2037results about "Manufacturing converters" patented technology

The invention discloses a distillation SAE and dynamic integration converter steelmaking carbon temperature soft measurement method, which comprises the following steps of: training a teacher model on a large-scale data set of a conventional production working condition, and compressing the model by adopting a knowledge distillation technology; then, a small amount of data from unconventional production working conditions is used for fine tuning to obtain a plurality of expert-type student stacking auto-encoder models SAE; in the prediction stage, a to-be-tested sample is mapped to respective feature space through a plurality of SAEs, and the posterior probability of the sample is calculated in each feature space based on a Gaussian distribution model; and finally, respectively inputting a to-be-measured sample into a plurality of corresponding regression devices to obtain a predicted value, and carrying out weighted fusion on the output of each regression device according to a posterior probability to realize dynamic integration selection of the soft measurement model. The method can effectively adapt to complex data distribution of multi-working-condition changes in converter steelmaking, the carbon temperature prediction precision under the unconventional working condition is improved, and the method has high robustness and engineering practicability.

Provided are a joint regulation method of material flow, energy flow, and carbon emission flow in a long-process steel enterprise, which belongs to a field of intelligent regulation and control technology of electric power system in the steel industry. The method includes: coupling a material-energy characteristic model of each production process of a steel enterprise and a carbon emission model of the steel enterprise, constructing a material flow-energy flow-carbon emission flow coupling model of the long-process steel enterprise, establishing an objective function using a minimize sum of an electricity purchase cost from a superior grid, a park carbon emission cost, and a production raw material cost as an object, and solving and obtaining an optimal operation mode of a joint regulation of the material flow-energy flow-carbon emission flow in the steel enterprise.

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 discloses a converter steelmaking endpoint forecasting method and device and a storage medium, and the method comprises the steps: carrying out the multi-scale importance modeling and graph attention mechanism modeling of the multi-dimensional process characteristics of the current heat, and generating the importance weight and the structure perception weight of each dimension of process characteristics; fusing the importance weight and the structure sensing weight, and multiplying the fused weight with the corresponding dimension process characteristics to generate a characteristic regulation and control vector of the current heat; performing multi-scale convolution operation on the feature regulation and control vector, extracting local mode features under different receptive fields, and outputting a spatial feature vector after the local mode features are enhanced by a self-attention mechanism; a plurality of groups of Transformer encoders are adopted to respectively process the furnace feature sequences with different historical window lengths, and cross-furnace time sequence feature vectors are extracted; and carrying out dimension alignment on the spatial feature vector and the time sequence feature vector, carrying out dimension-by-dimension weighted fusion through a learnable fusion weight, and outputting a steelmaking end point state prediction value of the current heat through a regression prediction network.

The invention discloses a V-B-Ti microalloyed 690 MPa grade steel for engineering machinery, and belongs to the field of metal processing. The steel comprises the following chemical components in percentage by weight: 0.13%-0.17% of C, 0.15%-0.25% of Si, 1.55%-1.7% of Mn, less than or equal to 0.02% of P, less than or equal to 0.015% of S, 0.017%-0.0250% of Ti, 0.1%-0.2% of Cr, 0.015%-0.045% of Als, 0.05%-0.08% of V, 0.0015%-0.0020% of B, 0.005%-0.0095% of N, 3.4%-3.8% of Ti / N 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 steel plate toughness and plate shape unevenness are solved.

The application relates to a method for smelting high-manganese steel in a converter, and belongs to the technical field of steelmaking. The technical problem to be solved by the application is that the manganese content of end-point molten steel produced by a converter in the prior art is low. The technical solution provided by the application for solving the above technical problem is that carbon balls and high-carbon ferromanganese are added in stages according to oxygen supply amount in the smelting process of the converter, when the oxygen supply amount is within 0-10% and 10-80%, 30% and 70% of manganese alloy are respectively added; and when the oxygen supply amount is within 0-10%, 10-50%, 50-80% and 80-100%, 20%, 40%, 30% and 10% of carbonaceous raw materials are respectively added. Compared with the current process for producing high-manganese steel in a converter, the application reduces the investment of alloy heating furnaces and other equipment, meets the production requirements of more varieties of high-manganese steel, improves the metal yield of manganese, shortens the production cycle, and reduces the production cost of high-manganese steel.

