Indentation depth
Indentation depth is the vertical penetration of an indenter into the material surface under the applied test force. It is used for hardness calculation in methods like Rockwell.
Physicochemical mechanism of action
Indentation depth measures how deep a hard indenter penetrates into a softer surface. This penetration is caused by applying a fixed test force and gives an indicator of the material's hardness.
Metallurgical relevance & risks in welding
Excessive indentation depth during hardness testing can lead to inaccurate results due to insufficient cooling or incorrect test force. This can cause errors in material selection and overestimation of the material's hardness, posing risks to mechanical strength.
Shop practice & instructions
For accurate indentation depth measurement, it is crucial to set the test force and material correctly. In Rockwell hardness testing, the test force should be set to the specified value (e.g., 150 kgf for HRC). Material cooling after welding must be carefully controlled to achieve a homogeneous and precise indentation depth.