Method for achieving extreme efficiency of electroslag blank-ingot yield

Abstract

The invention relates to the field of electroslag special metallurgy, in particular to a method for achieving the purpose that the electroslag blank-ingot yield reaches the extreme efficiency. (2) heat top sealing and slagging process optimization design; and (3) residual head self-processing. The method has the beneficial effects that through the equipment function precision guarantee requirement, the heat top sealing process optimization design and the residue self-machining and slagging process design, electroslag residue recycling is completed, and the electroslag blank-ingot yield reaches the maximum efficiency. In the process, waste is reduced, the yield loss of the end tab saw cutting stroke and the cost generated by saw cutting are avoided, and the yield and the production efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of electroslag special metallurgy, and specifically to a method for achieving the ultimate efficiency in the electroslag billet-ingot yield rate. By ensuring the functional accuracy of equipment, optimizing the design of a hot capping process, and designing a self-processing and slag-removing process, the electroslag billet is recycled, thereby achieving the ultimate production efficiency in the electroslag billet-ingot yield rate. Background Art

[0002] The Specialty Metallurgy Operations Area of ​​the Profile Division produces approximately 60 steel grades annually, grouped into approximately 20 series. A significant portion of these grades is produced in small batches, hindering timely delivery of scrap. Due to limitations in the electroslag process and equipment, to protect and recycle the dummy electrodes, each furnace inevitably produces a residual head. This residual head is approximately 20-40 mm thick, 150-800 mm in diameter, and weighs 20-150 kg. This necessity has kept the yield rate of the electroslag process stable at around 98.5%, preventing further improvement.

[0003] Each heat of electroslag produces a scrap, which causes the scrap to pile up and has a great impact on on-site management. Due to the variety of scrap, it can only be dealt with once a month. According to the scrap delivery situation, the small scrap steel varieties are contacted for matching vehicles, which makes it extremely inconvenient to deliver the scrap.

[0004] Each electroslag furnace requires an arc-starting plate of the same steel grade for arc starting. Prior to promoting the recycling of scrap, a piece of material was sawn from the electrode blank for arc starting, while the electroslag scrap was directly discarded. Cutting a piece of material from the electrode blank for the arc-starting plate reduces the yield rate and increases sawing costs. Discarding the scrap also reduces the yield rate and results in cost losses, impacting the yield rate.

[0005] This invention utilizes a heat-sealing process, self-processing of the residual head, and a slag-removing process to achieve the ultimate efficiency in the electroslag billet-to-ingot yield rate. This process reduces residual head waste, avoids yield loss and sawing costs during the arc-starting plate sawing stroke, and ultimately improves yield and production efficiency. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for achieving the ultimate efficiency in the electroslag billet-ingot yield rate in response to the above problems.

[0007] The purpose of the present invention is achieved as follows: a method for achieving the ultimate efficiency of the electroslag billet-ingot yield rate, including the following aspects: (1) Equipment function accuracy assurance: accurately measure the on-site false electrodes one by one, update the false electrode ledger once a quarter, and calibrate the electroslag furnace weighing system on a monthly basis to ensure that the weight fluctuation of the weighing system is no more than 2Kg; (2) Optimization design of hot capping and slag melting process: adjust the hot capping weight to 600±30Kg, combine the ingot shape and running melting speed, increase the power transition parameter, the transition parameter is 10% of the original power, that is, reduce the original power by 10% each time, extend the insulation period to 0.5±0.2 hours, reduce the terminal power to 38±2V / 5±1KA, due to the change of the arc starting plate, increase the electrode descending depth at the initial stage of power transmission on the original basis, and increase the electrode descending depth from the conventional variety to 350±50mm, increase the arc starting current, and reduce Voltage, arc starting current is increased to 6±1KA, and voltage is reduced to 58±2V; (3) Self-processing of the residual head: the surface of the residual head is self-processed, the weld and edge fins are cleaned, the heat-sealed top of the residual head is further processed, and small bumps and oxide scales are polished and removed. The result of further processing is to ensure that the contact surface is flat and free of oxide scales, the residual head and the ingot guide plate are welded, and an ingot guide plate-arc starting plate assembly is made. Aluminum shots are evenly distributed between the residual head and the ingot guide plate. The amount of aluminum shots laid is to ensure that there is no gap between the residual head and the ingot guide plate.

[0008] (2) The operating melting rate is 0.8~0.9D, where D is the diameter of the crystallizer in mm and the melting rate is in kg / h.