The invention relates to the technical field of high-strength steel production, in particular to 780MPa-grade forming-enhanced cold-rolled dual-phase steel and a preparation method thereof.The 780MPa-grade forming-enhanced cold-rolled dual-phase steel comprises the chemical components of 0.09%-0.11% of C, 0.25%-0.45% of Si, 1.9%-2.1% of Mn, smaller than or equal to 0.012% of P, smaller than or equal to 0.006% of S, 0.03%-0.05% of Als, smaller than or equal to 0.005% of N, 0.25%-0.35% of Cr, 0.015%-0.025% of Nb, 0.08%-0.12% of Cu and 0.05%-0.09% of Ni, and the ratio of Nb to Cr is 1: 10-1: 12; ceq is equal to 0.38%-0.42%, and the balance is Fe and impurities; the core objective of the invention is to enable the work hardening index n value to be greater than or equal to 0.24 through component collaborative optimization and process precise regulation and control, so that the industrial pain points of insufficient reaming performance and poor formability of the existing 780MPa-grade cold-rolled dual-phase steel are fundamentally solved, and meanwhile, the alloy cost is reduced, and the manufacturability is improved.

The invention relates to the technical field of metallurgy, in particular to a hot galvanizing low-alloy high-strength steel plate which comprises the following chemical components in percentage by mass: 0.06%-0.08% of C, 0.20%-0.25% of Si, 1.20%-1.35% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.020%-0.060% of Alt, 0.035%-0.050% of Nb, 0.010%-0.020% of Ti, less than or equal to 0.0050% of O, less than or equal to 0.0060% of N and the balance of Fe and inevitable impurities. The contents of C, Si and Mn in the chemical components are controlled, the welding performance of the hot-dip galvanizing low-alloy high-strength steel and the surface quality of a finished product are considered, Nb microalloying is mainly adopted, a proper amount of microalloy element Ti is added to form TiN, austenite grain coarsening is limited in the slab heating and heat preservation process, and fine and dispersed precipitated phases are finally obtained in combination with process control; the hot-dip galvanized low-alloy high-strength steel finished product is good in structure form and excellent in comprehensive performance.

The invention relates to the technical field of ferrous metallurgy, and discloses a converter endpoint carbon content and temperature online prediction method based on multi-modal data. The method comprises the following steps: collecting visual image data, flame spectrum data and blowing process parameter data of furnace mouth flames in the blowing process of a converter to form multi-modal data; accurately positioning and segmenting a flame region by using a target detection and segmentation model, and extracting visual features and spectral features corresponding to the space according to the flame region; the visual features, the spectral features and the process parameters are fused and preprocessed and then input into a pre-trained symbol regression prediction model, and an end point carbon content prediction value and an end point temperature prediction value are obtained; on-line operation guidance information for adjusting the process parameters is generated based on the deviation between the predicted value and the target value and the input parameter sensitivity. According to the method, the end point prediction precision and interpretability are improved, the online control requirement of the converter is met, the end point double hit rate of the converter is effectively improved, and a closed loop from intelligent prediction to intelligent control is achieved.

The invention relates to a wide ultra-thin specification tinplate and a preparation method thereof. A tinplate base material comprises the following chemical components: 0.0010%-0.0014% of C, less than or equal to 0.02% of Si, 0.09%-0.14% of Mn, less than or equal to 0.015% of P, less than or equal to 0.004% of S, 0.0146%-0.0158% of N, 0.0038%-0.0049% of B, 0.015%-0.045% of Alt, 0.0012%-0.0024% of Mg and 0.077%-0.094% of Ti. And the balance of Fe and impurities. The produced wide and ultra-thin tinplate (the thickness is 0.08-0.18 mm, and the width is larger than or equal to 2000 mm) has good structure and performance uniformity, and the alloy cost of the tinplate base material is low; and meanwhile, the problems of quality defects such as strip breakage, holes and bright strips in the cold rolling annealing process of a conventional production process are solved.

