When some domestic foundry enterprises change from the original production of low-end products to the production of high-end castings with extremely strict quality requirements, they are often impatient and always want to find the “know-how” overnight, which usually leads to failure. A large number of practices have proved that in order to produce castings with high quality and stability, efforts must be made on the basis of common basic technologies, such as high-quality smelting, high-quality primary molten iron, high-quality furnace pretreatment and strict control of each process.
Meticulous management, meticulous operation and strict process control are the guarantee of high-end casting quality stability. ZHY casting strengthens the quality concept and reaches the consensus that high quality and high stability are the important marks of high-end casting production. It is composed of leaders, technical personnel, purchasing personnel, management personnel and operation team leaders. The scheme and measures are connected to the end without discount. Put the product quality first, and operate carefully; manage from raw materials, each process has standards and operation points; product quality should go through a series of tests; control smelting parameters, chemical composition content, metallographic structure, performance index, etc. in a narrow range; performance test should not only have single cast sample, attached cast sample, but also body sample; The quality of castings should not only be qualified, but also be very stable.
It is because of a lot of solid work in quality management and basic technology that a good result has been achieved in the development and production of high-endcastings.
It is a detailed and solid work to improve the common basic technology of foundry enterprises, which is fully illustrated by the journey of ZHY casting in the molten iron temperature. It is pointed out in the report that it has been a long and painful process for us to know the furnace outlet temperature, and then we have gradually determined a more reasonable temperature range. In recent years, the change of furnace temperature and scrap rate.
After the performance of high-end castings reaches the standard, the management level and ability are the decisive factors for the high stability and consistency of product quality. According to the person in charge of ZHY casting, castings that use more complex technical means or have one or several technical requirements that are difficult to meet can be called high-end castings. There are many enterprises with the ability to produce qualified samples, but to guarantee the quality of products over the years is another matter. After the success of high-end casting test, management level is the decisive factor. The success of the test can only show that the correct method has been adopted and the ability to reach the goal can not be guaranteed to be achieved every time. At this time, only serious management can guarantee the stability of production and the consistency of product quality. Among them, people are the most important factor. Only when people’s ideas are right can people’s attitudes be changed, people’s actions be kept up, people’s abilities be improved, and the high consistency of product quality is inevitable.
High level of technology and high stability of quality are two conditions that high-end castings must have at the same time. The instability of quality is the biggest problem of foundry enterprises in China, which is mainly caused by the lack of strict management. According to the person in charge of ZHY casting, the successful development of high-end castings can only show that there are technologies and means to reach the performance index, but the technology can not guarantee that the quality of each furnace and each piece can reach the qualification. In the production process, in order to improve the management level, ZHY casting specially carried out ISO 9000 certification; after the rail products were put into production, TUV of Germany was invited again for iris audit. In order to achieve the purpose of strict management, the audit of CRCC, German railway transportation and French railway transportation departments was also carried out. During this period, all the management personnel meticulously carried out the rectification according to the specified requirements, such as: in order to ensure the quality of high-purity pig iron, a separate high-purity pig iron special warehouse was established, and the unqualified pig iron could not be put into storage or leave the factory, The main components of pig iron shall be rechecked after arriving at the plant, and the unqualified iron shall not enter the workshop; the spheroidizing treatment time shall be strictly controlled within 60-90 s, and the pouring time shall not exceed 300 s; 4000 furnace times shall be counted, without any violation; to ensure the quality, six axle boxes shall be poured in each furnace, hanging on the same bracket, so as to facilitate the quality tracing.
(1) At present, China is in a critical period from a big foundry country to a powerful foundry country, and the realization of the dream of a powerful foundry country needs the support of many strong enterprises, so the transformation and upgrading of foundry enterprises and product upgrading are important tasks in this period.
(2) High requirements of casting properties and high stability of casting quality are two necessary conditions for high-end castings.
(3) In order to produce castings with high quality, high performance and high level, it is necessary to do a good job in basic technical work and strictly carry out process control, and quality concept and management ability are the decisive factors of quality stability.