344. High ratios of surface to mass tend to
A.Produce smaller depths of hardening
B.Produce greater depths of hardening
C.Have no effect on depth of hardening
D.Have unpredictability about depth of hardening

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345. Cast iron contains carbon
A.= 2%
B.< 0.8%
C.< 2%
D.> 2%

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346. Spherodite is the structure obtained by
A.Quenching austenite
B.Quenching austenite and then heating into the range of 200° to 375°C
C.Quenching austenite and then heating into the range of 375° to 660°C
D.Quenching austenite and then heating into the range of 660° to 700°C

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347. The following structure is obtained by austempering process of heat treatment
A.Troostite
B.Martensite
C.Sorbite
D.Bainite

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348. Steels are primarily designated according to
A.Iron content
B.Carbon content
C.Alloying elements
D.Hardness

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349. The structure obtained by heating a steel above critical point and then quenching in water is
A.Martensite
B.Sorbite
C.Acicular
D.Bainite

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350. Sorbite is the structure obtained by
A.Quenching austenite
B.Quenching austenite and then heating into the range of 200° to 375°C
C.Quenching austenite and then heating into the range of 375°-660°C
D.Quenching austenite and then heating into the range of 600°-700°C

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