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মেটালার্জি MCQ
4. A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as--
allotropic change
heat treatment
recrystallisation
precipitation
12. Carbon steel is--
made by adding carbon in steel
refined from cast iron
an alloy of iron and carbon with varying quantities of phosphorus and sulphur
extensively used for making cutting tools
14. The material mixed before ore is subjected for smelting in the extraction of iron are-
Coke and Silica
Coke and limestone
Limestone and silica
Coke, limestone and silica
15. 'Killed steels are those steels—
which are destroyed by burning
which after their destruction are recycled to produce fresh steel
which are deoxidised in the ladle with silicon and aluminium
in which carbon is compictely burnt
19. A reversible change in the atomic structure of steel with corresponding change in the properties is known as—
molecular change
physical change
allotropic change
solidus change