AISI 4340, 880Cx70min, as-quenched.
To study the % of non-M remained.
The non-M appears at the sites which were
Ferrite (solute-poor) bands before Austenization.
The high toughness of ADI comes from the finely interweaving of its L.B.(hard phase) and Austenite(soft phase).
You can imagine how difficult it is for a crack to travel through a matrix like this.
They say I am the best metallurgist in Taiwan. I'd say I am one of the best, and the oldest metallurgist in Taiwan.
No other people in Taiwan still doing the grinding and polishing work at the age of 64. Poor me? Lucky me?