The transformation and upgrading of many foundry enterprises is the foundation of China’s transformation from a big foundry country to a powerful foundry country. Among them, the upgrading of product structure is a representative sign of enterprise transformation, transformation and upgrading.
From the perspective of service, safety and service life, there is no high-end or low-end casting. However, with the rapid development of China’s national economy, all kinds of mechanical and electrical equipment and devices with high performance, high efficiency and high reliability appear in various fields, which require the casting enterprises to produce castings with high quality, high performance and high level. These castings are called high-end castings.
The emergence of high-end castings has attracted the attention of many enterprises. The 12th China International Foundry fair, the first China Foundry Festival, also featured “intelligent, green and high-end”, exhibited castings of high quality, high performance and high level that have a significant impact on all kinds of mechanical equipment in various fields of China’s national economy. However, what can the foundry enterprises do to realize the “upgrading of products and upgrading of product structure”? Here, the author only gives the important enlightenment of the four high-end casting production enterprises in the special exchange meeting of cast iron production technology, which is summarized and shared as follows.
The equipment carried by high-end castings plays an important role in the national economy, and the quality of this kind of castings has a decisive influence on the safety, quality and service life of its component equipment, so the enterprise producing this kind of castings has a great responsibility.
1. Bogie Axle Box of high-speed train
Bogie axle box is a type a part of rail transit parts, which is equipped with high-speed wheels rotating at full speed under and carriage carrying hundreds of passengers on the top. Its quality directly affects the safety, stability and comfort of high-speed trains. When the train is running, the axle box bears complex forces. There are not only the impact and vibration of the line to the car body, but also the resistance friction between the wheel and rail and the resistance of the wheel hunting movement. They are concentrated on the axle box of the bogie. Once the part fails, the consequences are unimaginable. In other words, it is not allowed to have one unqualified product for manufacturing 100 pieces, 1000 pieces and 10000 pieces.
The incomparable superiority of high-speed train in modern traffic must be based on the extremely safe foundation. Because the quality of the axle box has a great influence on the safe operation of high-speed train, it is listed as high-end casting. For a long time, the axle box of – 40 ℃ low-temperature nodular cast iron crh380 bogie with material grade qt400-18al has been made in foreign countries, all of which depend on import.
2. Wind Turbine Casting
The “high end” of wind power components is fully reflected in the service life and safety of wind turbine. Wind power equipment requires that the wind power casting must not be replaced for 20 years. In case of accidental failure, it is not only difficult to replace parts at a height of hundreds of meters, but also the cost of replacement is huge, even exceeding the original price. In addition, it is difficult to estimate the loss due to the failure to generate electricity in time. Jiangsu Jixin Wind Energy Technology Co., Ltd. (hereinafter referred to as “Jiangsu Jixin company”) produces large section wind power parts, which not only plays an extremely important role in the wind power equipment, but also plays an important role in the domestic and foreign wind power market.
3. Casting of CNC machine tool
As we all know, high-end CNC machine tools are one of the important symbols of national competitiveness and the engine of national economic development. The manufacturing level of high-end CNC machine tools is the symbol of a country’s comprehensive strength. At present, China’s high-end CNC machine tools still rely on imports, one of the reasons is that there is a large gap in the casting quality of high-end CNC machine tools, among which the poor rigidity of casting materials and high casting stress are the main reasons that affect the accuracy and accuracy retention of machine tools. The production of high-end precision CNC machine tool castings with high rigidity and low stress is the basis of the production of precision CNC machine tools.
It is not difficult to produce machine tool castings that meet the requirements of strength and hardness, but it is more difficult to produce high-end machine tool castings with high CE, high strength, high rigidity and low stress. In order to develop this kind of machine tool casting with high dimensional accuracy and high stability, the state has also assigned a research project. Yantai ice wheel Heavy Machinery Co., Ltd. (hereinafter referred to as “Yantai ice Wheel Co., Ltd.”) “quality control of high-end CNC machine tool castings” report represents the production status of high-end machine tool castings in China.
4. High end ductile iron castings
ZHY casting is a typical representative of transformation and product upgrading of foundry enterprises. For a long time, the company’s main export products are matching and re casting parts. Its casting output has reached the first in the world, known as “king of counterweight”. With the change of market economy, the transformation of this kind of low-end products is urgent. At present, the company has begun to develop and produce high-end ductile iron castings. The ideas and practices of transformation and product upgrading of the enterprise deserve attention.
ZHY casting has gradually shifted from production counterweight to production of four categories of ductile iron castings which play an important role in high-end castings, namely: ADI with high strength and plasticity, qt800-5 with high fatigue strength requirements, high Si ductile iron with excellent processability (qt450-18, qt500-14, qt600-10) and low temperature ductile ductile iron (- qt400-18al at 40 ℃, – 50 ℃). Among them, qt800-5 is of great significance in the application of automobile chassis bracket. The development of a domestic unit shows that: when QT450-10 is used in automobile bracket, its bracket mass is 190 kg; when qt700-3 or QT600-3 is used, its bracket mass is 120 kg; when qt800-5 is used, its bracket mass is 90 kg. Therefore, the application of qt800-5 bracket with high fatigue strength will significantly promote the lightweight of automobile, realize energy saving and emission reduction, and improve the safety and service life.