309. The hardening of machine tool guideways is usually done by
A.Induction hardening
B.Flame hardening
C.Salt bath furnaces
D.Vacuum hardening

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310. Austempering is the heat treatment process used to obtain greater
A.Hardness
B.Toughness
C.Brittleness
D.Softness

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311. To eliminate the brittteness which occurs due to welding of saw blades, the welded portion must be
A.Toughened
B.Annealed
C.Work hardened
D.Forged

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312. Pick up the wrong statement. Normalising results in
A.Improving mechanical properties
B.Refining coarse grain structure obtained during hot working
C.Improving ductility
D.Improving yield strength

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313. Sheradising is the process in which the objects
A.Are electroplated to obtain wear resistant surface
B.Are treated before painting
C.Are normalised after hardening
D.To be coated and packed in powdered zinc and heated

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314. Selection of a material for a particular use is based on following consideration
A.Service requirements
B.Fabrication characterstic
C.Cost
D.None of the above

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315. Austenite can exist even at sub zero temperature by having high percentage of
A.Chromium
B.Manganese
C.Magnesium
D.Cobalt

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