TTT Diagrams

What is the austenite temperature?

• 727 C

• 1147 C

• Room Temperature

• 540 C

What is the threshold temperature that divides Bainite from Pearlite?

• 540 C

• Room Temperature

• 1147 C

• 727 C

Which microstructure is NOT formed when cooling down your piece?

• Bainite

• Pro-Euctectoid Ferrite

• Austenite

• Martensite

Which microstructure formed when reheating your piece?

• Pearlite

• Spheroidite

• Tempered Martensite

• Pro-euctectoid Ferrite

Where can you find the hardness scale of your TTT Diagram?

• Top of the figure

• Left of the figure

• Right of the figure

• Bottom of the figure

What is the strongest microstructure?

• Pearlite

• Martensite

• Tempered Martensite

• Bainite

All cooling processes start with austenite.

• True

• False

Spheroidite forms when reheating at relative high temperatures for 15 - 30 hrs.

• True

• False

Under the right conditions, all microstructures transform to spheroidite upon reheating.

• True

• False

Heat treat 6150 Steel. Quick cool to 490 C/ Hold 200 sec/ Quench to RT. Identify the resulting microstructure.

• 100 % Spheroidite

• 100 % Temp. Martensite

• 50% Pearlite

  50% Bainite

• 50% Bainite

  50% Martensite