CN109750222B - High-performance martensitic stainless steel and manufacturing method of high-flatness plate thereof - Google Patents
High-performance martensitic stainless steel and manufacturing method of high-flatness plate thereof Download PDFInfo
- Publication number
- CN109750222B CN109750222B CN201811210928.7A CN201811210928A CN109750222B CN 109750222 B CN109750222 B CN 109750222B CN 201811210928 A CN201811210928 A CN 201811210928A CN 109750222 B CN109750222 B CN 109750222B
- Authority
- CN
- China
- Prior art keywords
- equal
- stainless steel
- martensitic stainless
- steel
- less
- 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
Links
Images
Classifications
-
- 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
- Y02P10/20—Recycling
Abstract
A high-performance martensitic stainless steel and a manufacturing method of a high-flatness plate thereof are disclosed, wherein the steel comprises the following chemical components in percentage by weight: c: 0.35 to 0.50, Si: 0.05 to 0.35, Mn: 1.60-2.00, P is less than or equal to 0.03, S is less than or equal to 0.01, Cr: 14.5-16.0, N: 0.07 to 0.15, Mo: 0.5-1.5, V: 0.15 to 0.30, Nb: 0.005-0.01, Cu: 0.005-0.02, and Cr +3.3Mo +20N is more than or equal to 18.0, C + N is more than or equal to 0.45, and (Cr + Mo +1.5SI) is more than or equal to 1.25: (20C +20N + Mn) is less than or equal to 1.50, V is more than or equal to 1.5N, and the balance of inevitable impurities and Fe. The martensitic stainless steel manufactured by the invention is finally in a martensite + austenite complex phase structure. The material is quenched by a specific process, and the content of the retained austenite phase is 3 to 12 percent; the quenching hardness HRC is 50.0-55.0; the unevenness of the steel plate or the steel belt is controlled to be less than or equal to 0.86mm/m by a special double-sided water spray and continuous heat treatment process under the tension condition, and high flatness is obtained. The material has high hardness and high toughness, and can be widely used for mechanical, textile and electronic equipment parts.
Description
Technical Field
The invention relates to stainless steel for mechanical parts or electronic equipment and a manufacturing method thereof, in particular to high-performance martensitic stainless steel and a manufacturing method of a high-flatness plate thereof.
Background
The overall size of mechanical parts or electronic equipment in China is 3000 billion yuan, and nearly 70% of the market share is occupied by foreign brands. The ratio of sales of mechanical parts or electronic devices to medicines in developed countries is about 1: 1, and china is only 1: 10.
stainless steel accounts for a large proportion of materials for mechanical parts or electronic equipment, the requirement for a new high-quality and high-performance stainless steel material is extremely urgent in the transformation and upgrading process of the mechanical part or electronic equipment industry, and the mainstream mechanical part or electronic equipment factory also puts forward the requirement for developing the high-quality stainless steel for the mechanical parts or the electronic equipment. Stainless steel materials for mechanical parts or electronic devices mainly include austenitic stainless steels 304L, 316L, 317L, martensitic stainless steels 20Cr13, 30Cr13, 60Cr13 with high carbon content, and the like. Taking the double-joint rongeur made of martensitic stainless steel 3Cr13Mo as an example, the hardness of the double-joint rongeur can reach more than HRC50, the high strength and hardness can avoid the deformation of instruments in the operation process, but the toughness and the corrosion resistance of the material are far lower than those of austenitic stainless steel such as 304, the precipitation of ions caused by insufficient corrosion resistance causes pollution risk to human tissues, the fracture and breakage risk of the rongeur caused by insufficient toughness easily causes harm in the operation. In general, martensitic stainless steels have high hardness and high wear resistance, but have low corrosion resistance and poor toughness.
The martensitic stainless steel is chromium stainless steel and is widely applied to the fields of cutters, measuring tools, water turbine blades and the like which have certain requirements on toughness and corrosion resistance. The medium-low carbon martensitic stainless steel simultaneously has high hardness (45-58 HRC) and good toughness (Charpy V-notch impact energy is more than 30J). However, high strength and high toughness are always a contradiction between the properties of martensitic steels, which increase strength and hardness after heat treatment mainly by adding carbon elements, but increase in carbon content decreases toughness.
