Europe is the global research center for diesel engine technology and has witnessed the transformation of compacted graphite iron (CGI), which has become a recognized raw material for cylinder block manufacturing, replacing the commonly used gray cast iron. This material is stronger and harder than traditional gray iron, and was originally used in passenger car production by large automobile manufacturers. However, now large European car manufacturers have adopted this advanced cylinder block material.
Vermicular graphite cast iron has two major advantages: its strength means that engineers can start the engine at higher cylinder pressures to meet increasingly stringent exhaust emission requirements; if the pressure increases moderately, designers can reduce the weight of the engine and improve its compactness sex.
The improved properties of vermicular graphite cast iron will replace gray iron in the same application. In this case, it can improve durability and extend the service life of the engine. Under particularly harsh operating conditions, repeated experiments are carried out on the harsh cylinder block and cylinder head: the improved vermicular graphite cast iron can prolong their service life and reduce maintenance costs.
In 2004, sales of diesel vehicles in Europe accounted for 48.5% of the total number of newly registered vehicles, compared with 43.8% in 2003. In this industry, subtle changes are gradually taking place. Due to the use of vermicular graphite cast iron cylinder blocks, Audi Motor Company and Ford Motor Company have developed more powerful diesel engines to provide better performance.
Audi Motor Company began using vermicular graphite cast iron in the production of 3.3-liter V8TDI engines in 1999. Since then, Audi has developed 2.7-liter and 3-liter v6 diesel engines for use in its A4, A6 and A8 models.
Ford's 60-degree V6 2.7-liter Lion diesel engine has 155kw of power and 440Nm of torque. Equipped with a twin-turbocharged engine for the Jaguar S sedan and the latest off-road Land Rover sports utility vehicle. In cooperation with PSA Peugeot Citroen Group, Lion engines have been further developed.
The engine will play an important role in the bidding of Ford products to stay at the forefront of emissions regulations. In the United States, the twin-turbo engine has been used in a new concept vehicle-the Ford Mercury Meta One concept car. Mazda Motor Company, in which Ford has a stake, has just produced a new type of "CrossPort" sports utility vehicle, which is also used V6 Lion engine with vermicular graphite cast iron as the cylinder block. A 90-degree v8 engine will also be used in off-road Land Rover and Range Rover sports utility vehicles, and may be used in Ford's light trucks in the United States.
The V6 Lion engine is machined and assembled at Ford's Diesel Engine R&D Center in Dagenham, UK. The center also assembles v8 engines. Dagenham also plans to produce 400,000 other small compacted graphite iron diesel engines every year.
However, what makes vermicular graphite cast iron the most attractive raw material, and what makes it difficult to produce on a large scale? Ford claims that it will take eight years to develop its production system in order to cope with the increased strength and rigidity, while the British factory has to introduce new production technology and machine tools.
The production of compacted graphite cast iron requires 25 grams of magnesium per ton of molten iron, the quantity must be accurate, and the error range cannot exceed 0.004% of the magnesium content. Therefore, the foundry industry has to use professional computer process control technology to obtain suitable products.
Many foundries closely related to the automobile industry have developed their own technology for producing vermicular graphite cast iron, but the most widely used process control technology was developed by SinterCast in Sweden. The company has reached agreements with many foundries around the world, including Tupy in Brazil. This plant is also the production location of Ford and Audi's v6 cylinder blocks.
Tupy is the largest foundry in South America, with an annual output of 440,000 tons. More than 60% of Tupy's sales are exported to its contracted customers, including Cummins, General Motors, Ford, PSA, DaimlerChrysler, Volkswagen, Iveco, Komatsu and Kubota. The company also cooperated with Toyota Motor Corporation to produce a lightweight vermicular graphite cast iron cylinder block for gasoline racing engines.
However, it is not just the advantages of vermicular graphite cast iron that automakers can take advantage of. European truck manufacturers pay close attention to the development of this technology and invest in it.
It has 75% higher elongation strength than ordinary gray iron, 40% higher modulus of elasticity and nearly twice the fatigue strength. From this, it is easy to see why European truck manufacturers have recognized the opportunity of vermicular graphite cast iron. . Their engine designers can improve performance and reduce exhaust emissions while reducing the size and weight of the engine. Dafu, Auman, Daimler-Chrysler, Iveco and Scania Trucks all use vermicular graphite cast iron casting technology to improve engine product performance.
New trucks using vermicular graphite cast iron engines include Dafu and Paka MX series. With a displacement of 12.9 liters, the engine can be improved to a power between 305 and 418kw and a torque between 2000 and 275ONm. A prototype of a 38OkW engine has been developed, providing 25000Nm of torque. It will go on sale in the fall of 2005. When Auman wanted to reduce the weight of its new engine by 100 kg, it chose to use high-strength GJV-450 variable vermicular graphite cast iron as the crankcase.
Daimler-Chrysler's Mercedes-Benz Truck Division also chose vermicular graphite cast iron to produce the new v8 automotive engine. Mercedes-Benz engineers claimed that due to the use of vermicular graphite cast iron, the engine achieved a higher power density and became quieter. If further evidence is needed, the company will carefully select materials. Mercedes has also developed its own vermicular graphite cast iron process control technology.
At present, vermicular graphite cast iron is still mainly used in V-structure diesel engines. In order to obtain raw materials, processing efficiency and economies of scale, manufacturers further invest in product technology. Vermicular graphite cast iron will be a viable option for controlling low-priced internal combustion engines. As long as this is achieved, the use of vermicular graphite cast iron for gasoline engines will no longer be far away.