73 results about "Microalloyed steel" patented technology

The invention discloses a manufacturing method of a high-efficiency and low-cost steel plate for a 345MPa-grade low-temperature pressure vessel, and belongs to the technical field of low-carbon microalloyed steel production. The manufacturing method comprises the steps of molten steel smelting, LF refining, RH vacuum degassing, continuous casting, casting blank heating, rolling, controlled cooling and straightening. The problems that steel plate rolling efficiency is low, rolling resistance is large, and the plate shape is not easy to control are solved, the steel plate is low in cost, high in strength and toughness and high in straightness, and the service safety of the steel plate for the low-temperature pressure container can be guaranteed.

The invention relates to the technical field of low-carbon microalloyed steel production, in particular to economical thin L450M pipeline steel and a method for controlling a banded structure, the steel comprises the following chemical components in percentage by weight: 0.07%-0.09% of C, 0.10%-0.25% of Si, 1.70%-1.80% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.01%-0.02% of Nb, 0.008%-0.015% of Ti, 0.015%-0.04% of Al, 0.05%-0.15% of Cr, 0.003%-0.006% of N and the balance of Fe and inevitable impurities, and the total amount of impurity elements is less than 0.05%; the steel plate produced by the invention has the advantages of low cost, high strength and toughness, low yield ratio and high straightness, and can ensure the service safety of the gas transmission pipeline.

The invention discloses V-N-B microalloyed 550MPa-grade steel for engineering machinery and a preparation method of the V-N-B microalloyed 550MPa-grade steel, and belongs to the technical field of low-carbon microalloyed steel production. The steel comprises the following components in percentage by weight: 0.06%-0.15% of C, 0.2%-0.35% of Si, 1.35%-1.65% of Mn, less than or equal to 0.02% of P, less than or equal to 0.015% of S, 0.01%-0.03% of Nb, 0.015%-0.0250% of Ti, 0.15%-0.25% of Cr, 0.015%-0.045% of Als, 0.05%-0.08% of V, 0.0012%-0.0020% of B, 0.01%-0.025% of N, 0.005%-0.010% of Ca and the balance of Fe and inevitable impurities, the total amount of other impurity elements is less than 0.05%, and the problems of low toughness and plate shape unevenness are solved.

The invention discloses an efficient and low-cost high-strength steel plate for a 1300MPa-grade low-temperature engineering structure and a manufacturing method of the high-strength steel plate, and belongs to the technical field of low-carbon microalloyed steel production. Optimized steelmaking, heating, rolling, pre-straightening, relaxation, controlled cooling, hot straightening and tempering processes are adopted, an ultra-fast cooling and laminar cooling mode is adopted for controlled cooling, chemical components of the steel plate contain Ce, and finally the problems that the 1300MPa-level hot-rolled steel plate with the thickness of 10-50 mm produced through an online cooling process is low in toughness, high in yield ratio, low in flaw detection qualification rate and uneven in plate shape are solved.

The invention relates to the technical field of low-carbon microalloyed steel production, in particular to an efficient rolling low-yield-ratio 345 MPa-grade low-temperature pressure vessel steel plate and a preparation method thereof.The steel plate comprises, by weight, 0.15%-0.18% of C, 0.20%-0.25% of Si, 1.05%-1.55% of Mn, smaller than or equal to 0.020% of P, smaller than or equal to 0.015% of S, 0.01%-0.02% of Nb, 0.015%-0.04% of Al, 0.003%-0.006% of N and the balance Fe and inevitable impurities, and the total amount of impurity elements is smaller than 0.05%; the preparation method of the steel plate comprises the following technological processes of molten steel smelting, external refining and degassing, continuous casting, casting blank heating, controlled rolling, controlled cooling and air cooling to the room temperature. According to the method, the continuous casting billet with the thickness of 170-250 mm is used for efficiently producing the 345 MPa grade steel plate with the thickness of 10-50 mm and the low yield ratio for the low-temperature pressure vessel, the steel plate has the advantages of low cost, high strength and toughness, the low yield ratio and high straightness, and the service safety of the steel plate for the low-temperature pressure vessel can be guaranteed.