Among the strengthening alloying elements of martensitic stainless steels, carbon and nitrogen are the most effective elements for improving strength. Since the addition of carbon tends to form carbon segregation during rolling and heat treatment, which reduces the corrosion resistance of the martensitic stainless steel, the addition of nitrogen is another effective method for improving the mechanical properties of the martensitic stainless steel. The invention makes the martensitic stainless steel with medium and low carbon reach the index of the martensitic stainless steel with high carbon in the aspects of strength and hardness by reasonably controlling nitrogen elements, and the toughness and the corrosion resistance retain the characteristics of the martensitic stainless steel with low carbon, thereby effectively solving the difficult problems of the strength, the toughness, the corrosion resistance and the like of the martensitic stainless steel which are mutually contradictory and difficult to match.
In the related patents searched, Chinese patent No. 103255340 proposes a high strength and toughness hot-formed steel plate and a preparation method thereof in order to overcome the problems of high strength and insufficient toughness after the high strength automobile steel is formed, the steel plate is heated to austenitizing temperature at the speed of 20-100 ℃ for a period of time and then is hot-rolled, austenite grains are refined, the steel plate is quenched to 50-370 ℃ at the speed of 50-120 ℃/s, partial supersaturated martensite and non-transformed retained austenite are obtained, carbon is distributed from martensite to the retained austenite to stabilize the austenite at the tempering temperature of 200-500 ℃ for 5-600s, and finally the steel is quenched to room temperature to obtain a complex phase structure of refined martensite and retained austenite, thereby obtaining the high strength and high toughness steel. The method for realizing the high-strength and high-toughness combination of the complex phase structure by utilizing the quenching and partitioning method is applied to carbon steel, for example, CN103160680 proposes a steel component, and utilizes the quenching and matching technology to obtain the martensite and retained austenite complex phase structure, and the product of strength and elongation of the steel reaches more than 30 GP%; CN103243275 proposes a low-alloy high-strength steel, and a bainite, martensite and austenite complex phase structure is obtained through distribution treatment and tempering treatment, so that good combination of strong plasticity and toughness is achieved; CN103045950 also proposes a low-alloyed low-cost steel, which increases the strength of the steel through rapid quenching and carbon redistribution, ensuring good toughness. The quenching and partitioning method is not applied to stainless steel, in the retrieved patent, CN103614649 provides martensitic stainless steel with carbon content of 0.15-0.4%, nitrogen content of 0-0.12%, chromium content of 13.0-17.0%, nickel content of 0-5%, molybdenum content of 0-2.0%, and the like, a hot rolled plate blank is manufactured by conventional materials, the hot rolled plate blank is heated to 950-1100 ℃ and is kept for 0.5-2 h, then the hot rolled plate blank is air-cooled to 25-200 ℃, then the hot rolled plate blank is heated to 350-500 ℃ and is kept for 10-60 min, the hot rolled plate blank is air-cooled to room temperature, and dispersed residual austenite is introduced into a microstructure of the stainless steel by the quenching-partitioning method, so that the level of strong plasticity of the martensite is greatly improved.
Control of flatness is yet another difficulty with martensitic stainless steels. The main reason is that the conventional martensitic stainless steel requires a heat treatment process of quenching + tempering to obtain high strength and a certain toughness. However, in the quenching and tempering processes, the steel strip or the steel plate is deformed due to the generation or release of stress, so that the high flatness requirement is difficult to achieve, and the requirements of high flatness and high assembly precision of many mechanical or electronic equipment parts cannot be met. The conventional method is to process the quenched workpiece or to adopt constraint in the quenching process, and both methods have certain limitations. The processing after quenching or tempering can not eliminate large deformation, and particularly, a reference surface can not be found under the condition of double-sided deformation; meanwhile, the martensitic stainless steel has high hardness, and is difficult to process and high in cost. Constraining or flattening during quenching and tempering is a conventional way to achieve better flatness, but has the disadvantages of low efficiency, need for specialized equipment, etc.