The present application relates to the technical field of metallurgy, and particularly relates to a production method of a large-wall-thickness pipeline steel with improved carbon dioxide corrosion resistance and strength and toughness, and specific measures include: (1) controlling the bottom blowing mode and end point requirement in the converter process; (2) controlling the tapping time and replacing the tapping hole opportunity in the tapping process; (3) feeding the CAS aluminum wire and controlling the CAS argon blowing time; (4) controlling the top slag addition amount, heating time and outgoing mode in the LF refining process; (5) controlling the wire feeding parameters, soft blowing time and outgoing requirement of RH in the RH refining process; (6) controlling the precision requirement, casting speed fluctuation and crystallizer liquid level fluctuation of the continuous casting equipment in the continuous casting process to obtain the casting blank. Through controlling the parameters of each process in the smelting and rolling process, the present application realizes the whole-process steel cleanliness control and ladle grain refinement, and further improves the strength, low-temperature toughness, HIC resistance and carbon dioxide corrosion resistance of the large-wall-thickness pipeline steel.

The invention relates to the technical field of steel pipe production, and particularly discloses a production process of a seamless steel pipe special for a high-temperature-resistant and high-pressure-resistant boiler. Under preset process parameters, a clamping mechanism is used for driving a steel billet to rotate and axially feed in, and the steel billet is symmetrically and synchronously beaten through a plurality of hammer heads, so that the steel billet is formed into a round billet; heating and perforating the round billet to obtain a pierced billet; and the pierced billet is sequentially fed into a hammerhead machine and a cold-drawing machine to be subjected to heading and drawing so as to conduct sizing on the steel pipe. The steel pipe is produced by combining a hammering forging mode with a perforating mode, and a plurality of synchronous symmetrical hammers are used for hammering, so that dynamic recrystallization and grain refinement are realized, the compactness of a steel pipe material is improved, and the high-temperature resistance and the pressure resistance of the steel pipe are improved; the circular-arc-shaped hammer head is adopted to be matched with the curvature of the steel billet, stress concentration is avoided, one-time circle forging, punching and sizing of the steel billet are achieved, the advantage of procedure integration is achieved, and the production efficiency is improved.

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 a steelmaking converter carbon brick masonry hoisting device and a use method thereof.The steelmaking converter carbon brick masonry hoisting device cooperates with a steelmaking converter body and a steelmaking converter workshop oxygen lance replacement electric hoist for operation, and comprises a lifting unit, a conveying unit, a construction platform unit and a transportation trolley; the auxiliary function assembly is integrated on all the units to achieve precise limiting, safety protection and automatic control, and the lifting unit is specifically arranged on the outer side area, corresponding to a furnace body gate, of a steelmaking converter platform. The U-shaped limiting assembly is arranged at the top of the lifting unit, the first positioning baffle and the second positioning baffle define the U-shaped groove matched with the transport trolley in width, the length difference value of the first positioning baffle and the second positioning baffle is consistent with the height of the transport trolley, the upper portion and the lower portion of the trolley can be limited, and deviation in the transfer process is avoided; the first buffering protection pad and the second buffering protection pad arranged on the U-shaped limiting assembly can effectively absorb impact force generated when the trolley makes contact with the baffle, and structural deformation and carbon brick collision damage are prevented.

The invention provides a load balance control system of a converter tilting device and a control method thereof, and belongs to the field of converter control. The control system comprises a plurality of motors including a first motor and a second motor; the plurality of feedback encoders, the plurality of controllers and the plurality of frequency converters correspond to the plurality of motors; the motor feedback encoders are arranged on rotating shafts of all the motors and used for obtaining the first rotating speed and the second rotating speed; the master controller is used for generating an integral component and a first control reference value, and the slave controller is used for generating a second control reference value; the frequency converters are in data communication connection, the main frequency converter is used for synchronizing integral components to the driven frequency converter, and the main frequency converter and the driven frequency converter are respectively used for controlling the first motor and the second motor to execute first and second control reference values. The method is mainly used for solving the problems of overload, reverse dragging, unstable control and the like caused by non-uniform load distribution when the converter is driven by multiple motors to tilt, the tilting stability is improved, and the wear rate of equipment is reduced.

The invention discloses an application method of a data model in prediction of converter steelmaking static oxygen supply. The method comprises the following steps: S1, steelmaking converter whole-process data preprocessing; s2, making a data model; s3, deploying the data model online; and S4, the converter L2 process control online system calls the data model online. A data set covering the whole converter steelmaking process is manufactured, a data model is trained on the basis of the data set, the trained data model is deployed on a reasoning server in a containerization mode, a converter L2 system transmits heat characteristic data through an API interface, then an oxygen amount calculation model is remotely called, and on the basis of achieving static oxygen supply amount prediction, the oxygen supply amount of the converter is predicted. And the purpose of improving the prediction precision is achieved.

