As early as the "National Technology Innovation Project Trading Fair" held in Beijing in 1999, Guizhou's latest practical invention patent, the new technology of ductile iron crankshaft casting, has been developed. According to the data, the main technology of the crankshaft casting industry for gasoline and diesel engines, which is mainly used in the automotive field, is that the foundry raw materials are not limited to high-quality pig iron, which has broad application prospects. Calculated by the annual production of 300,000 tons of automobile gasoline engine and diesel engine crankshaft , it can save 75,000 tons of pig iron, 1650 tons of ferromanganese, 1650 tons of rare earth alloy, 15,000 tons of tar and 7.5 million kW·h of electricity.
Ductile iron has good energy saving and machinability, can obtain ideal structural shape, and can perform various heat treatment and surface strengthening treatments like steel crankshaft to improve the fatigue strength, hardness and wear resistance of the crankshaft . Only about 1/3 of the cost of quenched and tempered steel crankshafts . In theory, ductile iron crankshafts can meet the needs of more powerful engines. For example, as early as 2007, Shandong University published a paper entitled "Getting the Latest WD615 Ductile Iron Crankshaft Development" by Sun Jun. The article points out that the WD615 series diesel engine is a heavy-duty diesel engine that is very mature, widely used and has the largest market in the country. The crankshaft of the engine is processed by die-forging of alloy steel, which has high manufacturing cost, complicated processing and cost of parts. And the price is high, and the use of ductile iron casting and heat treatment process, the shape of the key part of the crankshaft is optimized, the surface treatment of the crankshaft by gas nitriding, plus the world's most advanced rounding force rolling Rolling reinforcement of all journal fillets enables the fatigue strength and service life of the WD615 crankshaft produced by ductile iron casting to meet the requirements of the WD615 series engine and greatly reduce production costs.
Although the iron shaft has these advantages, from the attitude of the OEM, no one is willing to take this risk because it requires a lot of verification and there may be too many risks in the verification process. The facts show that for years, Weichai has always used forged steel crankshafts instead of iron shafts. At the same time, China National Heavy Duty Truck, Yuchai, Xichai, Shangchai, Cummins and other mainstream diesel engine manufacturers have never used iron shafts on high-power models, which has led to the development of these successful technologies mainly in the laboratory stage, or Sold in the crankshaft accessories market.
Experts in the industry believe that: With the development of trucks to high-power heavy-duty trucks, the car is moving toward high-speed and light-weight, and the performance requirements of the engine are getting higher and higher. The cast crankshaft has to face severe tests. Since the crankshaft is mostly damaged by bending fatigue, the greatest advantage of the forged steel crankshaft is that the steel has a high bending fatigue strength and is substantially proportional to the tensile strength. However, the spheroidal graphite cast iron crankshaft has low fatigue strength due to the grain boundary segregation of graphite pores, phosphides and alloying elements, and is not proportional to the tensile strength. With the requirement of high power, low fuel consumption and low emission, the explosion pressure of the engine rises from 8 to 9 MPa to 12 MPa or even 14 MPa, and the ductile iron crankshaft is difficult to bear.
From the change of the use of the crankshaft , in the initial stage of upgrading the diesel engine emission standard, in the face of changes in the requirements of the diesel engine plant, the iron shaft has appeared various kinds of incompatibility, which makes the diesel engine manufacturers express concern about whether the performance of the ductile iron crankshaft can meet the requirements, and also makes them in the crankshaft. At the beginning of procurement, there was a focus on the transfer of forged steel crankshafts . For example, from 2003 to 2008, the crankshaft shipments of the one-forging and forging factory in the Xichai market increased from 30,000 to 100,000 pieces. The growth momentum was strong and it quickly fell back after 2009. In 2012, I returned to the level of shipments 10 years ago. A large-scale reduction in the Xichai crankshaft , a very important reason is the replacement of the Xichai iron shaft. In order to reduce the cost of diesel engines, Xichai has also learned from other diesel engine manufacturers to promote iron shafts.
From the perspective of the crankshaft of the light-duty vehicle engine, after the technical breakthrough, the ductile iron rolling crankshaft applied to the Xichai light-duty vehicle can meet the national III emission standard. Xichai named the traditional 4100 and 4102 engine series “Fuweiâ€, named the traditional 485 and 490 series “Conwayâ€, directly applied the supercharging technology to the light engine, and adopted electronic control technology to realize the diesel engine. Compared with the traditional injection system, the optimal control of diesel injection quantity, injection timing and injection law has greatly improved the performance of diesel engine in low speed zone and large load, and met the national III emission regulations. In 2006, there were 10,000 units installed, 40,000 units in 2007, and 100,000 units in 2008. In 2009, it reached 210,000 units, and more than 30 units including Beiqi Foton, Jianghuai Automobile, Shandong Kaima, FAW Haguang, Shenyang Jinbei and Shandong Shifeng. The well-known light car factory has successfully matched. However, from the recent market reaction, in the case of smog weather for a long time and the country's accelerated emission upgrade standards, various inaccuracies in the upgrade of national IV and national V standards have enabled related companies to achieve new iron shafts. The standard expressed concern and began to try again to re-use forged steel crankshafts to solve new problems that may arise, which pose new challenges for iron shaft manufacturers.