The invention provides a high-performance martensitic stainless steel and a manufacturing method of a high-flatness plate thereof, which are used for manufacturing a nitrogen-alloyed martensitic stainless steel plate with high flatness, high hardness and certain toughness for mechanical parts or electronic equipment by utilizing a continuous heat treatment mode with tension. The martensitic stainless steel manufactured by the method is finally a martensite + austenite complex phase structure, the material is quenched by a specific process, the content of the residual austenite phase is 3-12%, and fine carbides are promoted to be dispersed and uniformly distributed by microalloying Nb, V, N and the like; the quenching hardness HRC is 50.0-55.0, and the impact energy at room temperature is more than or equal to 30J; the unevenness of the steel plate or the steel belt is controlled to be less than or equal to 0.86mm/m by a special double-sided water spray and continuous heat treatment process under the tension condition, and excellent flatness is obtained, which is far superior to the requirement of less than or equal to 3.2mm/m specified in ASTM A480. The material contains a certain content of residual austenite, so that the material has high hardness and high toughness under the condition of saving tempering, and is used for mechanical, textile and electronic equipment parts.
Disclosure of Invention
The invention aims to provide a high-performance martensitic stainless steel and a manufacturing method of a high-flatness plate thereof, wherein the thickness of the steel plate is 1.0-2.5 mm, the steel plate is finally a martensite + austenite complex phase structure, the material is quenched by a specific process, the content of a residual austenite phase is 3% -12%, and fine carbides are promoted to be dispersed and uniformly distributed by microalloying Nb, V, N and the like; the quenching hardness HRC is 50.0-55.0, and the impact energy at room temperature is more than or equal to 30J; the unevenness of the steel plate or the steel strip is controlled to be less than or equal to 0.86mm/m by a special double-sided water spray and continuous heat treatment process under the tension condition, and excellent flatness is obtained. The material contains a certain content of residual austenite, so that the material has high hardness and high toughness under the condition of saving tempering, and is used for mechanical, textile and electronic equipment parts. The high hardness can meet the requirements of the surgical knife and scissors or electromechanical wear-resistant parts and the like on wear resistance; the Mo and N are alloyed to improve the corrosion resistance, so that the requirements of corrosion resistance and higher safety can be met; more importantly, the special austenite and martensite multiphase structure utilizes the high hardness of martensite and the high toughness of austenite to ensure that the impact energy of the material is more than 30J, has the advantages of high hardness, high strength, excellent corrosion resistance and toughness of the martensitic stainless steel for mechanical parts or electronic equipment, and is a high cost performance material for upgrading materials in the field of mechanical parts or electronic equipment.
On the basis, through a quenching process production line of continuous heat treatment, double-sided water mist cooling is utilized to control the uniform and equivalent cooling strength and cooling speed of two sides of a steel plate or a steel strip, meanwhile, the steel strip or the steel plate is applied with the online tension of 8-16 MPa during quenching and cooling, the quenched material does not need special tempering, and the material obtains high flatness, certain toughness and excellent elasticity, so that the high-flatness steel strip or the open flat steel plate is obtained, the thickness of the steel plate is 1.0-2.5 mm, and the unevenness of the steel plate or the steel strip real object is less than or equal to 0.86mm/m
In order to achieve the purpose, the technical scheme of the invention is as follows:
a high-performance martensitic stainless steel and a manufacturing method of a high-flatness plate thereof are disclosed, wherein the steel comprises the following chemical components in percentage by weight: the steel comprises the following chemical components in percentage by weight: c: 0.35 to 0.50, Si: 0.05 to 0.35, Mn: 1.60-2.00, P is less than or equal to 0.03, S is less than or equal to 0.01, Cr: 14.5-16.0, N: 0.07 to 0.15, Mo: 0.5-1.5, V: 0.15 to 0.30, Nb: 0.005-0.01, Cu: 0.005-0.02, and Cr +3.3Mo +20N is more than or equal to 18.0, C + N is more than or equal to 0.45, and (Cr + Mo +1.5SI) is more than or equal to 1.25: (20C +20N + Mn) is less than or equal to 1.50, V is more than or equal to 1.5N, and the balance of inevitable impurities and Fe.
The high-performance martensitic stainless steel is characterized in that the chemical components of the high-performance martensitic stainless steel meet the condition that Cr +3.3Mo +20N is more than or equal to 18.0, C + N is more than or equal to 0.45, Cr + Mo +1.5Si is more than or equal to 1.25, C +20N + Mn is more than or equal to 1.50 percent, and V is more than or equal to 1.5N.