The present invention relates to the field of metal materials and provides acid-resistant pipeline steel and a manufacturing method therefor. The chemical components of the acid-resistant pipeline steel comprise, in percentage by weight: 0.02-0.06% of C, 0.10-0.30% of Si, 0.80-1.10% of Mn, 0.02-0.08% of Nb, 0.06-0.12% of V, 0.20-0.30% of Ni, Mo ≤ 0.08%, 0.03-0.06% of Al, 0.0005-0.0030% of Ca, P ≤ 0.008%, S ≤ 0.002%, 0.004-0.006% of [N], [O] ≤ 0.002%, [H] ≤ 0.0015%, B ≤ 0.0008%, and the balance being Fe and inevitable impurities. The acid-resistant pipeline steel is obtained by sequentially carrying out KR pre-desulfurization, BOF top-bottom combined blowing smelting, LF refining, RH refining, continuous casting with stack cooling, heating, steel rolling, rapid water cooling, and heat treatment on blast furnace molten iron. By means of the synergistic effect of composition design and process optimization, the present invention solves the problems of poor low-temperature drop-weight tear test performance and large strength variation across the same plate in acid-resistant pipeline steel.

The invention belongs to the technical field of steelmaking, and particularly relates to a process for smelting molten steel by adopting an RE-Si-Fe composite deoxidizer, which comprises the following steps: adding pretreated molten iron into a converter for smelting, and adding the RE-Si-Fe composite deoxidizer in the tapping process of the converter; and steel ladle top slag modification is carried out after steel tapping is completed. The RE-Si-Fe composite deoxidizer added in the converter tapping process can simultaneously exert the deoxidation and microalloying effects of rare earth in steel, stable reaction and retention of the rare earth in the steel are achieved while a good deoxidation effect is achieved, and inclusion control is facilitated. And the conventional calcium treatment operation for modifying the aluminum deoxidation product can be completely canceled, so that the production cost and the production treatment time of the smelting process are further reduced.

The invention discloses a method for improving coal gas recovery quality through dry dedusting, which comprises the following steps: S1, setting and dynamically adjusting the rotating speed parameter of a fan aiming at each stage of converter smelting, and controlling the fan to operate according to different operation links and blowing time periods in the smelting process and the set rotating speed parameter and time parameter; s2, raw material preparation and parameter regulation and control are carried out, components, temperature and charging quantity parameters of molten iron entering a furnace are set and controlled, and meanwhile the charging quantity and charging mode parameters of waste steel are set and regulated and controlled; s3, according to the silicon element content of the molten iron, correspondingly setting and controlling a furnace mouth micro differential pressure parameter; s4, in the main blowing smelting stage, oxygen supply flow parameters are matched, set and controlled according to the silicon element content of the molten iron; s5, auxiliary control parameter setting and measures are implemented, wherein the auxiliary control parameters comprise a smoke hood operation control parameter, an evaporative cooling system medium adjustment parameter, a gas recovery program optimization parameter and a fan rotating speed control mode configuration parameter; and S6, after smelting is finished, the recovery average value of CO in the coal gas is recorded. According to the method for improving the coal gas recovery quality through dry dedusting, the average CO value of coal gas recovery is larger than or equal to 55%, the heat value is high, the coal gas quality is stably improved during continuous production of a converter, and the cost reduction and efficiency improvement effects are obvious.

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 utility model relates to a converter mouth purging device in the converter tapping process, and belongs to the technical field of converter steelmaking in the metallurgical industry. According to the technical scheme, one end of a large rotating arm (4) is rotationally connected to a stand column (1) through a rotating body and a rotating body support, the other end of the large rotating arm (4) is rotationally connected with one end of a small rotating arm (13) through the rotating body and the rotating body support, a universal support (11) is rotationally connected to the other end of the small rotating arm (13) through the rotating body, a positioning sleeve (10) is arranged on the universal support (11), and the positioning sleeve (10) is connected with the stand column (1). The stainless steel purging pipe (7) penetrates through the positioning sleeve (10), one end of the stainless steel purging pipe (7) is connected with the nozzle (5), the other end of the stainless steel purging pipe (7) is connected with the elbow (14) and the control handle (15), and the elbow (14) is connected with the metal hose (16) through the quick connector (17). The device has the beneficial effects that bonded slag or steel at the converter mouth can be automatically, safely and efficiently cleaned, and the normal operation of the converter is ensured.

