Inspection of the appearance quality is generally a non-destructive test, usually with the naked eye or a low magnification magnifying glass, and if necessary, non-destructive testing. For the inspection of internal quality, due to the requirements of its inspection content, some must use destructive testing, that is, the commonly used anatomical tests, such as low-spectrum test, fracture test, high-fold tissue test, chemical composition analysis and mechanical property test. Some can also use non-destructive testing methods, and in order to more accurately evaluate the quality of forgings, destructive testing methods and non-destructive testing methods should be combined with each other. In order to analyze the quality of forgings from a deeper level, the mechanistic research work should be assisted by transmissive or scanning electron microscopes and electron probes.
Generally, the internal quality inspection method of forgings can be summarized as: macroscopic inspection method, microstructure inspection method, mechanical property test, chemical composition analysis method and non-destructive testing method.
Macroscopic tissue inspection is a test that uses a visual or low magnification magnifying glass (generally multiples below 30×) to observe and analyze the low-fold tissue characteristics of forging. Common methods for macroscopic inspection of forgings are low-corrosion methods (including thermal erosion, cold etching, and electrolytic corrosion), fracture test, and sulfur printing.