The manufacturing method of the stainless steel for the mechanical part or the electronic equipment comprises the following steps:
1) smelting according to the components, hot rolling a steel billet or a continuous casting billet with set components to prepare a hot rolled steel plate or a steel strip, wherein the thickness of the steel plate is 1.0-2.5 mm, and annealing by adopting a conventional method;
2) heating the annealed steel strip to 780-830 ℃, rapidly cooling the steel strip to a martensite and austenite two-phase region at a speed of more than 30 ℃/s, performing a special continuous heat treatment process under the conditions of double-sided water spray and tension, controlling the unevenness of the steel plate or the steel strip to be less than or equal to 0.86mm/m and obtaining excellent flatness under the condition of the online tension of 8-16 MPa.
The manufacturing method of the high-flatness high-performance martensitic stainless steel is characterized in that the thickness of the martensitic stainless steel plate is 1.0-2.5 mm, the martensitic and austenitic complex phase structure is finally formed, the content of the residual austenite phase is 3% -12%, and fine carbides are promoted to be dispersed and uniformly distributed through microalloying of Nb, V, N and the like; the quenching hardness HRC is 50.0-55.0, and the impact energy at room temperature is more than or equal to 30J; the unevenness of the steel plate or the steel strip is controlled to be less than or equal to 0.86mm/m by a special double-sided water spray and continuous heat treatment process under the tension condition, and excellent flatness is obtained. The material contains a certain content of residual austenite, so that the material has high hardness and high toughness under the condition of saving tempering, and is used for mechanical, textile and electronic equipment parts.
In the component design of the invention:
carbon: is an important austenitizing element, and a certain carbon content can ensure that a full austenite structure is obtained at high temperature; is an important element for ensuring the hardness after heat treatment, and carbon is an important solid solution strengthening element and precipitation strengthening element; can exist in steel in the form of interstitial atoms, and can complete redistribution through interphase diffusion in the reheating process after quenching to stabilize the residual austenite structure; an excessively high carbon content increases the brittleness on the one hand and also impairs the corrosion resistance on the other hand. In order to achieve the desired effect, the carbon content is required to be 0.35-0.50%, and the carbon is used in combination with nitrogen.
Nitrogen: the nitrogen is an element which can improve the strength and the corrosion resistance of martensitic stainless steel, and the content of the nitrogen is controlled to be 0.07-0.15%, and the content of C + N is more than or equal to 0.45, more than or equal to 1.25 (Cr + Mo +1.5Si) and less than or equal to 1.50 (20C +20N + Mn).
Silicon: mainly used as a deoxidizer added into steel, plays a role in solid solution strengthening, and also has an obvious effect on improving the high-temperature oxidation resistance. However, the high silicon content in steel deteriorates ductility and toughness, and the present invention controls the Si content: 0.05-0.35 percent of (Cr + Mo +1.5Si) and not more than 1.25 percent of (20C +20N + Mn) is not more than 1.50 so as to ensure that the material obtains a structure of martensite and retained austenite after quenching and tempering.
Manganese: manganese is a deoxidizing element and a solid solution strengthening element, the strength of steel can be obviously improved, the manganese can stabilize an austenite phase, a certain amount of austenite phase can be guaranteed to be reserved after quenching and tempering by comprehensively adjusting the element proportion of ferrite to austenite, so that a martensite-austenite complex phase structure is obtained, the content of the martensite-austenite complex phase structure is controlled to be 1.60-2.00% and meets the requirements that (Cr + Mo +1.5Si) is more than or equal to 1.25 and (20C +20N + Mn) is more than or equal to 1.50.
Phosphorus: phosphorus is a harmful element and is therefore reduced as much as possible in accordance with the production control level.
Sulfur: sulfur is also a harmful element, and the formed sulfide not only causes hot shortness but also reduces corrosion resistance, and the content of sulfur is generally controlled to be less than 0.01% to avoid the harmful effect of sulfur.
