The characteristics of arc plasma are: high temperature, concentrated energy, adjustable power, controllable atmosphere, no electrode loss, low noise, simple equipment, high electrothermal conversion efficiency, etc. It is a special clean high temperature heat source. The arc plasma torch fundamentally eliminates the graphite electrode, and can artificially control the plasma atmosphere to an oxidizing atmosphere, a reducing atmosphere or an inert atmosphere, and the atmosphere is pure, providing an excellent environment for high-quality smelting, and is the most smelting of special alloy materials. One of the ideal heat sources is suitable for multi-variety, small batch, flexible production characteristics.
Wan Shude et al. of the University of Science and Technology of China applied its practical application to material smelting production, showing the broad application prospect of this technology in the field of metallurgy.
I. Ultra-low carbon stainless steel plasma smelting
The smelting system directly adds a plasma heater above the 1 t medium frequency induction furnace steel ladle to form an intermediate frequency induction plasma melting furnace. In 1992, a company in Wuxi used to produce ultra-low carbon stainless steel. The medium frequency induction furnace is used to melt the solid raw material charged into the furnace, and is subjected to plasma smelting after the raw material is melted. The plasma torch center passes through the protective gas Ar to protect the cathode from oxidation; the ambient O2 gas is used as a reaction material. Oxygen is present in an ion or atomic state in the discharge forming plasma and has a very strong oxidizing property. Stir the molten steel by bottom blowing Ar. The carbon in the molten steel is oxidized in a high temperature oxygen plasma to achieve the purpose of purification. The smelting effect is obvious, and the obtained stainless steel products have w(C) ≤ 4×10-6. The product is used to produce valve bodies with special requirements.
2. Continuous casting tundish plasma heating
Under the conventional process, due to the long continuous casting production process and the large temperature drop of the molten steel, in order to ensure the continuous casting can be carried out normally, it is necessary to have a high degree of tapping superheat, thereby increasing the iron loss and sacrificing the furnace age. At the same time, due to the continuous temperature of the molten steel during the pouring process Changes, it is difficult to ensure the quality of the billet is stable. Continuous casting tundish plasma heating provides the best means of solving the above problems. The use of plasma heating system for tundish steel water heating can achieve near constant temperature casting and reduce the superheat of tapping steel. The benefits are as follows: 1. Low superheat casting increases the pouring speed and thus improves the pouring efficiency; 2. Approximate constant temperature Pouring greatly improves the quality of the billet and reduces the formation of segregation and columnar crystals. 3. Reduces the superheat of the tapping steel, reduces the iron loss, increases the furnace age, reduces the cost and improves the productivity. 4. Reduces the residual amount of tundish steel and reduces the low temperature reflow rate; Reduce the gamble of the mouth. The self-developed 1000 kW continuous casting tundish plasma heating system was successfully used in 1994 for the heating of tundish steel in a continuous casting machine of Maanshan Iron and Steel Co., Ltd.
High-strength high heat-resistant steel plasma melting
In 2003, the self-developed 500 kW high-strength, high-heat-resistant, high-Ni alloy steel plasma melting system was put into production in a Shanghai company. The production process is as follows: (1) The raw material is melted and smelted for 4 h with a 2 t intermediate frequency furnace, and the alloy ratio is sampled and adjusted; (2) the molten steel is poured into a hot ladle and hoisted to a vertical continuous casting production station. The smelting is continued for 20 min with Ar arc plasma. In the process, special alloy material or slag is added. The high temperature plasma melts the slag on the surface of the molten steel, and then the bottom temperature is mixed to make the molten steel temperature and the alloy material composition uniform. The material obtained by this special smelting method has high strength and high heat resistance. The products have been used in China's largest water conservancy project dam ship lock rails, large ship propellers, turbine engine impeller blades and so on.
Wan Shude et al. of the University of Science and Technology of China applied its practical application to material smelting production, showing the broad application prospect of this technology in the field of metallurgy.
I. Ultra-low carbon stainless steel plasma smelting
The smelting system directly adds a plasma heater above the 1 t medium frequency induction furnace steel ladle to form an intermediate frequency induction plasma melting furnace. In 1992, a company in Wuxi used to produce ultra-low carbon stainless steel. The medium frequency induction furnace is used to melt the solid raw material charged into the furnace, and is subjected to plasma smelting after the raw material is melted. The plasma torch center passes through the protective gas Ar to protect the cathode from oxidation; the ambient O2 gas is used as a reaction material. Oxygen is present in an ion or atomic state in the discharge forming plasma and has a very strong oxidizing property. Stir the molten steel by bottom blowing Ar. The carbon in the molten steel is oxidized in a high temperature oxygen plasma to achieve the purpose of purification. The smelting effect is obvious, and the obtained stainless steel products have w(C) ≤ 4×10-6. The product is used to produce valve bodies with special requirements.
2. Continuous casting tundish plasma heating
Under the conventional process, due to the long continuous casting production process and the large temperature drop of the molten steel, in order to ensure the continuous casting can be carried out normally, it is necessary to have a high degree of tapping superheat, thereby increasing the iron loss and sacrificing the furnace age. At the same time, due to the continuous temperature of the molten steel during the pouring process Changes, it is difficult to ensure the quality of the billet is stable. Continuous casting tundish plasma heating provides the best means of solving the above problems. The use of plasma heating system for tundish steel water heating can achieve near constant temperature casting and reduce the superheat of tapping steel. The benefits are as follows: 1. Low superheat casting increases the pouring speed and thus improves the pouring efficiency; 2. Approximate constant temperature Pouring greatly improves the quality of the billet and reduces the formation of segregation and columnar crystals. 3. Reduces the superheat of the tapping steel, reduces the iron loss, increases the furnace age, reduces the cost and improves the productivity. 4. Reduces the residual amount of tundish steel and reduces the low temperature reflow rate; Reduce the gamble of the mouth. The self-developed 1000 kW continuous casting tundish plasma heating system was successfully used in 1994 for the heating of tundish steel in a continuous casting machine of Maanshan Iron and Steel Co., Ltd.
High-strength high heat-resistant steel plasma melting
In 2003, the self-developed 500 kW high-strength, high-heat-resistant, high-Ni alloy steel plasma melting system was put into production in a Shanghai company. The production process is as follows: (1) The raw material is melted and smelted for 4 h with a 2 t intermediate frequency furnace, and the alloy ratio is sampled and adjusted; (2) the molten steel is poured into a hot ladle and hoisted to a vertical continuous casting production station. The smelting is continued for 20 min with Ar arc plasma. In the process, special alloy material or slag is added. The high temperature plasma melts the slag on the surface of the molten steel, and then the bottom temperature is mixed to make the molten steel temperature and the alloy material composition uniform. The material obtained by this special smelting method has high strength and high heat resistance. The products have been used in China's largest water conservancy project dam ship lock rails, large ship propellers, turbine engine impeller blades and so on.
Forging is a processing method that uses a forging machine to apply pressure to a metal blank to plastically deform it to obtain a forging with certain mechanical properties, certain shape and size. One of the two major components of forging (forging and stamping)
Forging Parts,Steel Structure Part,Die Hot Forged Part,Cnc Machined Part
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