Electric furnace steelman, 2025TheoryExamination libraryFirst, the judgement (correctly “sniff” and wrongly “x”) 1. The basic principle for steel refining in electric furnaces is to use electric energy to convert thermal energy to melt metal furnaces. (√) answer resolution: the statement is correct because the furnace steel is mainly produced by generating an arc between the electrodes and the furnace, converting the electrical energy into thermal energy, thereby melting the metal furnace. Sulphur in steel causes thermal flaring of steel, so sulphur is a harmful element and its content should be minimized during steel refining. (√) analysis of the answer: sulphur exists in steel in the form of fes, fes forms a low-melting point crystal, which, in heat processing, results in thermal flaring of steel, which seriously affects the quality of steel, so that steel is refined to minimize the sulphur content. The main tasks during the oxidation period are decarbonization, dephosphony, gas removal and mixing, and warming. (h) analysis of the answer: the oxidation period is an important stage in the steel production of electric furnaces, e. G. By blowing oxygen into steel fluids, which produces carbon monoxide gases for decarbonization purposes; phosphorus produces oxidation into slags under oxidation conditions and is removed; at the same time, high temperature and oxidation removes gases and clamps in steel fluids and increases the temperature of steel fluids. Electro-depletion is not related to current density. (x) answer resolution: ecd is closely related to current density. The higher the current density, the higher the temperature on the surface of the electrode, the higher the consumption of the electrodes, such as oxidation, upliftment etc. 5. The mobility of steel water only relates to the temperature of steel water. (x) answer resolution: the flow of steel water is related not only to temperature but also to the composition of steel water, impurities, etc. For example, steel containing more oxidizing mixes reduces the mobility of steel water. The choice question (one or more correct answers to each question) 1. The stoves commonly used in electric furnace steel are (abcd) a. Waste steel b. Raw iron c. Iron alloy d. Ore solution: waste steel is the main furnace in electric furnaces; raw iron can adjust the composition of steel and increase the heat of steel fluids; iron alloy can be used to adjust the chemical composition of steel; ore can be used as an oxidant and a slag agent, etc., in steel furnaces. 2. The following are steel slag formulations: (abc) a. Limeb. Fray c. White cloud d. Coke solution: lime is the most commonly used slag agent that reacts with impurities such as sulphur and phosphorus into the slag; plume can reduce the slag melting point and increase the flow of slag; plumstone can increase the slag alkalinity and improve slag performance; and coke is mainly used as a fuel and a retroactive agent and is not a slag agent. The dephosphorus reaction in the furnace is (b)a. Thermal reaction b. Thermal reaction c. Thermal reaction c. Cannot determine the solution: the dephosphorus reaction is the process of producing phosphorus quinoxide in the steel fluid in combination with oxygen, and the reaction to slags such as lime, which is thermal reaction. Common gas impurities in steel are (abc)a. Hydrogen b. Oxygen c. Nitrogen d. Co2 resolution: steel absorbs gases such as hydrogen, oxygen and nitrogen during smelting and injection, which affect the performance of steel; co2 is generally not present in impurities. Among the measures that could be taken to improve the heat efficiency of electric furnaces are (abcd)a. Optimizing the furnace structure b. Using foam technology c. Strengthening temperature protection in furnaces d. Reasonable control of power supply systems: optimizing the furnace structure can reduce heat dispersion; foam technology can allow the arc to be buried in sludge and increase thermal efficiency; improving the temperature of furnaces can reduce heat dispersion from the oven to the surrounding environment; and rational control systems can make electricity more efficient into heat for use in melting furnaces. Iii. Question 1. The main equipment for steel fabrication in electric furnaces consists of the furnace body, (the electrode system), (power supply system), (diversion system) etc. The answer is: the electrode system provides thermal energy for the generation of arcs; the power system provides electrical power for the furnaces; the tilt system is used for the dumping of the furnaces, making steel, etc. 2. Phosphorus in steel produces (cooled) steel phenomena and reduces steel (plasticity) and (resistence). The answer is: phosphorus increases the flaccidness of steel at low temperatures, leads to a chilling phenomenon, thus reducing the plasticity and resilience of steel. The primary purpose of decarbonization during the oxidation period is (the removal of carbon from steel to the specified content), (the removal of gas and mixing), (the uniform composition and temperature of steel liquids). The answer is: decarbonization is to adjust the carbon content of the steel to the appropriate range; at the same time, carbon monoxide bubbles generated during decarbonization can carry gas and compress up to remove them; and the mixing of steel fluids allows for even composition and temperature. The main function of steel slags in electric furnaces is (the removal of impurities such as sulphur, phosphorus, etc.), (the protection of steel fluids) and (the reduction of heat losses). The solution is: the slag can react to impurities such as