Methods Of Improving Tolerance Of Forgings
Methods of Improving Tolerance of Forgings
Forgings is widely used in machinery, energy, compressors, offshore oil machinery and other fields. Forgings shape is complex, wall thickness changes in size, its radiographic detection, usually need to test the area of repeated exposure, need to be improved, that is, to improve the radiographic tolerance, the main measures are:
1. Forgings the area of the area
Forgings geometries are complex and the cross-sectional size changes greatly. The radiographic detection is based on the tolerance of the transparent area, which can optimize the process parameters and reduce the number of passes. That is: to meet the radiation field and a pass through the length of the conditions as much as possible to do the normalization; the same thickness of the region is divided into the same film for a pass; for the thickness of the region, the use of film tolerance and more Film technology to maximize the length of a pass through to reduce the number of pass; for the thickness of the symmetrical area, the use of symmetry of the exposure of multiple films at a time.
2. Application of ray source characteristics
Commonly used ray sources are mainly χ-ray machine, γ source and accelerator, the application of the thickness and the use of different advantages. The χ-ray machine is mainly used for the penetration of the thin-walled area of the Forgings, and the transparency is better than that of the γ-ray. The γ source is more suitable for the penetration test of some complex cavity Forgingss and can be exposed in the circumferential direction. The main features of the accelerator are energy , Penetrating power, short transit time, high efficiency, wide photographic thickness tolerance.
3. Using multi-chip technology
Multi-film technology is in the dark bag at the same time into two or more photosensitive speed of the same or different film for transmission, there is a good degree of consistency of blackness. When the film is placed in different thickness of the film to be photographed, through the thickness of the site with a high speed of the film to observe the assessment, through the thickness of the small parts of the film with low sensitivity to observe the film; Bag into the same speed of the two film to be photographed, the thickness of the location of the two films can be superimposed on the observation and evaluation, the thickness of the small parts with a single observation.
4. Thickness compensation and shielding
Many of the Forgings shape complex, through the thickness difference, the use of high-energy X-ray accelerator through the pass can often meet the ability to pass, but also increased the film fog, there will be "edge erosion" phenomenon; according to the specific parts of the production Of the compensation block and make the necessary shielding measures, can reduce the negative black film and "edge erosion" effect, increase the film tolerance, improve the film clarity.
Downstream industry Forgings demand structure changes significantly. From the industry demand for Forgingss, car Forgings accounted for a quarter of the car production and structural changes on the total amount of Forgingss changes are very large; all kinds of pipe fittings accounted for 12.2%.
Although China is already a veritable Forgings power, but China's Forgings product quality and the international advanced level there is a clear gap. Most of the product quality indicators there is a stage gap, imitation of the more innovative less. Some product quality standards itself there is a clear gap. The whole process of control poor, good time difference, the lack of quality and stability.
Product sales sluggish to promote part of the Chinese Forgings enterprises played a price war, a ripple, and soon the price war in China's low-end Forgings production areas of rapid spread, so that the whole of China's low-end Forgings products market smoke filled.
In the case of double growth of raw materials and labor costs, the Chinese Forgings industry, there is no excess profit margins for price promotions, not to mention the product value is very low low-end Forgings production enterprises. To promote the low-end Forgings manufacturers have repeatedly cut prices because of low-end Forgings overcapacity, product homogenization of the phenomenon is serious. The above two factors led to China's low-end Forgings production enterprises a large number of backlog Forgings products, in order to reduce inventory pressure, beat opponents, low-end Forgings production enterprises played a price war, or even lower than the cost price to carry out vicious competition.
Forgings enterprises such as poisoning thirst-style competition is not only disturb the normal China's Forgings market order, but also accelerated its own rate of demise.