Methods for quality inspection of aluminum alloy forgings
1. The sulfur printing method is mainly used to check whether the sulfur distribution is uniform and whether the sulfur content is high.
2. Except that the low magnification test samples of structural steel and stainless steel forgings are not subject to terminal heat treatment, forgings of other materials are generally subject to low magnification test after terminal heat treatment;
3. Fracture samples usually undergo specified heat treatment. The principle of microstructure inspection is to use optical microscope to inspect the microstructure of forgings of different materials. The inspection items generally include the basic grain size or the grain size at the specified temperature, that is, the microstructure required for the actual grain size, non-metallic inclusions, decarburized layer, eutectic carbide inhomogeneity, overheating, overheating structure, etc;
4. Mechanical and technological performance inspection is to process the specified final heat-treated forgings and test pieces into specified samples, and then use tensile testing machine, impact testing machine, durability testing machine, fatigue testing machine, hardness tester and other instruments to determine the quantity of mechanical and technological properties;
5. Chemical composition test generally adopts chemical analysis or spectral analysis to analyze and test the composition of forgings. With the development of science and technology, chemical analysis and spectral analysis have made great progress. For spectral analysis, spectral analysis and spectral analysis are not only used for component analysis. The emerging photoelectric spectrometer not only has fast analysis speed, but also greatly improves the accuracy. The appearance of the plasma spectrometer has greatly improved the analysis accuracy, which can reach 10-6 levels, namely, PB, arsenic, tin, antimony, patella and other trace harmful impurities.
Both macro structure testing methods, micro structure testing methods, performance and composition measurement methods are destructive test methods. For some important heavy forgings, their failure methods can not fully meet the requirements of quality inspection. On the one hand, it is too uneconomic; on the other hand, it is mainly to avoid the unilateralism of destructive testing. The development of nondestructive testing technology provides a better and more perfect means for the quality inspection of forgings.