On June 2, 2016, the Ford Ecotorq heavy-duty diesel engine produced by China's leading heavy-duty truck Co., Ltd. officially rolled off the assembly line at the Taiyuan engine production base.
Ford's Ecotorq heavy-duty diesel engine adopts a series of world-leading technologies with excellent performance in various indicators. Among them, a vermicular graphite cast iron technology is outstanding.
The commissioning of the 9L/13L vermicular graphite cast iron engine puts an end to the situation that China's heavy-duty truck engine has not stabilized the production of vermicular graphite cast iron, and fills a technical gap in the application of metal materials for China's heavy-duty truck engine. SXJL's engine vermicular iron cylinder technology also won the gold medal, the highest honor in the foundry industry, at the 14th China International Foundry Expo.
Advantages of Vermicular Graphite Cast Iron Technology
For the cylinder block and head material of heavy-duty engines, gray iron cast iron is traditionally used. The technology of gray iron material is very stable and mature, and the cost is relatively low. However, with the advancement of science and technology, people's needs are constantly increasing, and people continue to put forward higher requirements for the fuel economy, power, emission performance, lightweight, and high-horsepower of heavy-duty trucks.
To improve the performance of the engine and reduce emissions at the same time, the main way is to increase the explosion pressure in the cylinder, but increasing the explosion pressure will bring additional thermal load and mechanical load to the engine block. The traditional gray cast iron cylinder block and head material has deficiencies in load resistance, which has become a bottleneck restricting the improvement of engine performance.
In order to further improve engine performance, engineers began to look for high-performance alternative materials, and it was found that vermicular graphite cast iron is the best material for a new generation of high-performance engines. Vermicular graphite cast iron has similar seismic performance, thermal conductivity and casting performance to gray iron cast iron, and far surpasses gray iron cast iron in the following three key properties:
High strength: The tensile strength of vermicular graphite cast iron is more than 75% higher than that of gray iron, and the fatigue strength is almost twice that of ordinary gray iron. With the use of vermicular iron, the explosion pressure of the engine can be significantly increased, thereby improving fuel economy and power performance, and reducing emissions.
High rigidity: The rigidity of vermicular graphite cast iron is 45% higher than that of gray cast iron. The use of vermicular graphite cast iron for the cylinder block and head can reduce the deformation of the cylinder bore, reduce oil consumption, and effectively improve NVH performance.
High wear resistance: Under the same abrasion test, the wear of vermicular graphite cast iron is only 45%-60% of gray cast iron. After the cylinder body is made of vermicular graphite cast iron, the design without liner can be adopted to reduce costs.
Development of Vermicular Graphite Cast Iron Technology
The casting of vermicular graphite cast iron is not easy to realize. To ensure the good quality of the engine, the key parts of the vermicular iron cylinder block and cylinder head must achieve a creeping rate of more than 80%. It is difficult for traditional casting technology to stably obtain such a high creeping rate.
Technical difficulties are often also the driving force for technological progress and development. With the continuous efforts of countless people for decades, the technical bottleneck of vermicular graphite cast iron has gradually been broken. By the 1990s, Sweden's Sintercast company had successfully developed a new type of vermicular iron production technology that could obtain a very stable high creeping rate.
In this century, the use of vermicular iron casting in heavy-duty engines in Europe has become quite common. Among them, manufacturers such as MAN, DAF, Mercedes-Benz, Volvo, Ford, and Caterpillar have applied vermicular iron materials to cylinder blocks and cylinder heads in batches.
Ford has always been an advocate and pioneer of vermicular graphite cast iron technology. At the 2016 North American International Auto Expo (NAIAS) in Detroit, Ford's vermicular graphite cast iron diesel engine cooperating with SinterCast was unveiled in a high profile on Ford's ace model F-150 pickup, 2017 The F150 pickup truck model will be equipped with a 3.6-liter V6 turbocharged diesel engine with a vermicular graphite cast iron block and a 2.7-liter vermicular graphite cast iron EcoBoost gasoline engine. The EcoTorq engine on the Ford Cargo heavy trucks currently sold in Europe and South America is also made of vermicular graphite cast iron.
A breakthrough in vermicular graphite cast iron technology
Compared with the booming foreign countries, the application of vermicular graphite cast iron in China's heavy-duty engines started late. Prior to this, the development of vermicular graphite cast iron engines by major Chinese heavy-duty truck manufacturers was still in the stage of research and trial production, and there were not many large-scale mass productions. .
SXJL took advantage of Ford's technical advantages and introduced high-performance 9L/13L Ecotorq vermicular iron cylinder head heavy-duty engine technology from Ford. In order to overcome the technical problems of cylinder block and cylinder head vermicular iron manufacturing, SXJL introduced the world's most advanced Swedish SinterCast Vermicular graphite cast iron manufacturing technology, digested and absorbed it, and finally formed its own core competitiveness.
After more than two years of hard work, the SXJL scientific research team has successively obtained 1 national invention patent and 2 utility model patents. At present, SXJL has fully mastered the core technology of vermicular iron production and control, and has created SXJL with completely independent intellectual property rights. Vermicular iron control technology by comparison method.
The creeping rate of the vermicular iron cylinder block and head of the heavy truck engine developed by SXJL can stably reach more than 80%, and the key part can even reach 95%. All components have passed the DV test, engine bench and vehicle performance and durability test in accordance with Ford's development process and technical requirements.