CWB Level 2
What is the outline of harm of a brittle fracture? - ANSSudden speedy fracture below strain
(residual or implemented) in which material well-knownshows very little evidence of ductility or
plastic deformation
What sort of Steel are of primary concern with brittle fractures? - ANSCarbon and coffee alloy
steels. Four hundred series SS also are susceptible
What has a significant have an impact on on durability and resistance to brittle fractures? -
ANSSteel cleanliness and grain size
In maximum instances brittle fractures occur simplest at what temperature? - ANSBelow the
charpy impact transition temperature.(or ductile-to-brittle transition temperature)
The point at which the longevity of the fabric drops off sharply
What kind of gadget or gadgets may be affected for brittle fractures? - ANS*Can occur
throughout ambient temperature hydro trying out because of excessive stresses and low
sturdiness at the trying out temperature
*Most processes run at multiplied temperature so the principle subject is throughout startup,
shutdown, or hydro/tightening trying out.
What is the arrival of a brittle fracture? - ANSTypically appear directly, non branching, and in
large part devoid of any associated plastic deformation. (Although first-class shear lips can be
discovered alongside free adge of the fracture or localized necking round neck of crack.
What is thermal fatigue a end result of ? - ANSCyclic Stress as a result of variations in
temperature.
In thermal fatigue damage takes place as cracking, in which may additionally this occur? -
ANSCan occur everywhere in a metal element where relative movement or differential growth is
confined. Particularly under repeated thermal cycling.
What kind of material can thermal fatigue manifest on? - ANSAll material of construction.
What are a pair however now not all important factors for thermal fatigue? - ANS*Key factors
affecting thermal fatigue are the magnitude of the temperature swing and the frequency (range
of cycles)
*Damage is likewise brought about by using speedy adjustments in floor temperature that
consequences in thermal gradient through the thickness or along the duration of a factor.
, What are some affected gadgets or device of thermal fatigue? - ANS*Major hassle in coke drum
shells
*another instance is the mixture point of warm/cold streams consisting of hydrogen blend points
in hydroprocessing gadgets.
*places wherein condensate comes in contact with steam systems inclusive of de-superheating
or attemporating device
What is the arrival of a thermal fatigue crack? - ANS*Usually initiates at the surface. Generally
wide and regularly packed with oxides due to improved temperature publicity. *May arise as
single or a couple of cracks
*typically propagate transverse to the stress and are typically dagger shaped, transgranular, and
oxide filled.
*Can additionally on occasion be axial, or circumferential or each at the equal place.
How is thermal fatigue pleasant avoided? - ANSThrough layout and operation to reduce thermal
stresses and thermal cycling. Methods of prevention include but no longer all:
Control price of heating and cooling at some stage in startup and shut down
Design that incorporates reduction of strain concentrators, combination grinding of weld profiles
& smooth transitions have to be used.
What are 3 methods of inspection for thermal fatigue? - ANS*Visual Inspection
*MT
*PT
Define Erosion? - ANSAccelerated mechanical elimination of floor fabric as a result of relative
motion between, or effect from solids, drinks, vapors or any aggregate thereof.
Define Erosion-Corrosion? - ANSdescription of the harm that happens when corrosion
contributes to erosion through putting off shielding films or scales, or by means of exposing the
steel floor to further corrosion under the mixed movement of erosion and corrosion.
What type of devices/gadget are stricken by Erosion,
Erosion-Corrosion? - ANSAll sorts of gadget tat are exposed to transferring fluid and/or catalyst
are concern to erosion, erosion-corrosion.
What is the advent of damage for Erosion, Erosion-Corrosion? - ANSLocalized loss in thickness
inside the form of pits, grooves, gullies, waves, rounded holes or valleys. These often showcase
a directional pattern.
What are some methods of prevention/Mitigation for Erosion, Corrosion-Erosion? -
ANS-Improvement in layout. Involving *shape, geometry, material choice
-Improvement of resistance executed thru increasing substrate hardness the usage of more
difficult alloys, tough-going through or surface-hardening remedies.