Chromium: the chromium is an element for improving the corrosion resistance of the stainless steel, but the chromium is a strong ferrite forming element, the austenitizing of the low-carbon martensite steel is difficult when the content is high, the cost is also improved, the chromium content is controlled to be 14.5-16%, and the Cr +3.3Mo +20N is comprehensively controlled to be more than or equal to 18.0 and more than or equal to (Cr + Mo +1.5Si) and more than or equal to (20C +20N + Mn) is more than or equal to 1.50.
Copper: copper is an austenite forming element, a small amount of copper is added, the toughness of the martensitic stainless steel after quenching can be improved, meanwhile, the hot working plasticity of the martensitic stainless steel is improved to a certain extent, the problems of cracks, strip breakage and the like of the martensitic stainless steel during high-temperature hot working are avoided, but a copper-rich phase is easily precipitated during the subsequent quenching and tempering heat treatment processes of the martensitic stainless steel by the Cu element, and the copper-rich phase can make the final use state of the invention become brittle relatively, so that the control of the Cu content is extremely important for the invention, and meanwhile, the experimental research result shows that the Cu content of the invention is controlled as Cu: 0.005-0.02%.
Vanadium: vanadium is a strong nitride forming element, and is very easy to form precipitates such as fine nitrides and the like with nitrogen elements in the hot working or heat treatment process, and the vanadium nitride precipitates in the annealing process can enhance the toughness of a steel mill and refine grains of ferrite in the annealing process due to the annealing heat treatment process adopted when the steel plate is delivered from the steel mill, so that the problems of layering, fracture, deformation failure and the like caused by poor toughness of a steel original plate in the process of processing and forming the steel plate by downstream users are reduced as much as possible. Since vanadium mainly combines with N to form a metal compound, the present invention specifies V: 0.15-0.30% and V is not less than 1.5N.
Niobium: niobium is a strong carbide former, and the addition of niobium to martensitic stainless steels also improves the grain structure and carbide morphology of the as-annealed steel sheet. Niobium can refine the structure of the annealed steel plate and increase the toughness of the annealed steel plate, but niobium is a strong ferrite forming element, if the content is higher, the hardenability of the martensitic stainless steel is reduced, and the difficulty of subsequent quenching heat treatment of a user is increased, so that the invention provides that the Nb: 0.005-0.01 percent.
In the manufacturing process, a steel billet or a continuous casting billet with set components is hot-rolled to form a hot-rolled steel plate or a steel strip, and the hot-rolling heating temperature is 1150-1250 ℃. As shown in the following figure 1, Thermo-Calc phase diagram software calculates the variation of the precipitation content of N in the composition system of the invention with temperature, and as can be seen from the diagram, N element begins to precipitate at about 1250 ℃ in the composition system of the invention, and the precipitation amount becomes larger and larger with the increase of the temperature, therefore, the hot rolling heating temperature of the invention is set between 1150-1250 ℃ to prevent the precipitation of N, so that N is better dissolved in a matrix to improve the mechanical property of the invention.
And heating the annealed steel strip to 780-830 ℃, mainly in order to ensure that the steel can be completely austenitized, and carbon and nitride are fully dissolved in a solid solution. Then rapidly cooling to a martensite and austenite two-phase region at a speed of more than 30 ℃/s, namely cooling the temperature to be between a martensite transformation starting temperature (Ms) and a martensite transformation finishing temperature (Mf) to obtain a martensite and austenite two-phase structure, wherein the calculation method of the Ms temperature is as follows: ms (DEG C) -539 × [ C + N ] -30 × [ Mn ] -12 × [ Cr ] -5.0 × [ Si ], wherein [ C ], [ Si ], [ Mn ], [ Cr ], [ N ] are the weight contents of C, Si, Mn, Cr and N in the martensitic stainless steel, respectively; the calculation method of Mf temperature comprises the following steps: mf (deg.c) ═ Ms-250. The rapid cooling at the speed of more than 30 ℃/s can avoid the precipitation of carbon and nitride in the cooling process.
Meanwhile, in the cooling process, through a special double-sided water spray and continuous heat treatment process under the tension condition, the online tension is 8-16 MPa, the unevenness of the steel plate or the steel strip is controlled to be less than or equal to 0.86mm/m, and excellent flatness is obtained.
