Abstract : According to the specific requirements for the quality evaluation of modern castings, the detailed projects of modern casting detection and control technology are proposed for the first time and classified, and the specific implementation ideas of modernization of automobile casting inspection technology in China are proposed.

Keywords : automotive castings; inspection and control technology; modernization

1. The Challenge of China's Automobile Foundry Testing Technology in the Early 21st Century

From the point of view of modern casting at the end of the 20th century, the evaluation of casting quality has given a new concept. The quality of castings should be considered from three aspects: product quality, process quality and casting design quality. The main contents are as follows.

(1) Product quality

The quality of the cast product includes surface quality, intrinsic quality and quality of use. The surface quality mainly includes: dimensional accuracy, shape tolerance, surface roughness, surface hardness, weight tolerance, lumen cleanliness and surface casting defects. The intrinsic quality mainly includes: chemical composition, metallographic structure, metallurgical defects, physical and mechanical properties, reliability inside the casting (inspected by non-destructive testing), and in recent years, grain size (number of eutectic groups), eutectic saturation, Density, purity, continuity, etc. The quality of use mainly includes: cutting performance, welding performance, running performance, wear resistance, corrosion resistance, temperature resistance, working life and other working conditions, and its indicators are also constantly improving.

(2) Process quality

It is the basis for the quality of casting products, from raw materials, production processes to semi-finished products (such as molten iron, molding sand) to the quality of the finished casting process.

(3) Quality of casting design

In recent years, more and more attention has been paid to the quality of casting design. This is because many casting defects are bred during the design process, that is, poor casting design will reduce the quality of the production process and product quality.

Recalling that the automobile foundry industry since the founding of the People's Republic of China is the same as the foundry enterprises in the country, compared with the advanced level of foreign casting. The biggest problem in China's current foundry industry is low product quality, poor economic returns, high material consumption, and large environmental hazards. In order to promote product quality and economic benefits, in the future, China's foundry industry must urgently improve the management level of enterprises, implement the IS09000 standard management, expand and improve the casting standards, solve the poor quality of raw materials and continuously improve the level of technology and equipment. Constantly supplement, improve and improve the quality inspection and quality control methods of the casting process. Because the improvement of the material, process and equipment level and quality management level of the casting depends to a large extent on whether the detection and control methods of the whole casting process can be matched and can be kept up, that is, everything needs to be said with data, everything must be With metering management, everything needs to be controlled by quality and cost. However, reviewing the development of inspection and control technology for automobile foundries since the founding of the People's Republic of China, as well as the national foundry companies, compared with modern foreign castings, if the level of casting technology, equipment and management is still relatively backward, then the quality of the foundry Detection and quality control techniques are even more backward. Although there are quite a few objective factors in the cause of this situation, there are still many enterprises that lack sufficient understanding of the key role, great power and economic benefits of casting quality inspection and control.


In particular, the rapid development of microelectronics technology, especially computer automatic control technology, has brought unprecedented opportunities and broad prospects to the multi-factor and multi-variable complex casting detection and control problems. The detection and control equipment of the casting process uses microelectronic technology, which has become one of the important trends in the development of casting equipment and instruments in recent years. From the recent casting fairs that best represent the world's advanced level of casting, it can be seen that the latest casting technology, equipment and equipment are combined with the latest microelectronics, computer automatic detection and control technology. The practice of modern foreign casting has shown that this advanced detection and control technology can be applied to casting production as quickly and effectively, not only can significantly improve and stabilize the quality of castings, but also effectively improve labor productivity and improve working conditions. , to reduce energy consumption, material consumption, reduce the functional weight, functional cost and final cost of castings (including saving processing costs, etc.), thus bringing huge economic benefits to foundry enterprises. In terms of the above technologies, although China has begun to carry out work in this area and has achieved some initial results, it is still at a stage of slow development at a low level, which is far from the advanced level of foreign countries. .
In summary, the development of modern casting at the end of the 20th century has put forward higher requirements for us. If our automobile foundry enterprises do not pay much attention to and vigorously supplement and develop casting quality inspection, control and measurement techniques, they will not be able to adapt to the quality of modern castings. Evaluating standards and the growing demand for modern automotive castings, and will inevitably widen the gap between the materials, processes, equipment and management levels of our automotive castings, and even the “fuzzy casting production” based on the sensory experience of the naked eye. The history can not reverse the long-term loss of the foundry, and will become a bottleneck restricting the automobile foundry's quality, quality, market, product expansion, cost reduction and efficiency.

2. Modern casting quality inspection control technology classification model

In order to make the casting production gradually free from the shackles of experience and skill, and to comprehensively improve the quality control level of each link in production, it is necessary to continuously supplement, improve and improve the quality testing and testing techniques of the casting process. The advanced casting quality inspection technology and means are the ear and eye of casting production, and also the ear and eye of casting quality control. The fact that domestic experience in producing high-quality castings in recent years and the successful introduction of advanced foreign technology have shown that it is impossible to organize modern casting production without advanced casting inspection technology. In the following, the author attempts to give a classification model to the quality inspection and control technology generally used by modern foreign foundry companies according to the casting process.

2.1 Quality inspection of raw materials for foundry

Raw material quality testing refers to the detection or re-inspection of chemical composition analysis and physical property testing of various casting materials including pig iron, scrap steel, iron alloy, molding sand, coke, binder, coating, catalyst, etc. In order to strictly control the quality of raw materials.

2.2 Detection of molten iron quality before furnace

(1) Detection of the tapping temperature and pouring temperature of the molten iron before the furnace;

(2) High-speed automatic detection of the content of related elements in the pre-furnace molten iron and various treated irons; (direct reading spectroscopy, etc.)

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