The invention discloses wear-corrosion-resistant high-strength steel for a power transmission tower and a preparation method thereof, and belongs to the technical field of metal materials. The wear-corrosion-resistant high-strength steel for the power transmission tower provided by the invention has good corrosion resistance and wear resistance, has excellent wear resistance in a soil environment of sulfate ions with the concentration of 300 mg / kg-50000 mg / kg and chloride ions with the concentration of 500 mg / kg-10000 mg / kg, and meets various environmental performance requirements of an acid soil environment, an atmospheric corrosion environment and the like. In an acid soil environment, the corrosion resistance is more than 8 times that of plain carbon steel, and the relative corrosion rate is lower than 10%; compared with Q355B, the corrosion rate of atmospheric corrosion resistance is lower than 40%, and the abrasive wear rate is 26.5%-28.0%; and through reasonable matching of corrosion-resistant elements, the requirements of corrosion resistance in various environments are met. The yield strength is 775 MPa-805 MPa, the tensile strength is 952 MPa-985 MPa, the percentage elongation after fracture A50 is larger than or equal to 28%, the low-temperature impact toughness at the temperature of-60 DEG C is larger than or equal to 260 J, meanwhile, the forming performance is excellent, and the 180-degree cold bending requirements that d is equal to 1.0 a are met.

A slag barrier plate for a side-blown melting furnace with a melting bath, characterized in that it comprises: a slag barrier unit (1) with a plate body (11) for holding back molten slag; a heat dissipation unit (2) comprising: a cooling water jacket (21) extending through the interior of the plate body (11) to continuously introduce cooling medium into the plate body (11) to lower its temperature; a distributor arrangement (22) arranged at the end of the cooling water jacket (21) to introduce the cooling medium into the cooling water jacket (21).

The invention discloses a rare earth high-performance EH40 marine steel plate and a production method thereof. The rare earth high-performance EH40 marine steel plate provided by the invention comprises the following chemical components in percentage by mass: 0.06 to 0.09 percent of C, 0.20 to 0.30 percent of Si, 1.45 to 1.60 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.035 to 0.050 percent of Nb, 0.035 to 0.050 percent of V, 0.012 to 0.022 percent of Ti, 0.020 to 0.035 percent of Als, 0.0005 to 0.0020 percent of rare earth Ce, less than or equal to 0.40 percent of CEV, less than or equal to 0.20 percent of Pcm and the balance of Fe and inevitable impurities. The performance meets the requirements that the yield strength is larger than or equal to 390 MPa, the tensile strength is 510-660 MPa, the percentage elongation after fracture is larger than or equal to 20%, and the impact energy at the temperature of minus 40 DEG C is larger than or equal to 270

A tilting device and a melt processing method are provided that can stably discharge a melt from a container in an accurate amount. [Solution] The present invention provides a tilting device that includes a main body, a mounting section disposed on top of the main body so that a container can be placed thereon, and a tilting section that is disposed on the main body so that the mounting section can be tilted, is connected to the mounting section, and has a reducer, and that can discharge molten material from the container, and includes the steps of placing the container containing the molten material on the tilting device, preparing a transport cart below the container that contains a molten material different from the molten material, tilting the container with the tilting device, slowing down the tilting speed of the container, and discharging the molten material from the container and loading it into the transport cart. the step of tilting the container includes a step of rotating a driver of the tilting device, a step of rotating a tilting shaft member of the tilting device with the driver, and a step of tilting the container using the tilting shaft member; and the step of decelerating the tilting speed of the container includes a step of primarily decelerating the rotational speed of a rotational force generated in the driver, a step of secondarily decelerating the rotational speed of the rotational force, and a step of transmitting the rotational force, the rotational speed of which has been secondarily decelerated, to the tilting shaft member.

The invention relates to the technical field of metallurgy, in particular to 420MPa-grade low-alloy high-strength steel which comprises the following chemical components in percentage by mass: 0.06%-0.08% of C, 0.10%-0.15% of Si, 0.90%-1.25% of Mn, less than or equal to 0.025% of P, less than or equal to 0.010% of S, 0.015%-0.060% of Alt, less than or equal to 0.0060% of O, less than or equal to 0.0060% of N, 0.0010%-0.0040% of Ca and at least one microalloy element of 0.035%-0.055% of Nb, 0.010%-0.035% of Ti and 0.005%-0.015% of V. The addition amount of the microalloy elements meets the condition that Nb + Ti + V is more than or equal to 0.04% and less than or equal to 0.08%. If a microalloy element Ti is added, Ti / (C + N) is larger than or equal to 0.2 and smaller than or equal to 0.6, the stoichiometric ratio of Ti to N is 1.6-2.5, and the balance is Fe and inevitable impurities. The common cold-rolled or hot-galvanized low-alloy high-strength steel plate is produced by adopting the same components, so that the production organization difficulty and the process cost are reduced.