Obtaining a martensite and retained austenite multiphase structure at room temperature, wherein the content of the retained austenite phase is 3-12%, and the structure after final heat treatment is shown in figure 2. Research shows that when the proportion content of the retained austenite is about 3-12%, the martensitic stainless steel has the best toughness and the hardness does not obviously decrease under the non-tempering condition.
Compared with the prior art, the invention has the beneficial effects that:
compared with the conventional martensitic stainless steel, the high-performance martensitic stainless steel has more excellent corrosion resistance and mechanical properties, particularly toughness. Finally, the material is a martensite and austenite complex phase structure, the material is quenched by a specific process, the content of the residual austenite phase is 3 to 12 percent, and fine carbides are promoted to be dispersed and uniformly distributed by microalloying Nb, V, N and the like; the quenching hardness HRC is 50.0-55.0, and the impact energy at room temperature is more than or equal to 30J; the unevenness of the steel plate or the steel strip is controlled to be less than or equal to 0.86mm/m by a special double-sided water spray and continuous heat treatment process under the tension condition, and excellent flatness is obtained. The material contains a certain content of residual austenite, so that the material has high hardness and high toughness under the condition of saving tempering, and is used for mechanical, textile and electronic equipment parts. The high hardness can meet the requirements of the surgical knife and scissors or electromechanical wear-resistant parts and the like on wear resistance; the Mo and N are alloyed to improve the corrosion resistance, so that the requirements of corrosion resistance and higher safety can be met; more importantly, the special austenite and martensite multiphase structure utilizes the high hardness of martensite and the high toughness of austenite to ensure that the impact energy of the material is more than 30J, has the advantages of high hardness, high strength, excellent corrosion resistance and toughness of the martensitic stainless steel for mechanical parts or electronic equipment, and is a high cost performance material for upgrading materials in the field of mechanical parts or electronic equipment. Through the continuous heat treatment quenching production line, the problems that in the quenching and tempering processes, due to stress generation or release, a steel strip or a steel plate is deformed, the requirement on high flatness is difficult to achieve, and the requirements on high flatness and high assembly precision of a plurality of mechanical or electronic equipment parts cannot be met are solved. Compared with the processes of quenching, tempering, machining, flattening and the like, the control process provided by the invention has high efficiency and lower cost.
Drawings
FIG. 1 shows the variation of the precipitated content of N with temperature in example C of the present invention.
FIG. 2 shows the structure (residual austenite content 6%) of example C after quenching by a continuous heat treatment at 790 ℃.
Detailed Description
The invention is further illustrated by the following examples and figures. Table 1 shows the composition of the steels of examples of the present invention and comparative examples, and Table 2 shows the heat treatment process and properties of the examples. FIG. 1 shows the structure of a steel sheet of example C of the present invention, which has a thickness of 1.5mm and has a residual austenite content of 6% after quenching by continuous heat treatment at 790 ℃. The martensitic stainless steel with the carbon content of 0.40-0.60 is widely applied to the mechanical part or electronic equipment industry, wherein the comparative example G is 40Cr13, and the comparative example H is 5Cr15 MoV. Taking example 2 as an example, compared with the existing 40Cr13 and 5Cr15MoV such as comparative examples G and H, the nitrogen alloying is adopted on the components, 0.07-0.15% of N is added, on one hand, the N plays an austenitizing role at high temperature, a full austenite phase is ensured at high temperature, and most of the N is converted into a martensite phase after quenching; on the other hand, nitrogen can remarkably improve the corrosion resistance of the material, ensure that Cr +3.3Mo +20N of the material is more than or equal to 18.0, remarkably improve compared with G and H, and show higher corrosion resistance. In particular, when a highly corrosive material such as blood comes into contact with a mechanical component or an electronic device, the improvement of the corrosion resistance ensures higher safety of the material and the device.
