A steel contains 38.5 mass % pro-eutectoid ferrite and 61.3 mass % austenite at eutectoid temperature (723°C). The carbon content of steel, in mass %, is

Which one of the following four addresses is NOT EXACTLY the same as the one given below? Woods, Greg/Heflinger, Joan 613 Lafayette Avenue Crawfordsville, Indiana 47933 (317) 3622781 (i) Woods, Greg/Heflinger, Joan 613 Lafayette Avenue Crawfordsville, Indiana 47933 (317) 3622781 (ii) Woods, Greg/Hefinger, Joan 613 Lafayette Avenue Crawfordsville, Indiana 47933 (317) 3622781 (iii) Woods, Greg/Heflinger, Joan 613 Lafayette Avenue Crawfordsville, Indiana 47933 (317) 3622781 (iv) Woods, Greg/Heflinger, Joan 613 Lafayette Avenue Crawfordsville, Indiana 47933 (317) 3622781

A

i

B

ii

C

iii

D

iv

A binary phase diagram of components P and Q displays an eutectoid reaction with terminal solid solutions a on the P rich side and β on the Q rich side. At the eutectoid temperature, the solubilities of Q in a and β are 5 and 90 wt% respectively. The densities of α and β phases are 9.5 and 2.49 gm/cm³ respectively.
At the eutectoid point, the alloy has α and β in the weight ratio 1 : 1. The eutectoid point occurs at composition . . . . . . . . wt % Q.

A

46

B

47.5

C

50

D

52.5

Combined carbon content in iron and steel is determined by treating the sample with dilute HNO₃. So that combined carbon forms a soluble brown nitrated compound, the intensity of which is matched with that of a standard sample of similar composition treated under similar condition. The intensity of color produced is proportional to the carbon content of iron of steel sample. This method of combined carbon determination is called the

A

Strohlein method

B

Eggertz method

C

Combustion method

D

None of these

The two surfaces of a 5 mm thick plate of carbon steel are maintained at a carbon concentration of 10⁴ mol. m^-3 on one side and zero concentration on the other side. Taking the diffusion coefficient of carbon in austenite to be 10^-11 m^-2.s^-1, the steady state flux (mol.m^-3.s^-1) through the thickness of the steel is

A

10^-5

B

2 × 10^-5

C

4 × 10^-5

D

6 × 10^-5

A eutectoid steel is slowly cooled from a temperature of 750°C to a temperature just below 727°C. Calculate the percentage of ferrite and cementite.

A

88.3% and 11.7%

B

70% and 30 %

C

85.4% and 14.6%

D

20% and 20%

What is the monoisotopic and average mass of valine? Given data: Mass of the most abundant isotope of Carbon (C°)=12.0000, Mass of most abundant isotope of Hydrogen (H°)=1.0078, Mass of most abundant isotope of Oxygen (O°)=15.9949, Mass of most abundant isotope of Nitrogen (N°)=14.0031, The average mass of Carbon (C)=12.011, The average mass of Hydrogen (H)=1.008, The average mass of Oxygen (O)=15.999, The average mass of Nitrogen (N)=14.007.

A

99.068 and 99.2361

B

99.216 and 99.326

C

99.111 and 99.321

D

99.068 and 99.132

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

A

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? 15

B

84

C

113

D

875

In Eutectoid reaction a solid phase transforms into two other solid phases upon cooling. Which one of the following is correct in the case of Eutectoid reaction occurring in Iron-Carbon phase diagram?

A

Austenite converts to Ferrite and Cementite

B

Ferrite converts to Cementite and Martensite

C

Cementite converts to Austenite and Ferrite

D

Martensite converts to Ferrite and Cementite

Rapid quenching of eutectoid steel ___________ transforms the austenite into martensite.

A

At room temperature

B

Below 320oC

C

At 550oC

D

Above 723oC

What is the carbon content in pearlite or eutectoid steel

A

Below 0.8%

B

0.80%

C

1%

D

1.50%

A steel contains 38.5 mass % pro-eutectoid ferrite and 61.3 mass % austenite at eutectoid temperature (723°C). The carbon content of steel, in mass %, is

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