Zusammenfassung der Ressource
Microstructure Constituents
- Austenite
- Face-Centred Cubic
- In Iron-Carbon Alloys
- Evident between 723°C and 1500°C
- Can be Retained at Room Temperature by
Alloy Additions Such as Nickel or Manganese
- Former by Cooling from a Liquid State
- Martensite
- Formed when Cooling Rate from
Austenite is Sufficiently Fast
- Very Hard Constituent due to the Carbon
which is Trapped in the Solid Solution
- Occurs by Sudden Diffusionless Shear Process
- Term not limited to steel
- Bainite
- Formed at cooling rates slower than that for martensite
formation but faster than that for ferrite and pearlite formation
- Two Forms
- Upper Bainite
- Forms between 550°C and 400°C
- Lower Bainite
- Forms between 400°C and 250°C
- Pearlite
- Formed During the Slow Cooling of Iron Alloys
- Can Begin at a Temperature of 1150°C to 723°C
Depending on the Composition of the Alloy
- Formed by Eutectoid Decomposition of Austenite Upon Cooling by
Diffusing of C Atoms when Ferrite and Cementite Grow Continuously