Thermal Cooling Parameter
The thermal cooling parameter is a quantity for describing heat dissipation during welding. It helps determine the critical t8/5 time.
Physical-Chemical Mechanism of Action
The thermal cooling parameter describes how fast a workpiece cools during welding. It is important for understanding microstructure behavior and the risk of cracks or hardness problems.
Metallurgical Relevance & Risks in Welding
Too fast cooling (short t8/5 time) can lead to hard martensite, increasing crack susceptibility and hot cracking risk. Too slow cooling (long t8/5 time) coarsens the grain and reduces steel toughness.
Workshop Practice & Instructions
To correctly assess the thermal cooling parameter, note these values:
• t8/5 time should be between 5 and 25 seconds for a balanced microstructure.
• Monitor the temperature curve during welding and adjust cooling systems accordingly.