On trace element control, V is alloyed by V and ensures that V: n is more than or equal to 1.5, so that a large amount of fine dispersed nitride is formed in the material, and the fine dispersed nitride is an important factor for obtaining excellent toughness of the material; the contents of Cu, Nb and the like are strictly controlled, the precipitation of a Cu-rich phase and a Nb-containing phase is avoided, and the toughness of the material is reduced, so that the Cu content is controlled to be 0.01 and the Nb content is controlled to be 0.008 in the embodiment C and the like, and the medium-temperature brittle phase is prevented from being generated in the material; in terms of structure, through the design of N alloying and the control of the austenite stability of the material, a certain content of residual austenite phase is reserved after quenching, and the characteristic of toughness can be obviously improved by utilizing the residual austenite phase, so that the material has impact performance far superior to that of comparative examples G and H. By the continuous heat treatment quenching process of double-sided water mist cooling and online tension, the material can obtain high hardness and high flatness directly, and the requirements of high-precision assembly or parts are met. The conventional heat treatment process has no control and restriction capability on plate shape, the size of the unevenness is greatly influenced by cooling speed, process, materials and the like, the common value is 5.0mm/m, and the unevenness index which is less than or equal to 0.86mm can be obtained by the materials and the process provided by the invention, so that the process is far superior to the prior process.
In terms of structure, the steel grade designed by the invention obtains a martensite matrix and a small amount of retained austenite after quenching and tempering through component optimization and control, addition of certain nitrogen and matching with control of V, Mn, Nb, Cu, C and the like. If the retained austenite content in example C is 6%, the HRC of the material is 52, and the impact energy is 33J, which has the advantages of high hardness and high toughness, and is an ideal material for mechanical parts or electronic devices.
Claims (5)
1. A martensitic stainless steel comprises the following chemical components in percentage by weight: c: 0.35 to 0.50, Si: 0.05 to 0.35, Mn: 1.60-2.00, P is less than or equal to 0.03, S is less than or equal to 0.01, Cr: 14.5-16.0, N: 0.07 to 0.15, Mo: 0.5-1.5, V: 0.15 to 0.30, Nb: 0.005-0.01, Cu: 0.005-0.02, and Cr +3.3Mo +20N is more than or equal to 18.0, C + N is more than or equal to 0.45, and (Cr + Mo +1.5Si) is more than or equal to 1.25: (20C +20N + Mn) is less than or equal to 1.50, V is more than or equal to 1.5N, and the balance of inevitable impurities and Fe;
the manufacturing method of the martensitic stainless steel comprises the following steps: the method comprises the steps of smelting martensitic stainless steel, annealing after hot working, heating an annealed steel strip to 780-830 ℃, then rapidly cooling the steel strip to a martensite and austenite two-phase region at the speed of more than 30 ℃/s, performing continuous heat treatment under the conditions of double-sided water spray and tension, controlling the online tension to be 8-16 MPa, and controlling the unevenness of a steel plate or the steel strip to be less than or equal to 0.86 mm/m.
2. The martensitic stainless steel according to claim 1, wherein the thickness of the martensitic stainless steel sheet is 1.0-2.5 mm, and the final martensitic + austenitic complex phase structure is obtained, and the content of the retained austenite phase is 3-12%.
3. The martensitic stainless steel according to claim 1 or 2, wherein fine carbides are caused to exhibit a dispersion-uniform distribution by microalloying with V, N or the like and controlling V to be not less than 1.5N.
4. The martensitic stainless steel according to claim 1 or 2, wherein said martensitic stainless steel is finally a martensite + austenite complex phase structure, having both high hardness and high toughness, high hardness: the quenching hardness HRC is 50.0-55.0, and the high toughness is as follows: the impact energy at room temperature is more than or equal to 30J, and the material is used for mechanical, textile and electronic equipment parts.
