Indentation
The test indentation is the permanent plastic deformation on the surface of a material caused by the indenter under test force. It indicates the hardness of the material.
Physikalisch-chemischer Wirkmechanismus
The indentation is created when a hard indenter (e.g., a ball or a pyramid indenter) penetrates the material under a specific load and plastically deforms the surface. This process depends on the hardness of the material and the size of the indenter.
Metallurgical Relevance & Welding Risks
The indentation is used to measure the hardness of a material. Too high hardness can lead to cracks or fractures, while too low hardness makes the material not stable enough. On a weld, it's important that the hardness is consistent and adequate throughout the part.
Werkstattpraxis & Handlungsanweisungen
To measure the indentation, use a hardness tester. The indenter penetrates the material under a set load, and the depth of penetration is measured. For steel, DIN EN ISO 6507 specifies that the indenter should be a ball or pyramid and the load must be between 1.496 N and 2.493 N. Always test on a cooled material to avoid inaccurate results.