What is the outline of harm of a brittle fracture? - ANSSudden speedy fracture below strain
(residual or implemented) in which material well-knownshows very little evidence of ductility or
plastic deformation
What sort of Steel are of primary concern with brittle fractures? - ANSCarbon and coffee alloy
steels. Four hundred series SS also are susceptible
What has a significant have an impact on on durability and resistance to brittle fractures? -
ANSSteel cleanliness and grain size
In maximum instances brittle fractures occur simplest at what temperature? - ANSBelow the
charpy impact transition temperature.(or ductile-to-brittle transition temperature)
The point at which the longevity of the fabric drops off sharply
What kind of gadget or gadgets may be affected for brittle fractures? - ANS*Can occur
throughout ambient temperature hydro trying out because of excessive stresses and low
sturdiness at the trying out temperature
*Most processes run at multiplied temperature so the principle subject is throughout startup,
shutdown, or hydro/tightening trying out.
What is the arrival of a brittle fracture? - ANSTypically appear directly, non branching, and in
large part devoid of any associated plastic deformation. (Although first-class shear lips can be
discovered alongside free adge of the fracture or localized necking round neck of crack.
What is thermal fatigue a end result of ? - ANSCyclic Stress as a result of variations in
temperature.
In thermal fatigue damage takes place as cracking, in which may additionally this occur? -
ANSCan occur everywhere in a metal element where relative movement or differential growth is
confined. Particularly under repeated thermal cycling.
What kind of material can thermal fatigue manifest on? - ANSAll material of construction.
What are a pair however now not all important factors for thermal fatigue? - ANS*Key factors
affecting thermal fatigue are the magnitude of the temperature swing and the frequency (range
of cycles)
*Damage is likewise brought about by using speedy adjustments in floor temperature that
consequences in thermal gradient through the thickness or along the duration of a factor.
, What are some affected gadgets or device of thermal fatigue? - ANS*Major hassle in coke drum
shells
*another instance is the mixture point of warm/cold streams consisting of hydrogen blend points
in hydroprocessing gadgets.
*places wherein condensate comes in contact with steam systems inclusive of de-superheating
or attemporating device
What is the arrival of a thermal fatigue crack? - ANS*Usually initiates at the surface. Generally
wide and regularly packed with oxides due to improved temperature publicity. *May arise as
single or a couple of cracks
*typically propagate transverse to the stress and are typically dagger shaped, transgranular, and
oxide filled.
*Can additionally on occasion be axial, or circumferential or each at the equal place.
How is thermal fatigue pleasant avoided? - ANSThrough layout and operation to reduce thermal
stresses and thermal cycling. Methods of prevention include but no longer all:
Control price of heating and cooling at some stage in startup and shut down
Design that incorporates reduction of strain concentrators, combination grinding of weld profiles
& smooth transitions have to be used.
What are 3 methods of inspection for thermal fatigue? - ANS*Visual Inspection
*MT
*PT
Define Erosion? - ANSAccelerated mechanical elimination of floor fabric as a result of relative
motion between, or effect from solids, drinks, vapors or any aggregate thereof.
Define Erosion-Corrosion? - ANSdescription of the harm that happens when corrosion
contributes to erosion through putting off shielding films or scales, or by means of exposing the
steel floor to further corrosion under the mixed movement of erosion and corrosion.
What type of devices/gadget are stricken by Erosion,
Erosion-Corrosion? - ANSAll sorts of gadget tat are exposed to transferring fluid and/or catalyst
are concern to erosion, erosion-corrosion.
What is the advent of damage for Erosion, Erosion-Corrosion? - ANSLocalized loss in thickness
inside the form of pits, grooves, gullies, waves, rounded holes or valleys. These often showcase
a directional pattern.
What are some methods of prevention/Mitigation for Erosion, Corrosion-Erosion? -
ANS-Improvement in layout. Involving *shape, geometry, material choice
-Improvement of resistance executed thru increasing substrate hardness the usage of more
difficult alloys, tough-going through or surface-hardening remedies.