The invention relates to the technical field of low-carbon microalloyed steel production, in particular to a high-efficiency rolled thin L450M pipeline steel plate and a manufacturing method thereof, the steel comprises the following chemical components in percentage by weight: 0.05%-0.07% of C, 0.10%-0.25% of Si, 1.45%-1.55% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.05%-0.06% of V, 0.05%-0.10% of Cr, 0.008%-0.020% of Ti, 0.015%-0.04% of Al, 0.005%-0.009% of N and the balance of Fe and inevitable impurities, and the total amount of impurity elements is less than 0.05%; the production process of the steel plate comprises the steps of molten steel smelting, external refining and degassing, continuous casting, casting blank heating, controlled rolling, controlled cooling and air cooling to the room temperature. The method is used for manufacturing the high-strength L450M hot-rolled steel plate for the oil pipeline with the thickness specification being 9-15 mm and the pipe diameter being phi 914 mm or below, the problems that the steel plate rolling efficiency is low, the rolling resistance is large, the steel plate performance uniformity and the plate shape are not easy to control and the like are solved, and the steel plate has the advantages of being low in cost, high in strength and toughness, high in strength, excellent in low-temperature toughness and the like.

The invention discloses a method for calibrating rare earth inclusions in a rare earth microalloyed steel high-temperature laser confocal experiment. The method comprises the following steps: (1) preparing and cutting a rare earth microalloyed steel plate to prepare a cylindrical sample, and pretreating the sample to obtain an experimental steel sample; (2) dividing the to-be-observed surface of the experimental steel sample into n areas and marking; (3) placing the marked experimental steel sample under a scanning electron microscope to observe inclusions; judging an area where the target rare earth inclusion is located according to the mark and determining coordinates of the area; and (4) the experimental steel sample is placed in a high-temperature laser confocal scanning laser microscope, the target rare earth inclusion is found according to the coordinates, and a heating-cooling program is started to melt the experimental steel sample to complete in-situ observation of the target rare earth inclusion. The method can solve the problem that an existing inclusion observation means cannot ensure that original inclusions and changes of the original inclusions cannot be observed when a high-temperature confocal experiment is carried out.

The invention discloses a wide and thin steel plate with excellent low-temperature toughness for a 355MPa-grade low-temperature engineering structure and a manufacturing method of the wide and thin steel plate, and belongs to the technical field of low-carbon microalloyed steel production. The steel plate comprises the following chemical components in percentage by weight: 0.05%-0.08% of C, 0.2%-0.25% of Si, 1.45%-1.55% of Mn, less than or equal to 0.025% of P, less than or equal to 0.015% of S, 0.02%-0.04% of Nb, 0.010%-0.04% of Al, 0.003%-0.006% of N and the balance of Fe and inevitable impurities, and the total amount of other impurity elements is less than 0.05%. The manufacturing method comprises the steps of molten steel smelting, external refining and degassing, continuous casting, slab reheating, rolling and controlled cooling. The steel plate is low in cost, high in strength and toughness and capable of meeting the service safety of the steel plate for the engineering structure under the condition of-60 DEG C.

The invention discloses a thin-gauge pipeline steel plate with low-temperature toughness stable control based on strain design and a manufacturing method of the thin-gauge pipeline steel plate, and belongs to the technical field of low-carbon microalloyed steel production. The method comprises the steps of molten steel smelting, external refining (LF refining), RH vacuum degassing, continuous casting, casting blank heating, controlled rolling, relaxation, heat compensation in a heat preservation box, cooling and air cooling to the room temperature. According to the invention, the low-temperature toughness stability control of the L450M pipeline steel plate for rolling the gas pipeline based on the strain design is realized, wherein the L450M pipeline steel plate is used for rolling the thin specification (9-13mm) and the pipe diameter of the gas pipeline is less than phi 1016mm.

The invention discloses a performance stability improving method based on titanium content and heating temperature cooperative control, and belongs to the technical field of hot continuous rolling steel production. The invention provides a performance stability improving method based on titanium content and heating temperature cooperative control in order to improve the performance stability of high-titanium-content titanium microalloyed steel. According to the method, different slab tapping temperatures and intermediate slab thicknesses are designed according to different Ti contents and finished product thicknesses, the rough / finish rolling temperature and the laminar cooling final cooling temperature are controlled at the same time, through cooperative control over components and the process, the influence of the high titanium content on steel performance fluctuation is avoided, mechanical property fluctuation of finished product steel is reduced, and the quality of the finished product steel is improved. And the fluctuation range of the yield strength and the tensile strength is within + / -30MPa.