sulphur, phosphorus and so on; covering the surface of the steel liquid prevents the exposure of the steel fluid to the air from being oxidized; it also reduces the heat loss of the steel fluid. Thermal processes for the treatment of steel include, inter alia, (repulsion), (fire), (fire), (flammation) and (backfire). The answer is: the retreating fire is a process of heating the steel to the right temperature for a certain period of time and then slowly cooling the heat; it is heating the steel to the critical temperature and cooling in the air after the right time; it is heating the steel to the critical temperature and cooling quickly after a certain time; it is heating the steel after the fire to a certain temperature below the critical temperature and cooling after a certain time. Question 1. Briefly describe the basic process processes for ironing in electric furnaces. Response: the basic process process for steel manufacture in electric furnaces typically consists of the following stages: (1) assembly: the filling of a percentage of the stoves, such as scrap steel and raw iron. When filling, care is taken of the size and distribution of the furnace to ensure good conductive and melting conditions. (ii) melting period: electric power creates an arc between the electrodes and the furnace, transforms the electrical energy into thermal energy and gradually melts the furnace. In the process of melting, appropriate oxygen can be blown to aid the melting, increasing the rate of melting. (3) oxidization period: oxidation period when the furnace is essentially melted. Blow oxygen into steel liquids, allowing carbon oxidation in steel fluids to generate carbon monoxide gases, dephosphorus, gas removal and mixing, and increase the temperature of steel fluids. (4) reversion: at the end of the oxidation period. Deoxygent steel fluids with deoxygents, accompanied by slag agent slag reduction, further removal of impurities such as sulphur, and adjustment of steel liquid composition and temperature. (5) out of steel: when the composition and temperature of the liquid meets the requirements, the tilt furnace pours the liquid into the pack and performs steel operations. Why control the carbon content of steel? Response: controlling the carbon content of steel is important for the following main reasons: (1) impact on steel strength and hardness: carbon is one of the main elements influencing steel strength and hardness. In general, as carbon levels increase, steel strength and hardness increase, but plasticity and resilience decrease. By controlling the carbon content, steel of varying strength and hardness is available to meet the needs of various engineering and industrial applications. (2) effects on the welding performance of steel: a high carbon content makes the welding performance of steel less effective and can easily produce defects such as cracks during welding. Therefore, for steels that require welding processing, carbon content needs to be strictly controlled. (3) impact on steel resistance: excessive carbon content reduces steel resistance. In a number of cases where the requirements for corrosivity are high, such as marine engineering, chemical equipment, etc., there is a need to control the carbon content of steel. (4) effects on the processing performance of steel: the processing performance of steel may vary depending on the carbon content. For example, low-carbon steels are more plastic and resilient, with ease of cold and heat processing, while high-carbon steels are more rigid and relatively difficult to process. 3. Briefly describe the role of foam slag in steel in electric furnaces. Response: foams in electric furnace steels play the following important roles: (1) increase heat efficiency: they can embed electric arcs, increase the flow of heat from the arcs to steel fluids, reduce thermal radiation of the arcs to the furnace walls and roofs, thereby increasing the efficiency of electrical power and reducing electricity consumption. (2) protection of furnace liner: foams are covered on the surface of the steel liquid, which reduces the brushing and erosion of the steel liner, prolongs the useful life of the liner and reduces production costs. (3) promotion of chemical reactions: slag has a large surface area, increases the area of exposure between steel fluids and slags, facilitates chemical reactions such as dephosphorus and desulphurization, and improves steel refining. (4) noise reduction and dust reduction: slag absorbs arc noise while reducing arc mixing with steel fluids and reducing the splattering of metal and slag in steel fluids, thereby reducing dust generation and improving the working environment. Question 1. Calculate how much kg of scrap steel (0. 1% of carbon in scrap steel) needs to be added to adjust the carbon content, assuming a 10% burn rate of carbon in the smelting process. Solve: x ton of scrap steel required for installation. The quality of raw carbon in the furnace is 100 x 2. 0% = 2 % carbon in steel liquids at the time of steel production: (100 + x) x 0. 2% carbon burn in smelting is: 2 x 10 = 0. 2 % carbon in scrap steel is available on the basis of carbon quality: 2 - 0. 2 + x 0. 1 = (100 + x) x 0. 1 = 0. 2 1. 8 + 0. 002 x 0. 002 x-0. 001 x = 1. 8 - 0. 2 - 0. 20. 0001 x = 1. 6 = 1600 kg response: 1. 6 million kg of waste steel needs to be added to adjust the carbon content。2. In an electric furnace, phosphorus content is 0. 05%, target phosphorus is 0. 01% and dephosphorus efficiency is known to be 80%, and several dephosphorus operations are required to reach the target phosphorus content. Solving: need to set up n times
