China's foundry industry is in a critical period from a big producer to a strong foundry. The upgrading of products, the upgrading and transformation of product structure is a challenge to every foundry. In the casting production technology discussion special report of four enterprises gave us a lot of important enlightenment. As any casting, there are always technical requirements and quality standards, the quality of its quality will affect the quality, safety and life of the machine. From this point of view, there is no high or low end casting. However, with the rapid development of China's economy, the high performance, high efficiency, high reliability of all kinds of mechanical and electrical equipment and devices in various economic fields are increasingly demanding the quality of castings. Therefore, casting enterprises are required to cast high-quality, high-performance and high-level castings to meet the needs of various industrial fields. These castings are often called "high-end" castings. It is concluded that high-end castings have three characteristics.
1. The equipment carried by this kind of casting has an important position in the national economy, and the quality of this kind of casting has a decisive influence on the safety, quality and life of its components. That is, the role of the casting is significant, and the enterprise responsible for producing this kind of casting is significant. Take the castings produced by four enterprises on the forum as an example: for example, the bogie axle box on the high-speed train that implements "zero tolerance" for quality problems; The wind turbine is required to use wind turbine castings that have not been replaced for 20 years; Machine tool castings with high carbon equivalent, high strength, high stiffness and low stress of precision CNC machine tools; Automobile support with high fatigue strength requirements of QT800-5 material.
2, high-end casting has high performance requirements and greater manufacturing difficulty. Its production enterprises at any time to put the quality of production and quality in place, quality concept and requirements to carry out the production of products from beginning to end. Some domestic enterprises have insufficient understanding of the technical difficulty and management difficulty of producing high-end castings, just because of the higher price. Not from improve the technical level and management level of effort, but "short cut", with low price to earn the order first, then with low-cost manufacturing and the low level of management to produce high quality requirements of high-end castings, and appeared to many quality problem had to give up, even to make our country high-end castings production was given a severe interference, roiled markets.
Wind turbine castings, machine tool castings and automobile castings have similar situations in the previous period. As a result, the production enterprises of high-quality castings have invested a lot of quality costs, but the low price orders make it unprofitable, which also makes the users at home and abroad question the ability of China to produce high-end castings, and also causes the wrong judgment of the price positioning of high-end castings. Practice shows that the production of high-end castings is not an easy thing, in the management concept, in the production process of technical control, in the strict quality management of enterprises are required to have a qualitative improvement. This is a difficult and unavoidable transition.
In terms of concept, it is important to put quality in the first place and reduce costs on the premise of ensuring quality. Responsibility and credibility are important in producing high-end castings. For the QT400-18Al axle box at -40℃, the surface defect inspection rate is 10%, and the Ward considers that the surface defects directly affect the safety and stability of the axle box, it is changed to 100% inspection. In the bidding process, Ward is often subjected to cut-price competition, but after repeated consideration, it is preferred to sacrifice profits and insist on using high-priced pig iron and high-quality carbon steel to ensure the implementation of the quality assurance system for raw material procurement.
Enterprises producing high-end castings, if they do not put quality first, it is fatal to the survival of the enterprise, and the negative effect on the society is bad. On the contrary, it can produce high-quality high-end castings, which is a promotion and guarantee for high-end electromechanical products in various fields of the national economy.
3, the characteristics of high-end casting is the high level of performance and high stability of quality, both are indispensable.
Some domestic enterprises attach great importance to the development, the high level of trial products and the quality concept of production after the lax and quality fluctuations are often many enterprises to produce high-end casting defects, the production of high-end casting has two characteristics: one is its high quality, high performance requirements; Second, the high stability of casting quality in production; High quality and high performance requirements of high-end castings;