The invention provides Nb microalloyed steel with good high-temperature corrosion resistance and a stacking-rotating-gradient cooling hot working method and application of the Nb microalloyed steel, and belongs to the technical field of metal hot working. The Nb microalloyed steel with good high-temperature corrosion resistance comprises the following chemical components in percentage by mass: 0.15 to 0.25 percent of C, 0.2 to 0.3 percent of Si, 0.5 to 0.6 percent of Mn, 0.02 to 0.03 percent of Ni, 0.015 to 0.03 percent of Cr, less than or equal to 0.0025 percent of S, less than or equal to 0.02 percent of P, less than or equal to 0.1 percent of Nb and the balance of Fe. According to the method, the stacking-rotating-gradient cooling hot working technology is adopted, and the Nb microalloying design is combined, so that remarkable refinement of crystal grains is achieved. According to the Nb microalloy low-carbon steel treated by the process, the average grain size of the original austenite can be controlled to be below 30 microns and is obviously reduced compared with that of the conventional process.

This invention discloses a niobium-vanadium-titanium microalloyed seamless steel pipe and its preparation method, belonging to the technical field of seamless steel pipes. The method includes the following steps: S1. Heating, piercing, rolling, and sizing the niobium-vanadium-titanium microalloyed steel pipe to obtain a billet; S2. Annealing and heat-treating the billet to obtain a heat-treated steel pipe; S3. Spraying a coating onto the surface of the heat-treated steel pipe to obtain the niobium-vanadium-titanium microalloyed seamless steel pipe. The niobium-vanadium-titanium microalloyed seamless steel pipe of this invention possesses excellent mechanical properties, meeting the requirements of high-strength operating environments; the surface of the niobium-vanadium-titanium microalloyed seamless steel pipe is corrosion-resistant, making it suitable for high-strength, highly corrosive environments.

Metal strip as an insert for decorative or sealing strips or as edge protection, especially for motor vehicles or control cabinets, which is provided with cut and / or punched openings, wherein the metal strip consists of micro-alloyed steel or multi-phase steel.

This invention relates to an experimental method for detecting the high-temperature plasticity of the edges and corners of microalloyed steel billets, belonging to the technical field of steel process performance testing. The technical solution includes: Experiment A: high-temperature melting test of the billet; Experiment B: high-temperature plasticity test of the billet; Experiment C: bending and straightening plasticity test of the billet; measuring the fracture diameter of the tensile fracture specimen and calculating the reduction of area; based on the experimental results of Experiments B and C at different temperatures, plotting a comparison diagram of the high-temperature plasticity of the billet edges and corners with the test temperature as the X-axis and the reduction of area as the Y-axis, thereby accurately determining whether there is a brittle temperature range in the billet and its edges and corners, and analyzing the high-temperature plasticity of the billet edges and corners based on the experimental results. The beneficial effects of this invention are: simulating the process of rapid cooling and latent heat reheating of the billet edges and corners during actual production, plotting the high-temperature plasticity diagram of the billet edges and corners, accurately detecting and analyzing the high-temperature plasticity of the billet edges and corners, and confirming whether the low-temperature zone of the billet and its edges and corners will cause abnormalities due to excessively low plasticity.

The invention belongs to the technical field of automobile fastener production, and particularly relates to a preparation process of a high-strength screw for an automobile seat. According to the technology, Cr-Mo-Ni-based microalloyed steel is adopted, and a thin-sheet martensite structure containing 10%-15% of stable retained austenite is obtained through VIM-ESR ultra-clean smelting, planetary cross wedge rolling short-process hot working and Q-A-P-C heat treatment including quenching, isothermal deformation, graded isothermal treatment, deep cooling and double tempering. According to the high-safety and environment-friendly automobile seat screw and the manufacturing method thereof, gradient nitriding, the AlCrSiN nanometer multi-layer coating and the graphene hole sealing layer are matched, laser local destressing and lossless full-inspection control are supplemented, and the manufactured screw has the tensile strength larger than or equal to 1350 MPa, the low-temperature impact toughness larger than or equal to 35 J, the salt mist corrosion resistance larger than or equal to 1000 h, the excellent hydrogen embrittlement resistance and the excellent fatigue life, and the high-safety and environment-friendly manufacturing requirements of a new generation of automobile seats are met.

