39. Rapidly cool to 700°C, hold for 25 s, then quench to room temperature. The final microstructure consists of
(A) martensite and pearlite
(B) martensite and proeutectoid ferrite
(C) martensite and bainite
(D) austenite and pearlite
(E) austenite and proeutectoid ferrite.
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統計: 尚無統計資料
統計: 尚無統計資料