Martensitic Transformation Stage
The martensite range is the temperature span where austenite is rapidly cooled and converts to glass-hard martensite. This can lead to hard, crack-prone weld areas.
Physicochemical Mechanism of Action
Austenite transforms into martensite in a cool temperature range (Ms to Mf). This process is diffusionless and occurs very quickly, resulting in a glass-hard structure.
Metallurgical Relevance & Welding Risks
Too rapid cooling can lead to martensite stages, creating hard and crack-prone weld areas. This increases the risk of hot cracks and reduces the toughness of the weld.
Workshop Practice & Action Instructions
To avoid martensite stages, the cooling rate should be controlled. The critical time t8/5 should be between 5 and 25 seconds. For metals with high carbon content, slow cooling (t8/5 > 25 s) is recommended to coarsen the structure and increase toughness.