The invention discloses a method for evaluating the corrosion state of microorganisms in real time, high-strength steel and a preparation method. The method for evaluating the corrosion state of the microorganisms in real time comprises the following steps that a microalloyed steel test piece for monitoring is prepared; establishing a microbial corrosion environment: placing the test piece in a culture medium containing microbial flora to form an anaerobic corrosion environment; monitoring a resistance signal in real time: in the corrosion process, continuously measuring resistance values at the two ends of the test piece, and obtaining a resistance-time change curve; and analyzing the corrosion state: evaluating the corrosion stage and uniformity of the material according to the characteristics of the resistance-time change curve.

In order to solve the problems existing in the prior art, common hot rolled steel, carbon manganese steel and low-carbon microalloyed steel are creatively subjected to Al alloying, the difference of free energy of transformation from austenite to ferrite is reduced through addition of the Al element, the free energy is about 140 mol / J, and the content of the Al element in the hot rolled steel is greatly reduced. During thermal deformation, austenite is subjected to phase transformation to induce ferrite phase transformation, so that the difficulty is reduced, and the possibility of deformation-induced ferrite phase transformation is improved. Besides, a certain content of ferrite delta ferrite is obtained within the thermal deformation temperature range (1200-800 DEG C) by adding the Al element, the ferrite delta ferrite is expected to be recrystallized during thermal deformation, fine crystal grains are obtained, and refining of the whole structure is achieved.

The invention discloses a high-strength steel plate for a high-efficiency low-cost 690MPa-grade low-temperature engineering structure and a manufacturing method of the high-strength steel plate, and belongs to the technical field of low-carbon microalloyed steel production. Optimized steelmaking, heating, rolling, controlled cooling and straightening processes are adopted, and finally the problems of low toughness, high yield ratio, low flaw detection qualification rate and plate shape unevenness of the 690MPa-grade hot-rolled steel plate with the thickness of 10-40mm produced by an online cooling process are solved.

The invention provides a microalloy steel multi-mode mechanical property prediction method and device and a readable storage medium, and relates to the technical field of steel performance prediction. The method comprises the following steps: constructing and verifying a phase field model based on thermodynamics and phase field dynamics of a microalloyed steel system to obtain a phase field simulation microstructure image of microalloyed steel; alloy component data and heat treatment process data on a production line are collected, and phase field simulation microscopic structure images and mechanical property indexes corresponding to the alloy component data and the heat treatment process data are obtained; performing standardized preprocessing and sample construction on the phase field simulation microscopic structure image, the alloy component data, the heat treatment process data and the mechanical property indexes, and performing data set division; establishing a multi-modal deep learning model containing an image branch and a numerical branch; carrying out training, evaluation and hyper-parameter optimization based on the training set and the test set, and determining an optimal multi-modal deep learning model; and determining a mechanical property prediction result of the to-be-tested sample based on the optimal multi-modal deep learning model.

The invention discloses a high-strength steel plate for a high-efficiency low-cost 890MPa-grade low-temperature engineering structure and a manufacturing method of the high-strength steel plate, and belongs to the technical field of low-carbon microalloyed steel production. Optimized steelmaking, heating, rolling, pre-straightening, relaxation, controlled cooling and hot straightening processes are adopted, and finally the problems of low toughness, high yield ratio, low flaw detection qualification rate and plate shape unevenness of the 890MPa-grade hot-rolled steel plate with the thickness of 10-30mm produced by an online cooling process are solved.

