4 Refer to the attached TT diagram of an Ausl4340 Steel dete

4 Refer to the attached TT diagram of an Ausl4340 Steel, determine the type(s) of microconstituent (phase) that will be produced by the heat treatments designated as a, b, c, and d in the figure provided. Also indicate the approximate percentage of each phase in your answer.

Solution

From vertical line to point a.

Martensite microstructure (100%)

From point a to point d.

Martensite + Bainite

From point d to point b.

Martensite + Bainite + proeutectiod Ferrite

From point d to point c.

Martensite + Bainite + proeutectiod Ferrite + pearlite

From point c to right vertical line

Proeutectiod Ferrite + pearlite