[0009] The present invention provides a process and technology for recycling excess scrap, achieving the ultimate efficiency in the electroslag billet-to-ingot yield rate. By ensuring the functional accuracy of the equipment, optimizing the hot-capping process, and designing the excess scrap self-processing and slag-removing process, the present invention achieves the ultimate efficiency in the electroslag billet-to-ingot yield rate. This process reduces excess scrap waste, avoids yield loss during the arc-starting plate sawing stroke, and avoids the costs associated with sawing, thereby improving both the yield rate and production efficiency.

[0010] 1. The present invention designs a feeding and slag reduction process to ensure the reuse of the surplus and achieve the ultimate efficiency in the electroslag billet-ingot yield rate.

[0011] 2. The present invention sets requirements for the functional accuracy of the electroslag furnace equipment to ensure that the thickness of the residual head hits the standard range.

[0012] 3. The present invention realizes the recycling and self-utilization of the electroslag residual heads through the design of surface self-processing and arc-starting material layout of the residual heads.

[0013] 4. The economic benefits can be increased by about 500,000 yuan each year. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] Figure 1 It is the parameter diagram of the existing slag-making process curve.

[0016] Figure 2 It is a parameter diagram of the slag-forming process curve after the design of the present invention. DETAILED DESCRIPTION

[0017] The present invention proposes a process technology method for recycling the residual ends to achieve the ultimate efficiency in the electroslag billet-ingot yield rate. By ensuring the functional accuracy of the equipment, the hot capping process, the residual ends self-processing and the slag reduction process design, the recycling of the electroslag residual ends is completed, and the electroslag billet-ingot yield rate is achieved to achieve the ultimate efficiency.

[0018] 1. Ensure equipment function accuracy: To address the issue of residual head thickness not matching the arc strike plate thickness range, accurately measure each fake electrode on site and update the fake electrode ledger quarterly. Calibrate the electroslag furnace weighing system monthly to ensure weight fluctuations do not exceed 2 kg.

[0019] 2. Optimized Design of Hot Capping and Slag Melting Processes: The existing hot capping process curves were further integrated, the hot capping weight was adjusted, and the power ramp parameters were increased based on the ingot shape and operating melting rate. The holding period was extended, and the terminal power was reduced to the critical point of non-melting steel to ensure a flat surface. Due to changes in the arc striker, the electrode depth was increased during the initial power supply, the arc starting current was increased, the voltage was reduced, and the duration of this stage was extended. This not only prevented slag inclusion defects at the base but also quickly melted the surrounding slag to form an initial molten pool.

[0020] 3. Self-processing of the flange: The flange weld surface had a weld seam and severe surface oxide scale. Furthermore, the smelting end had protrusions scattered throughout due to the reduced melting rate at the end of the heat seal. The lack of a flat surface severely affected the arc starter, rendering it unusable. The improved flange was self-processed to clean the weld seam and edge fins, and the smelting heat seal top was further processed to ensure a flat contact surface. The self-processed flange was welded to the starter plate to create a starter plate-arc starter plate assembly. To address the conductive interface issue, continuous experimentation led to the placement of aluminum shot evenly between the flange and starter plate to ensure uniform conductivity.

[0021] 1. Ensure equipment function accuracy: Address the issue of residual head thickness not matching the arc strike plate thickness range. Precisely measure each fake electrode on-site, and update the fake electrode ledger quarterly. Calibrate the electroslag furnace weighing system monthly to ensure weight fluctuations are ≤2kg.

[0022] 2. Optimized Design of Hot Capping and Slag Melting Processes: Further integrate the existing hot capping process curves, adjust the hot capping weight, and, based on the ingot shape and melting rate, increase the power ramp parameters, extend the holding period, and reduce the terminal power to the critical point where the steel does not melt. This ensures a flat surface on the remaining end. The following table shows the current process parameters.

[0023]

[0024] After adopting the present invention, the slag resistance changes more smoothly, and the generation of residual head convex points is avoided.

[0025] Due to the changes in the arc striking plate, the electrode descending depth is increased at the initial stage of power supply on the original basis, the arc striking current is increased, the voltage is reduced, and the time of this stage is extended. This can not only avoid slag inclusion defects at the base but also quickly melt the surrounding slag to form an initial molten pool.

[0026] The welded surface of the flange had a weld seam and severe surface oxide scale. The smelting end had protrusions scattered throughout due to the reduced melting rate at the end of the heat seal. The lack of a flat surface severely affected the arc starter, rendering it unusable. The improved flange was subjected to surface machining to clean the weld seam and edge fins, and the smelting heat seal top was further machined to ensure a flat contact surface. The on-site machined flange was welded to the starter plate to create a starter plate-arc starter plate assembly. To address the conductive interface issue, continuous experimentation led to the placement of aluminum shot evenly distributed between the flange and starter plate to ensure uniform conductivity. Example

[0027] Special metallurgy operation area of ​​TISCO Profile Division.