The invention discloses a thin L450M pipeline steel plate based on strain design and a manufacturing method of the thin L450M pipeline steel plate, and belongs to the technical field of low-carbon microalloyed steel production. The steel comprises the following chemical components in percentage by weight: 0.05%-0.08% of C, 0.15%-0.25% of Si, 1.55%-1.70% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.02%-0.04% of Nb, 0.008%-0.020% of Ti, 0.015%-0.04% of Al, 0.15%-0.25% of Cr, 0.03%-0.06% of Mo, 0.003%-0.006% of N and the balance of Fe and inevitable impurities, and the total amount of other impurity elements is less than 0.05%. The manufacturing method comprises the steps of molten steel smelting, continuous casting, casting blank stacking and slow cooling, casting blank heating, controlled rolling, relaxation and cooling and air cooling to the room temperature. The steel plate has good toughness.

This invention discloses a high-efficiency, low-cost, thin-gauge 1000MPa-grade high-strength steel and its manufacturing method, belonging to the field of low-carbon microalloyed steel production technology. By optimizing the casting, heating, rolling, controlled cooling, and straightening processes, a high-strength, high-toughness, and high-flatness 1000MPa-grade high-strength steel with a thickness of 6–15 mm is finally obtained. This solves the problems of plate warping and poor performance uniformity after online quenching of 1000MPa-grade high-strength steel, and eliminates the need for subsequent offline tempering and straightening treatments to meet the technical requirements of the plate.

This invention relates to a method for controlling the microstructure of microalloyed steel, belonging to the field of metallurgical technology. The method includes the following steps: S1, heating the microalloyed steel; the chemical composition and mass percentage of the microalloyed steel are: C 0.1%-0.2%, Mn 1.3%-1.4%, Si 0.2%-0.3%, Ti 0.009%-0.02%, N 0.004%-0.005%, Nb 0.02%-0.03%, Al 0.01%-0.02%, with the balance being iron and other unavoidable impurities; wherein the mass ratio of Ti to N is (2-4):1; S2, water quenching the microalloyed steel after heating. Through the synergy of composition and process, precise grain control is achieved, effectively solving the problems of limited compression ratio, difficult deformation, and insufficient microstructure uniformity in existing large-size structural steels.

The invention discloses an ultrathin economical X65M pipeline steel plate with excellent low-temperature toughness and a preparation method thereof, and relates to the technical field of low-carbon microalloyed steel production, the ultrathin economical X65M pipeline steel plate comprises 0.04%-0.06% of C, 0.15%-0.25% of Si, 1.45%-1.60% of Mn, less than or equal to 0.015% of P, less than or equal to 0.01% of S, 0.03%-0.05% of Nb, 0.015%-0.025% of Ti, 0.015%-0.04% of Al, 0.003%-0.006% of N, and the balance Fe and inevitable impurities. Through simple component design, the alloy cost is reduced, and the pipeline steel plate with the thickness specification of 6-8.5 mm, low cost, high strength and excellent low-temperature toughness is prepared by regulating and controlling steelmaking, continuous casting and controlled rolling and controlled cooling processes, so that the service safety of a gas transmission pipeline can be ensured.

This invention belongs to the field of seamless steel pipe production technology in the metallurgical industry, specifically relating to a microalloyed seamless steel pipe for nuclear power and its preparation method. The microalloyed seamless steel pipe for nuclear power is composed of the following components by mass fraction: C: 0.19%~0.22%, Si: 0.20%~0.35%, Mn: 1.15%~1.25%, S≤0.008%, P≤0.015%, Cu≤0.1%, Sn≤0.03%, Cr: 0.22%~0.30%, Mo: 0.10%~0.20%, V: 0.06%~0.09%, Nb: 0.050%~0.070%, Ni: 0.2%~0.25%, Al: 0.015%~0.050%, N: 0.008%~0.012%, with the balance being Fe and unavoidable impurities. The microalloyed seamless steel pipe for nuclear power provided by this invention is a microalloyed steel containing Cr, Mo, V, Nb and Ni. It has the advantages of good low-temperature impact toughness, excellent performance after ultra-long simulated welding heat treatment, and low cost.

