A. Precipitation of fine alloy carbides at high temperatures
B. Refinement of ferrite grain size by working
C. Decomposition of retained austenite upon heat treatment
D. Precipitation of complex inter-metallic upon heat treatment
Related Mcqs:
- The only suitable method for hardening the low carbon steel is case hardening. Which of the following is a case hardening process ?
A. Cyaniding
B. Sherardizing
C. Spheroidising
D. None of these - Maraging steels derive their strength from the following mechanism ?
A. A fine, highly dislocated and strong martensite
B. Fine dispersions of inter-metallic of Fe, Ni, Ti etc
C. Fine dispersions of alloy carbides in a ferrite matrix
D. Fine dispersions of Fe3 C nucleated on dislocations in austenite - Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about ____________ decibels?
A. 3
B. 30
C. 7
D. 70 - Which of the following is a secondary air pollutant ?
A. Photochemical smog
B. Sulphur dioxide
C. Nitrogen dioxide
D. Dust particles - Which of the following is not a secondary air pollutant ?
A. Ozone
B. Photochemical smog
C. Sulphur dioxide
D. All A., B. & C. - For organic compounds, group contribution method can be used for the estimation of _____________________?
A. Critical properties
B. Specific gravity
C. Specific volume
D. Thermal conductivity - Any substance above its critical temperature exists as _____________________?
A. Saturated vapour
B. Solid
C. Gas
D. Liquid - Isentropic process means a constant _____________________ process ?
A. Enthalpy
B. Pressure
C. Entropy
D. None of these - With increase in temperature, the surface tension of water _____________________?
A. Increases
B. Decreases
C. Remain constant
D. Increases linearly - With increase in the solute concentration, the specific heat of aqueous solutions _____________________?
A. Increases
B. Decreases
C. Remains unchanged
D. Either A. or B.; depends on the type of solution
