Good strategy for domestic precision casting products
First, the level of technology is low, the quality of precision casting products is poor 1. The crack problem of castings is serious. 2. Separation of large castings and serious defects in inclusions. After the solidification of large steel castings and large steel ingots, there are problems of macrosegregation and coarse grain in the thick section of the riser and the casting. 3. The application of simulation software is not popular. Casting process simulation is a necessary part of casting production. In foreign countries, if there is no computer simulation technology, orders will not be available. China's foundry computer simulation started earlier. Although the core computing part has strong development capabilities, the overall software packaging capability is poor, resulting in mature commercial software development far behind developed countries. A considerable number of foundry companies are discouraged from computer simulation technology. lack of trust. At present, although this situation has improved, but in the enterprises that have purchased casting simulation software, it is still rare to play its role, and it is urgent to train software applications for employees. 4. Excessive production capacity of ordinary castings, manufacturing of high-precision castings is still difficult, and core technologies and key products still rely on imports. 5. The precision casting processing has a large margin. Due to the lack of scientific design guidance, it is difficult for process designers to control the deformation problem based on experience. The machining allowance for casting is generally 1-3 times larger than that of foreign countries. The processing allowance is large, the energy consumption of the castings and the consumption of raw materials are serious, the processing cycle is long, and the production efficiency is low, which has become a bottleneck restricting the development of the industry. 6. The design of the gating system is unreasonable. Due to improper design, there are defects such as gas and inclusions, resulting in low casting yield and yield.
Second, the environmental pollution is serious, the operating environment is bad. In addition to a few large enterprises such as FAW, Second Automobile, Daqi Dazhong, Shenyang Liming Company and other production equipment, advanced precision casting technology, environmental protection measures are basically in place, most foundry production equipment Obsolete, backward technology, and rarely take into account environmental issues. In the 1980s, the government made special adjustments to enterprises with small scale, low technical level and serious pollution, which increased the degree of intensification of enterprises, but the extensive characteristics of foundry production have not been fundamentally changed. The environmental problems in China's foundry industry are also reflected in the excessive consumption of natural resources.
Third, high energy consumption and raw material consumption China's precision casting industry energy consumption accounts for 25%-30% of the total energy consumption of the machinery industry, the average energy utilization rate is 17%, energy consumption is about twice that of foundry developed countries. The energy consumption per ton of qualified cast iron produced in China is 550-700 kg of standard coal, and that of foreign countries is 300-400 kg of standard coal. The energy consumption per ton of qualified steel castings produced in China is 800-1000 kg of standard coal. 500-800 kg of standard coal. According to statistics, the input of materials and energy in the production process of castings accounts for 55%-70% of the output value. The gross weight of Chinese castings is 10%-20% higher than that of foreign countries. The average yield of steel castings is 55%, and that of foreign countries is 70%. In the casting production, the charge is mainly pig iron, scrap steel, coke, limestone, sand, core sand. Mainly used for transportation, sand mixing, molding, core making, baking, melting, pouring, cooling, falling sand, cleaning and post-treatment of raw sand, clay, coal powder, resin and other binders, curing agents, old sand, etc. The process is carried out in terms of mechanical vibration and noise, and some work in high-temperature melting and pouring, and some produce irritating odors, and the dust working environment is even worse. These above illustrate the severity of environmental problems in China's precision casting industry. The use of high technology to achieve green casting is a key issue that needs to be addressed at present.