309. Pick up wrong statement about results of hot working
A.Poor surface finish
B.Improvement in mechanical properties
C.Refinement of grain structure
D.Close tolerances obtained
310. The important mechanical property for a material to be successfully rolled or forged is
A.Brittleness
B.Malleability
C.Elasticity
D.Machinability
311. The important mechanical property of a material for extrusion purposes is
A.Continuity
B.Ductility
C.Elasticity
D.Plasticity
312. The increase in hardness due to cold working is called
A.Cold hardening
B.Hot hardening
C.Work hardening
D.Age-hardening
313. In which type of extrusion process, the movement of the extruded product is in the direction opposite to that of the deforming force
A.Direct
B.Forward
C.Backward
D.Die extrusion
314. Hot working operation is carried at
A.Recrystallisation temperature
B.Near plastic stage temperature
C.Below recrystallisation temperature
D.Above recrystallisation temperature
315. Roll forging
A.Causes a steadily applied pressure instead of impact force
B.Is used to force the end of a heated bar into a desired shape
C.Is a forging operation in which two halves of a rotating die open and close rapidly while impacting the end of heated tube or shell
D.Is forging method for reducing the diameter of a bar and in the process making it longer
Page 45 of 139