Q128
A steel specimen containing 0.2 wt.% C is carburized in an atmosphere that maintains a carbon content of 1.2 wt.% C at the surface of the specimen. Given: For carbon diffusion in austenite: D0 = 2.0 × 10-5 m2/s Activation energy for diffusion, Q = 142 kj/mol y erf(y) 0.85 0.7707 0.90 0.7970 0.95 0.8209 What is the depth (in (μm) from the surface of the specimen at which a composition of 0.4wt.% C is obtained after carburizing at 870°C for 10 h?
A steel specimen containing 0.2 wt.% C is carburized in an atmosphere that maintains a carbon content of 1.2 wt.% C at the surface of the specimen.
Given:
For carbon diffusion in austenite: D0 = 2.0 × 10-5 m2/s
Activation energy for diffusion, Q = 142 kj/mol
What is the depth (in (μm) from the surface of the specimen at which a composition of 0.4wt.% C is obtained after carburizing at 870°C for 10 h?
Given:
For carbon diffusion in austenite: D0 = 2.0 × 10-5 m2/s
Activation energy for diffusion, Q = 142 kj/mol
| y | erf(y) |
| 0.85 | 0.7707 |
| 0.90 | 0.7970 |
| 0.95 | 0.8209 |
A.
15
B.
84
C.
113
D.
875
AnswerAnswer: Option D
Solution
Answer: Option D
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