Question:
Sub-Zero treatment of steel is carried out for
Sub-Zero treatment of steel is carried out for
Show Hint
Sub-Zero "finishes" the job. It transforms the soft retained austenite that room-temperature quenching missed.
Updated On: Jul 4, 2026
- Converting Austenite to Bainite
- Converting retained Austenite to pearlite
- Converting retained Austenite to Ferrite
- Converting retained Austenite to Martensite
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Step 1: Concept In many alloy steels, the Martensite Finish ($M_{f}$) temperature is below room temperature.
Step 2: Meaning Retained austenite is the portion of austenite that fails to transform during initial quenching to room temperature.
Step 3: Analysis Retained austenite is soft and unstable, which can cause dimensional changes or reduced hardness over time.
Step 4: Conclusion Cooling the steel to sub-zero temperatures (e.g., in liquid nitrogen) forces the completion of the transformation of retained austenite into martensite. Final Answer: (D)
Step 2: Meaning Retained austenite is the portion of austenite that fails to transform during initial quenching to room temperature.
Step 3: Analysis Retained austenite is soft and unstable, which can cause dimensional changes or reduced hardness over time.
Step 4: Conclusion Cooling the steel to sub-zero temperatures (e.g., in liquid nitrogen) forces the completion of the transformation of retained austenite into martensite. Final Answer: (D)
Was this answer helpful?
0
0
Top AP ECET Metallurgical Eng Metallurgical Engineering Questions
- The crushing efficiency of a crusher is the ratio of
- Grindability of a material does not depend upon its
- Copper deposits are found in India at the following location
- Electrochemical corrosion can occur only if _____________ is present in contact with the metal.
- Hoop's process is predominantly used for the electrolytic refining of
View More Questions
Top AP ECET Metallurgical Eng Heat Treatment Processes Questions
- Improvement of machinability in high carbon steel is obtained by
- Pearlite in a steel is formed from
- The product of diffusionless transformation is
- The characteristics of martensite formation does not include
- Martensite in a mild steel is obtained by
View More Questions
Top AP ECET Metallurgical Eng Questions
- Order of the matrix $\begin{bmatrix} 1 & 6 \\ 2 & 0 \\ 7 & -1 \end{bmatrix}$ is
- If two rows (or columns) of a determinant of order 3 are identical then the value of determinant is
- Co-factor of -4 in $\begin{vmatrix} 1 & 2 & 3 \\ -4 & 3 & 6 \\ 2 & -7 & 9 \end{vmatrix}$ is
- The Matrix $\begin{bmatrix} a & h & g \\ h & b & f \\ g & f & c \end{bmatrix}$ is
- If $A = \begin{bmatrix} 0 & 0 & 1 \\ 0 & 1 & 0 \\ 1 & 0 & 0 \end{bmatrix}$ then $(A^{-1}) =$
View More Questions