This invention discloses a high-efficiency, low-cost 890MPa grade high-strength steel plate for low-temperature engineering structures and its manufacturing method, belonging to the field of low-carbon microalloyed steel production technology. By optimizing the steelmaking, heating, rolling, pre-straightening, relaxation, controlled cooling, and hot straightening processes, the problems of low toughness, high yield strength ratio, low flaw detection pass rate, and plate unevenness in the production of 10-30mm thick 890MPa grade hot-rolled steel plates using online cooling processes are ultimately solved.

The invention provides a method for improving the performance uniformity of low-carbon titanium microalloyed steel, which comprises the following steps: preparing a continuous casting billet with qualified components, in percentage by mass, the titanium content in the continuous casting billet is 0.040-0.050%, and the continuous casting billet does not contain B element; the continuous casting billet is heated to a first preset temperature, and heat preservation is conducted for preset time; the continuous casting billet is rolled, the inlet temperature ranges from 950 DEG C to 1150 DEG C, the finish rolling temperature ranges from 820 DEG C to 835 DEG C, at least six passes of rolling are adopted, the reduction rate of the first pass of rolling ranges from 50% to 55%, the reduction rate of the second pass of rolling ranges from 38% to 43%, the reduction rates of the third pass to the fifth pass range from 29% to 32%, and the reduction rate of the sixth pass ranges from 4% to 6%; and after rolling is completed, cooling is conducted at the cooling speed of 20-40 DEG C / s, and then coiling is conducted. On the basis of not adding extra elements, the problem that the mechanical properties of the head, the tail, the edge and the middle of the strip steel are not uniform is solved by combining a rolling process, controlled cooling and coiling temperature control.

The invention discloses a high-strength, tough, and free-cutting medium-carbon microalloy steel. The steel contains Fe and inevitable impurities, and further contains the following chemical elements in the following mass percentages: C: 0.26-0.36%, Si: 0.20-0.70%, Mn: 1.25-1.85%, Cr: 0.15-0.59%, Ni: 0.10-0.25%, Mo: 0.16-0.30%, Cu: 0.04-0.20%, Al: 0.015-0.050%, Nb: 0.003-0.040%, V: 0.10-0.20%, S: 0.015-0.045%, and N: 0.002-0.015%. The steel has an atmospheric corrosion resistance index I of 3.0 or higher. Correspondingly, the present invention also discloses a method for manufacturing the above-mentioned high-strength, tough, and free-cutting medium-carbon microalloyed steel, which comprises the following steps: (1) smelting; (2) casting; (3) heating: controlling the heating temperature to be 1050-1250°C and the holding time to be 3-24 hours; (4) forging or rolling: controlling the final rolling temperature or the final forging temperature to be ≥900°C, and controlling cooling after rolling or forging.

This invention relates to the field of material microstructure control and heat treatment, and particularly to a method for improving the strength and toughness of low-carbon microalloyed steel. The specific process of this method is as follows: (1) adding a small amount of V element to the standard composition of low-carbon microalloyed steel; (2) using a high-temperature diffusion annealing process to reduce or eliminate segregation; (3) obtaining a certain proportion of martensitic structure through multiple critical zone holding and variable-speed quenching, while refining the grain size; (4) controlling the martensite decomposition products through a tempering process to obtain the final microstructure. This invention can effectively improve the final microstructure of low-carbon microalloyed steel and significantly enhance the mechanical properties of the low-carbon microalloyed steel material.

The invention provides a high-carbon brake disc for a racing car and a preparation method of the high-carbon brake disc, and particularly relates to the technical field of brake discs, the high-carbon brake disc comprises a friction disc and a mounting disc which are coaxially and fixedly connected with each other, the friction disc comprises a first friction ring and a second friction ring which are arranged in parallel, and heat dissipation ribs fixedly arranged between the first friction ring and the second friction ring; a ventilation air duct is formed; the first friction ring, the second friction ring and the radiating ribs are all made of high-carbon microalloyed steel, the mounting disc is made of aluminum alloy, and the high-carbon microalloyed steel contains alloy elements of copper, chromium, molybdenum, nickel and niobium. According to the high-carbon brake disc for the racing car and the preparation method of the high-carbon brake disc, the heat fading resistance, the cracking resistance and the heat dissipation performance of the brake disc under the extreme working condition are improved through the special ventilation hole structure design and the innovative high-carbon composite material formula in cooperation with the specific heat treatment technology.