized by comprising the following steps: the method comprises the following steps:
the method comprises the following steps: smelting molten steel by adopting a conventional industrial production method;
step two: continuously casting the molten steel into a continuous casting slab by adopting a continuous casting process, wherein the continuous casting process comprises the steps of 10-30 ℃ of superheat degree of a tundish, 500-700A of electromagnetic stirring current in a secondary cooling area of continuous casting, 2-4 Hz of frequency and 10-20 s of reversing time;
step three: putting the continuous casting plate blank into a stepping heating furnace for heating, raising the heating temperature to 1210-;
step four: taking out the continuous casting slab and continuously rolling the continuous casting slab on a hot continuous rolling unit to form a hot rolled steel coil, wherein the initial rolling temperature in the hot rolling process is 1070-1140 ℃, the final rolling temperature is 930-990 ℃, and the ferrite equivalent factor E of the hot rolled steel coilδ≤9.5；
Step five: and (3) putting the hot-rolled steel coil into a bell-type annealing furnace for annealing, wherein the annealing temperature is 810-830 ℃ during annealing, the heat preservation time is 22-30 h, and then, rapidly cooling.
2. The method for reducing the shear delamination defect of the nitrogen-containing martensitic stainless steel hot rolled steel sheet according to claim 1, wherein the shear delamination defect comprises the following steps: step one, the conventional industrial production method is a smelting method of basic oxygen converter, argon oxygen furnace decarburization and ladle refining.
3. The method for reducing the shear delamination defect of the nitrogen-containing martensitic stainless steel hot rolled steel sheet according to claim 1, wherein the shear delamination defect comprises the following steps: the nitrogen-containing martensitic stainless steel comprises the following chemical components in percentage by mass: c is more than or equal to 0.12 and less than or equal to 0.20 percent, Si is more than or equal to 0 and less than or equal to 1.0 percent, Mn is more than or equal to 0 and less than or equal to 1.0 percent, P is more than 0 and less than or equal to 0.045 percent, S is more than or equal to 0.045 percent, N is more than or equal to 0.060 and less than or equal to 0.150 percent, Cr is more than or equal to 13.00 and less than or equal to 14.50 percent, Ni is more than 0 and less than or equal to 0.60 percent, V is more than or equal to 0.20 percent, and the balance is Fe and inevitable impurities.
4. The method for reducing the shear delamination defect of the nitrogen-containing martensitic stainless steel hot rolled steel sheet according to claim 1, wherein the shear delamination defect comprises the following steps: the ferrite equivalent factor E of the hot-rolled steel coil nitrogenous martensitic stainless steel in the fourth stepδLess than or equal to 9.5, wherein the ferrite equivalent factor Eδ=Ecr+ETChromium equivalent Ecr= Cr +4Mo +6Si +11V-40C-30N-2Mn-4Ni, temperature equivalent ETAnd (T-1210)/80, wherein T is the heating temperature of the continuous casting slab.
CN202210153959.3A 2022-02-20 2022-02-20 Method for reducing shear delamination defect of nitrogen-containing martensitic stainless steel hot-rolled steel plate Pending CN114606370A (en)

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CN101372734A (en) * 2007-08-24 2009-02-25 宝山钢铁股份有限公司 Martensite stainless steel and manufacturing method thereof
CN101693982A (en) * 2009-09-30 2010-04-14 山西太钢不锈钢股份有限公司 Martensite corrosion-resisting steel plate for cutting tool and manufacture method thereof
CN102363864A (en) * 2011-10-10 2012-02-29 刘群联 Method for manufacturing martensite stainless steel tubes
CN102796963A (en) * 2012-08-17 2012-11-28 山西太钢不锈钢股份有限公司 Martensitic stainless steel rectangular billet continuous casting method
CN113118398A (en) * 2021-04-19 2021-07-16 山西太钢不锈钢股份有限公司 Production method for eliminating large-grain carbide of high-carbon martensitic stainless steel continuous casting slab

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101372734A (en) * 2007-08-24 2009-02-25 宝山钢铁股份有限公司 Martensite stainless steel and manufacturing method thereof
CN101693982A (en) * 2009-09-30 2010-04-14 山西太钢不锈钢股份有限公司 Martensite corrosion-resisting steel plate for cutting tool and manufacture method thereof
CN102363864A (en) * 2011-10-10 2012-02-29 刘群联 Method for manufacturing martensite stainless steel tubes
CN102796963A (en) * 2012-08-17 2012-11-28 山西太钢不锈钢股份有限公司 Martensitic stainless steel rectangular billet continuous casting method
CN113118398A (en) * 2021-04-19 2021-07-16 山西太钢不锈钢股份有限公司 Production method for eliminating large-grain carbide of high-carbon martensitic stainless steel continuous casting slab

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