Test force levels in hardness testing
Test force levels in hardness testing define the static load from micro, low-load, to macro-hardness ranges to avoid measurement errors due to unwanted substrate or edge zone influences. Each level adapts to the specimen thickness.
Physical-Chemical Mechanism of Action
The test force levels in hardness testing determine the static load applied to the material. These levels range from micro-hardness (low loads) through low-load hardness (medium loads) to macro-hardness (high loads). Choosing the right test force level is crucial for an accurate measurement, as it determines the hardness of the material in different areas.
Metallurgical Relevance & Welding Risks
Incorrect selection of the test force level can lead to measurement errors. At too low a load, edge zones or subsurface defects can influence the hardness measurement, while too high loads can potentially damage the material or be misinterpreted. This can lead to incorrect analysis of weld seam issues and inaccurate material selections.
Workshop Practice & Instructions
Choose the test force level according to the sample thickness. For thinner samples (e.g., ≤ 1 mm), use micro-hardness; for medium samples (e.g., 2-5 mm), use low-load hardness; and for thin weld seam samples, use macro-hardness. Ensure that the test is carried out with a calibrated device to minimize measurement errors.