38. Rapidly cool to 250°C, hold for 1,000 s, then quench to room temperature. The final microstructure consists of
(A) 80% martensite and 20% austenite
(B) 80% martensite and 20% pearlite
(C) 100% martensite
(D) 80% austenite and 20% pearlite
(E) 20% austenite and 80% pearlite.
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統計: 尚無統計資料
統計: 尚無統計資料