Hardness test:

Hardness testing is one of the important indicators for testing material properties, and it is also one of the fastest and most economical methods. The reason why it can become a common method for mechanical property testing is that hardness testing can reflect the chemical composition, structure and processing technology of materials. difference. Often used as a means of supervision in all walks of life. For example, in steel materials, when martensite is formed, the lattice distortion is increased due to the dissolution of supersaturated carbon atoms, which increases the dislocation density, thereby significantly reducing the plastic deformation ability, which is the reason for the high hardness of martensite. . Obviously, the higher the carbon content, the greater the degree of distortion, and the higher the hardness. After quenching of steels with different carbon content, the hardness value and the martensite content and its carbon content have a wide range. Good correspondence, the hardness of quenched steel after tempering depends on the tempering temperature and holding time. The higher the tempering temperature and the longer the holding time, the lower the hardness. Therefore, the hardness test can be used to study the phase transformation of steel and as a means to detect the effect of heat treatment of steel.

Spectral inspection:

The method of identifying a substance and determining its chemical composition and relative content according to its spectrum is called spectral analysis. Its advantages are sensitive and rapid. The light reflected off the surface of an object can be measured with a spectrometer. The seven-color light in sunlight is the part that the naked eye can distinguish (visible light), but if sunlight is decomposed by a spectrometer and arranged according to wavelength, visible light only occupies a small range in the spectrum, and the rest are spectrums that cannot be distinguished by the naked eye, such as infrared rays, microwaves , UV rays, X-rays, etc. The optical information is captured by the spectrometer, developed with a photographic film, or displayed and analyzed by a computerized automatic display numerical instrument, so as to detect what elements are contained in the article.

Metallographic examination:

Metallographic analysis is one of the important means of experimental research on metal materials. Using the principle of quantitative metallography, the three-dimensional space morphology of the alloy structure is determined by the measurement and calculation of the metallographic microstructure of the two-dimensional metallographic sample's polished surface or thin film. Quantitative relationship between alloy composition, structure and properties.

Application:

1. Metallographic inspection of welding;

2. Metallographic inspection of cast iron;

3. Heat treatment quality inspection;

4. Microstructure inspection and evaluation of various metal products and raw materials;

5. Low magnification defect inspection of cast iron, cast steel, non-ferrous metals and raw materials;

6. Metal hardness (HV, HRC, HB, HL) determination, grain size rating;

7. Determination of non-metallic inclusion content;

8. Determination of the depth of decarburized layer/carburized hardened layer, etc.