Hot hardness
Hot hardness is the hardness of a metal at elevated temperatures. It shows how well the material behaves at high service temperatures and retains its plasticity.
Physikalisch-chemischer Wirkmechanismus
Hot hardness describes the hardness of a metal at ambient temperature. It is a measure of the material's thermal resistance, i.e., its ability to deform plastically at high temperatures without cracking.
Metallurgical Relevance & Welding Risks
During welding, hot hardness can be an important factor. A material with high hot hardness can deform plastically better at high temperatures and show fewer cracks. However, too high a hot hardness can also lead to increased hardness, making the weld harder and more difficult to machine.
Werkstattpraxis & Handlungsanweisungen
To determine the hot hardness of a metal, a special testing device is often used. When welding, it is important to select a material with adequate hot hardness to avoid both cracks and excessive hardness. In general, the hot hardness should be between 200 and 400 HV, depending on the specific application.