The invention belongs to the technical field of steelmaking, and relates to a method for controlling large-size inclusions in silicon-aluminum deoxidized steel. Converter tapping adopts a silicon-aluminum deoxidation process, after tapping, high-oxidability slag is removed by adopting a slagging-off process, and then high-reducibility premelting refining slag is added for re-slagging, so that the slag (TFe + MnO) at most of the refining moments is maintained within 0.50%; in the refining process, the stirring strength is controlled to control the desulfurization rate of the refining slag within 50%, so that the slag entrapment degree of the refining slag is reduced to the maximum extent; two iron sheets with the thickness being 2 mm are placed on the liquid level of the slag in advance before RH vacuum treatment, it is guaranteed that the slag is prevented from being drawn into the dip pipe in the process that the dip pipe is inserted into the molten steel, soft blowing is conducted for 10-15 min after RH vacuum treatment, then argon is closed, and the molten steel is subjected to standing for 20-30 min. By the adoption of the smelting process, the product rejection rate caused by large-size inclusions is reduced to be within 2%.

The invention relates to the technical field of research and development of low-temperature bolt steel, and discloses a low-temperature impact performance control process for low-temperature bolt steel. Comprising the steps that S1, in the steelmaking refining stage, purity and uniformity control is conducted, S2, casting blank homogenization treatment is conducted, stress relief and structure regulation are conducted, S3, a heat treatment core process is conducted, structure and toughness balance regulation is conducted, and S4, online detection and dynamic feedback are conducted, and performance stability is guaranteed. By accurately controlling the element proportion of carbon (C), silicon (Si), manganese (Mn), chromium (Cr) and molybdenum (Mo) in steel and combining with an optimized heat treatment process (such as 860 DEG C oil quenching and 640-650 DEG C high-temperature tempering, and the heat preservation time is prolonged to 120 minutes or more), the V-shaped notch impact energy of the material in the environment of-101 DEG C stably reaches 35 J or more, the impact energy of part of samples can reach 50 J or more, and the impact energy of the part of samples can reach 50 J or more. The problem that the low-temperature impact performance is insufficient after wire hardening and tempering is thoroughly solved, and it is ensured that the brittle failure resistance of the bolt is remarkably improved in the ultralow-temperature environment.

The invention discloses a refining calcium-free treatment process, and belongs to the technical field of refining and smelting of high-carbon aluminum-containing steel. According to the method, various smelting parameters of the whole steelmaking process are adjusted, sulfur entering a converter is guaranteed in a desulfurization area, tapping carbon, tapping temperature, in-place refining component hit rate, deoxidation degree and tapping phosphorus difference are guaranteed in a converter area, refining treatment time, white slag protection time and soft blowing time are guaranteed in a refining area, the content of Al2O3 in molten steel is reduced, the purity of the molten steel is guaranteed, and the quality of the molten steel is improved. Molten steel calcium-free treatment is achieved, and the quality of molten steel is improved.

The invention relates to the technical field of steelmaking production, in particular to a method for judging steelmaking splashing and drying by combining furnace gas and audio frequency, which comprises the following steps: continuously calculating the difference value between the current gas value 1 and the gas value before the set time to obtain the slope; continuously calculating the difference value between the current gas value 2 and the gas value before the set time so as to obtain the slope; the converter noise audio is divided into an audio dry-returning area, an audio splashing area, an audio normal area, a high-order audio value splashing area and a low-order audio value dry-returning area; and S5, splashing drying and trend determination. The method has the advantages that the real-time data of the array queue CO and the array queue CO2 are stored and analyzed, the splashing and drying conditions in the steelmaking process can be accurately judged, the judgment mode based on quantitative data overcomes the defect of inaccuracy of traditional judgment only based on artificial experience or a single audio system, and the judgment efficiency is improved. And the phenomena of splashing and drying caused by misjudgment are effectively reduced.