Question
Download Solution PDFOn completion of heat treatment, the austenite structure would be retained if
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFThe martensite start and finish temperature depends upon the carbon content of the steel. When steels of more than 0.65% carbon are quenched the austenite-to-martensite transformation does not end at room temperature (20°C) but at some lower temperature even at temperatures much lower than 0°C. Consequently after these steels are quenched to room temperature a portion of the austenite will remain untransformed this untransformed austenite is called retained austenite.
Retained austenite can be transformed into martensite by
- Mechanical transformation of retained austenite by application of high stresses.
- It is also done by sub-zero treatment i.e. cooling below -70°C or by tempering.
The amount of retained austenite increases with increasing hardening temperature.
Last updated on Jul 2, 2025
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