5. The martensitic stainless steel according to claim 3, wherein said martensitic stainless steel is finally a martensite + austenite complex phase structure, having both high hardness and high toughness, high hardness: the quenching hardness HRC is 50.0-55.0, and the high toughness is as follows: the impact energy at room temperature is more than or equal to 30J, and the material is used for mechanical, textile and electronic equipment parts.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2017113125672 | 2017-12-08 | ||
| CN201711312567 | 2017-12-08 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109750222A CN109750222A (en) | 2019-05-14 |
| CN109750222B true CN109750222B (en) | 2020-12-15 |
Family
ID=66402452
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811210928.7A Active CN109750222B (en) | 2017-12-08 | 2018-10-17 | High-performance martensitic stainless steel and manufacturing method of high-flatness plate thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109750222B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112501491A (en) * | 2019-09-16 | 2021-03-16 | 山特维克材料技术公司 | Martensitic stainless steel alloy |
| US20220235444A1 (en) * | 2019-06-05 | 2022-07-28 | Ab Sandvik Materials Technology | A martensitic stainless alloy |
| CN111778454A (en) * | 2020-08-10 | 2020-10-16 | 常熟理工学院 | Stainless steel for surgical instrument and method for manufacturing same |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3694967B2 (en) * | 1996-04-19 | 2005-09-14 | 住友金属工業株式会社 | Method for producing martensitic stainless steel seamless steel pipe |
| JP3747585B2 (en) * | 1997-08-25 | 2006-02-22 | 大同特殊鋼株式会社 | High hardness martensitic stainless steel with excellent workability and corrosion resistance |
| DE102004051629B4 (en) * | 2004-10-23 | 2006-08-24 | Stahlwerk Ergste Westig Gmbh | Stainless martensitic chrome steel |
| CN102337461B (en) * | 2010-07-23 | 2013-10-16 | 宝山钢铁股份有限公司 | High-hardness martensitic stainless steel and its production method |
| CN103614649B (en) * | 2013-12-06 | 2015-09-30 | 东北大学 | A kind of high-strong toughness high-strength plasticity Martensite Stainless Steel and preparation method thereof |
-
2018
- 2018-10-17 CN CN201811210928.7A patent/CN109750222B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109750222A (en) | 2019-05-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101613831B (en) | Non-hardened and non-tempered high-hardness hot rolled steel, manufacturing method thereof and application thereof | |
| CN103014554B (en) | Low-yield-ratio high-tenacity steel plate and manufacture method thereof | |
| CN102392186B (en) | Manufacturing method of HB500 grade low-manganese wear-resistant steel plate | |
| CN101948987B (en) | Manufacturing method of high-strength and high-toughness steel plate | |
| CN101935810B (en) | Method for manufacturing low-cost super-high intensity steel plate with yield strength of over 960 MPa for wide process operation window | |
| CN101985722A (en) | Pipeline steel plate with low yield ratio, fine grains and high strength and production method thereof | |
| CN109207849B (en) | High-strength high-plasticity 1000 MPa-grade hot rolled steel plate and preparation method thereof | |
| CN109750222B (en) | High-performance martensitic stainless steel and manufacturing method of high-flatness plate thereof | |
| CN107904488B (en) | Super-thick high-strength high-toughness lamellar tearing-resistant Q550 steel plate and manufacturing method thereof | |
| CN103882330A (en) | Non-quenched and tempered steel plate with low yield ratio and super high strength and producing method thereof | |
| CN102691018A (en) | Low-compression ratio super-strength steel plate for ocean engineering and manufacturing method thereof | |
| CN102268607A (en) | Dedicated high-strength steel plate for coal mine hydraulic support and manufacturing method thereof | |
| CN109609729B (en) | Stainless steel plate with 650 MPa-grade yield strength and manufacturing method thereof | |
| CN105200341B (en) | Economical duplex stainless steel with tensile strength of more than 1000MPa and manufacturing method thereof | |
| US8652273B2 (en) | High tensile steel for deep drawing and manufacturing method thereof and high-pressure container produced thereof | |
| CN112877591B (en) | High-strength and high-toughness hardware tool and steel for chain and manufacturing method thereof | |
| CN107557660B (en) | A kind of -50 DEG C of cryogenic steel of normalizing and its manufacturing method | |
| CN102363856A (en) | Rare earth (RE) processed high strength high toughness corrosion resistant steel plate and preparation method thereof | |
| CN111809114B (en) | Plastic die steel with excellent high-temperature strength and preparation method thereof | |
| CN105296866A (en) | Steel for disk blade, production method and disk blade treatment method | |
| CN105220073B (en) | A kind of blade hot-strip and production method and blade processing method | |
| CN111549277B (en) | Martensite wear-resistant steel plate resistant to atmospheric corrosion and manufacturing method thereof | |
| CN115369324B (en) | 38MnVS5 rare earth free cutting hot rolled round steel for automobile and preparation method thereof | |
| CN114045444B (en) | NM 400-grade DQ type martensite wear-resistant steel plate and preparation method thereof | |
| CN109321829A (en) | A kind of yield strength 900MPa grades of stainless steel plates and manufacturing method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |