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Continuous Cooling Transformation Diagram for Welding

The CCT diagram shows how the microstructure forms at different cooling rates. It helps understand martensite, bainite, and ferrite.

Physicochemical Mechanism of Action

The CCT diagram shows the dependence of the microstructure on the cooling rate after welding. Rapid cooling produces martensite, slow cooling ferrite or bainite.

Metallurgical Relevance & Welding Risks

Wrong cooling rates can lead to fine microstructures like martensite, which are hard and crack-sensitive. Slow cooling can lead to grain growth and reduced strength.

Workshop Practice & Action Instructions

Use the CCT diagram to control the cooling rate. For high-strength alloys (e.g., HSS), cool slowly (t8/5 > 25 s); for soft alloys (e.g., SS), cool faster (t8/5 < 5 s).

MetallurgieSchweißtechnik

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