Question

Question One
a) With the aid of appropriate sketches, explain how the following factors influence material creep
behaviour

i. ii. iii. iv.

Exposure time Applied mechanical load. Exposure temperature and Material mechanical properties,

[4 marks]
b) In a typical creep test, load level (typically below material yield strength) and temperature are
kept constant while specimen deformation is monitored with time. From the deformations,
strains are computed and plotted as a function of time. Three (3) stages may typically be
observed.

i. ii. iii. iv.

Sketch a typical strain-time curve for the creep life of a component. On the sketch in (i), indicate instantaneous, primary, secondary and tertiary stages. For the primary, secondary and tertiary stages, sketch the strain-rate time curve. Sketch how the sketch in (i) would change when temperature is increased.

[4x4 marks

Answer 1

ANSWER : PAGE GIVEN CONSIDERATIONS How the factors inflience material reep behaviour & EX POSURE Creep is the fime depandast phenomenon . the exposure time Creep depends on ie de at Com - IKT e db (10) APPLIED MECHANICAL LOAD! Effect of applied load on creep is shown infigo ago 2 OR strain E time strain rate increases with load applied Cien) EXPOSURE TEMPERATURE Effect of exposure temperature is a T3 T2 T2 >7, 1 Strain time → is temperature strain rate increases with increase

MATERIAL (PAGE 2 MECHANICAL Prorecte equation get from we de e-Qlk As grain size increases strain rate due to creeping decreases. Creep lite of a component T3 T2 T>T T Strain E Primary Secondary Tentary 1 time increases in with increase in temperature, strain rate primary region. Tentary secondary primary Strain Rate time strain rate is almost constant in sundary region. assired for gut 4 rub As per chego guidelines of have parts question. please upvote its for me → necessary