Paper
Continuous Cooling Transformation Diagram of Offshore Structural Steel
- Authors:
- Jihao Cheng; Kaiguang Zhang; Yantang Chen
- Abstract
- Continuous cooling rate after final rolling is an important parameter which controls the microstructure and mechanical properties of the high strength low alloy (HSLA) steels extensively used in offshore engineering. Continuous cooling transformation (CCT) diagram was drawn using the dilatation-temperature curve of the offshore HSLA steel cooled at rates covered from 0.1℃/s to 100℃/s after austenitized at 950℃ for 15 minutes. 0.5℃/s was a critical cooling rate for bainite formation. When the cooling rate was set to be less than 0.5℃/s, only ferrite and pearlite were formed. 20.0℃/s was a critical cooling rate for martensite formation. When the cooling rate was higher than 100℃/s only martensite was recognized. The mixed microstructure of ferrite, pearlite and bainite was formed while the cooling rate ranged between 0.5℃/s and 20℃/s. Bainite and martensite were formed in the offshore steel cooled at rates from 20℃/s to 50℃/s. The CCT diagram is a significant tool for steel production.
- Keywords
- CCT Diagram; HSLA Steel; Offshore
- StartPage
- 44
- EndPage
- 49
- Doi