Indentation Diagonal
The indentation diagonal is the length of the line connecting the opposite corners of a Vickers indentation. It is used to calculate the deformed surface area.
Physical-chemical mechanism of action
The indentation diagonal is the measurement of the visible line connections between the corner points of a Vickers indentation. This indentation is made on the metal by a heavy pyramid crystal under a fixed load weight and deforms its surface.
Metallurgical relevance & risks in welding
The indentation diagonal provides information about the hardness and strength of the material. A too large indentation diagonal value can indicate a too hard or too uneven deformation, which can lead to cracks or destruction in the weld. If the hardness is too soft, the service life of the components can be shortened.
Workshop practice & instructions
To measure the indentation diagonal, a microscope is used. The length of the line connections between the corner points of the Vickers indentation is measured in micrometers (µm). A typical value for a robust steel grade could be 200 µm. If the values are unevenly high, the welding parameters should be checked and adjusted if necessary.