Ductile iron has good energy saving and machinability, can obtain ideal structural shape, and can perform various heat treatment and surface strengthening treatments like steel crankshaft to improve the fatigue strength, hardness and wear resistance of the crankshaft . Only about 1/3 of the cost of quenched and tempered steel crankshafts . In theory, ductile iron crankshafts can meet the needs of more powerful engines. For example, as early as 2007, Shandong University published a paper entitled "Getting the Latest WD615 Ductile Iron Crankshaft Development" by Sun Jun. The article points out that the WD615 series diesel engine is a heavy-duty diesel engine that is very mature, widely used and has the largest market in the country. The crankshaft of the engine is processed by die-forging of alloy steel, which has high manufacturing cost, complicated processing and cost of parts. And the price is high, and the use of ductile iron casting and heat treatment process, the shape of the key part of the crankshaft is optimized, the surface treatment of the crankshaft by gas nitriding, plus the world's most advanced rounding force rolling Rolling reinforcement of all journal fillets enables the fatigue strength and service life of the WD615 crankshaft produced by ductile iron casting to meet the requirements of the WD615 series engine and greatly reduce production costs.
Although the iron shaft has these advantages, from the attitude of the OEM, no one is willing to take this risk because it requires a lot of verification and there may be too many risks in the verification process. The facts show that for years, Weichai has always used forged steel crankshafts instead of iron shafts. At the same time, China National Heavy Duty Truck, Yuchai, Xichai, Shangchai, Cummins and other mainstream diesel engine manufacturers have never used iron shafts on high-power models, which has led to the development of these successful technologies mainly in the laboratory stage, or Sold in the crankshaft accessories market.
Experts in the industry believe that: With the development of trucks to high-power heavy-duty trucks, the car is moving toward high-speed and light-weight, and the performance requirements of the engine are getting higher and higher. The cast crankshaft has to face severe tests. Since the crankshaft is mostly damaged by bending fatigue, the greatest advantage of the forged steel crankshaft is that the steel has a high bending fatigue strength and is substantially proportional to the tensile strength. However, the spheroidal graphite cast iron crankshaft has low fatigue strength due to the grain boundary segregation of graphite pores, phosphides and alloying elements, and is not proportional to the tensile strength. With the requirement of high power, low fuel consumption and low emission, the explosion pressure of the engine rises from 8 to 9 MPa to 12 MPa or even 14 MPa, and the ductile iron crankshaft is difficult to bear.
From the change of the use of the crankshaft , in the initial stage of upgrading the diesel engine emission standard, in the face of changes in the requirements of the diesel engine plant, the iron shaft has appeared various kinds of incompatibility, which makes the diesel engine manufacturers express concern about whether the performance of the ductile iron crankshaft can meet the requirements, and also makes them in the crankshaft. At the beginning of procurement, there was a focus on the transfer of forged steel crankshafts . For example, from 2003 to 2008, the crankshaft shipments of the one-forging and forging factory in the Xichai market increased from 30,000 to 100,000 pieces. The growth momentum was strong and it quickly fell back after 2009. In 2012, I returned to the level of shipments 10 years ago. A large-scale reduction in the Xichai crankshaft , a very important reason is the replacement of the Xichai iron shaft. In order to reduce the cost of diesel engines, Xichai has also learned from other diesel engine manufacturers to promote iron shafts.
From the perspective of the crankshaft of the light-duty vehicle engine, after the technical breakthrough, the ductile iron rolling crankshaft applied to the Xichai light-duty vehicle can meet the national III emission standard. Xichai named the traditional 4100 and 4102 engine series “Fuweiâ€, named the traditional 485 and 490 series “Conwayâ€, directly applied the supercharging technology to the light engine, and adopted electronic control technology to realize the diesel engine. Compared with the traditional injection system, the optimal control of diesel injection quantity, injection timing and injection law has greatly improved the performance of diesel engine in low speed zone and large load, and met the national III emission regulations. In 2006, there were 10,000 units installed, 40,000 units in 2007, and 100,000 units in 2008. In 2009, it reached 210,000 units, and more than 30 units including Beiqi Foton, Jianghuai Automobile, Shandong Kaima, FAW Haguang, Shenyang Jinbei and Shandong Shifeng. The well-known light car factory has successfully matched. However, from the recent market reaction, in the case of smog weather for a long time and the country's accelerated emission upgrade standards, various inaccuracies in the upgrade of national IV and national V standards have enabled related companies to achieve new iron shafts. The standard expressed concern and began to try again to re-use forged steel crankshafts to solve new problems that may arise, which pose new challenges for iron shaft manufacturers.
Bridge Faucets,bridge kitchen faucet,Bridge Faucets price
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.kitchen-sinkfaucets.com