[0028] The method of the present invention, in accordance with the requirements for ensuring equipment functional accuracy, optimizing the hot-capping process, and designing the residual head self-processing and slag-removing process, achieves the ultimate efficiency in the yield rate of electroslag billets and ingots. This process reduces residual head waste, avoids yield loss and sawing costs during the arc-starting plate sawing stroke, and improves yield rate and efficiency.

[0029] Specific operations include the following aspects: (1) Equipment function accuracy assurance: accurately measure the on-site fake electrodes one by one, update the fake electrode ledger once a quarter, and calibrate the electric slag furnace weighing system every month to ensure that the weight fluctuation of the weighing system is no more than 2Kg; (2) Optimization design of hot capping and slag melting process: adjust the hot capping weight, the original 540Kg is revised to 600Kg, combined with the ingot shape and running melting speed, the melting speed of Φ700mm electric slag ingot is set to 590Kg / h, increase the power gradient parameter: the process power reduction degree is from 5% of the conventional variety to 10% of the original power of the variety, extend the insulation period, the insulation time of the hot capping stage is extended from 0.3 hours of the conventional variety to 0.5 hours, reduce the terminal power to 38V / 5KA, and reduce it to the critical point of stainless steel. Due to the change of the arc starting plate, the electrode descending depth is increased at the initial stage of power transmission on the original basis, and the electrode descending depth is increased from 250mm of the conventional variety to 350mm, which is improved. High arc starting current, reduced voltage, arc starting current increased from 5KA of conventional varieties to 6KA, voltage reduced from 60V to 58V; (3) Self-processing of the residual head: self-process the surface of the residual head, clean the weld and edge fins, further process the top of the smelting heat seal, that is, the heat seal top of the residual head, and polish and clean possible small bumps and oxide scales). The result of further processing is to ensure that the contact surface is straight (ensure that the surface is flat and free of oxide scales), weld the on-site self-processed residual head and the ingot guide plate, and make an ingot guide plate-arc starting plate assembly. Evenly distribute a portion of aluminum shots between the residual head and the ingot guide plate (the amount of aluminum shots laid is appropriate to ensure that there is no gap between the residual head and the ingot guide plate).

[0030] The above description is only a specific embodiment of the present invention, but the structural features protected by the present invention are not limited thereto. Any changes or modifications made by any technician in this field within the scope of the present invention are included in the patent scope of the present invention.

Claims

1. A method for achieving the ultimate efficiency in the yield rate of electroslag billets and ingots, characterized by: Including the following aspects: (1) Equipment function accuracy guarantee: accurately measure the on-site fake electrodes one by one, update the fake electrode ledger once a quarter, and calibrate the electroslag furnace weighing system monthly to ensure that the weight fluctuation of the weighing system is no more than 2 kg; (2) Optimization design of hot capping and slag reduction process: The weight of hot capping is adjusted to 600±30Kg. In combination with the ingot shape and the running melting speed, the power variation parameter is increased to 10% of the original power, that is, the original power is reduced by 10% each time, and the insulation period is extended to 0.5±0.2 hours. The terminal power is reduced to 38±2V / 5±1KA. Due to the change of the arc starting plate, the electrode descending depth is increased at the initial stage of power transmission on the original basis. The electrode descending depth is increased from the conventional variety to 350±50mm, the arc starting current is increased, and the voltage is reduced. The arc starting current is increased to 6±1KA and the voltage is reduced to 58±2V; (3) Self-processing of the surplus head: The surplus head is self-processed on the surface, the welds and edge fins are cleaned, the heat-sealed top of the surplus head is further processed, and small bumps and oxide scales are polished and removed. The result of further processing is to ensure that the contact surface is flat and free of oxide scales. The surplus head and the ingot guide plate are welded to make an ingot guide plate-arc guide plate assembly. Aluminum shots are evenly distributed between the surplus head and the ingot guide plate. The amount of aluminum shots laid is to ensure that there is no gap between the surplus head and the ingot guide plate.

2. The method for achieving the ultimate efficiency of electroslag billet-ingot yield according to claim 1, characterized in that: (2) The operating melting rate is 0.8~0.9D, where D is the diameter of the crystallizer in mm and the melting rate is in kg / h.

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