A Metallographic Interpretation of the QLT Heat Treatment of Ferritic Cryogenic Steels.
CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND MINERAL ENGINEERING
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Commercial 5-6Ni steels are toughened for service by a 3-step heat treatment which is sometimes designated the QLT treatment. The present investigation was undertaken to determine why this treatment is necessary and successful. It was concluded that the multi-step heat treatment is necessary because of the low nickel content. The intercritical anneal L serves to create regions of high solute contents along the martensite lath boundaries. The intercritical temper T then precipitates a dense distribution of high solute, stable austenite within these enriched regions.
- Properties of Metals and Alloys
- Fabrication Metallurgy