CWB Welding Inspector Level III Study
Guide
A Wide solidification range and fast growth price in the course of solidification will
encourage:
(a) planar increase.
(b) equilibrium situations.
(c) no constitutional supercooling.
(d) dendritic increase.
(e) eutectic formation. - ANS-(d)
Can pressure growing older in low carbon steels take place at room temperature? - ANS-Yes
Centerline hot cracking im much more likely with:
(a) shallow, spherical welds.
(b) brief weld swimming pools.
(c) extensive groove angles.
(d) deep, slender welds.
(e) vertical welds. - ANS-(d)
Compared with natural tungsten, a thoriated tungsten electrode is expected to:
(a) get hotter extra fast.
(b) absorb greater electrons.
(c) have a shorten life.
(d) function at a lower temperature for the equal contemporary.
(e) emit greater ions. - ANS-(d)
Electricity can be performed through:
(a) atoms and electrons.
(b) electrons and ions.
(c) most effective ions. - ANS-(b)
From Figure eleven.10(Module 20-2014, page fifty four), estimate the cooling charge for a
submerged arc bead on a 19 mm plate (no preheat) with an power enter of one.77 kJ/in. -
ANS-sixteen°C/s at 540°C
Hot Cracking throughout welding is more likely in:
(a) natural metals.
(b) alloys with a huge solidification variety.
(c) alloys with a very high alloy content material. - ANS-(b)
How can porosity due to nitrogen be managed in welding nickel? - ANS-By using filler metal
containing titanium.
How does yield energy vary with grain size? - ANS-Inversely because the rectangular root of
the grain length.
How many levels are there in a eutectic- one or two? - ANS-Two
If centerline solidification cracking is occuring in welding a structural steel what's a likely
motive?
(a) electrical extension too long
(b) arc voltage too high
, (c) welding cutting-edge and velocity too excessive
(d) weld too big - ANS-(c)
If FCC iron has a denser structure than BCC iron, why does it have a better solubility for
carbon? - ANS-The favored website online for carbon in BCC iron is smaller than that during
FCC iron.
If two metals have whole mutual stable solubility how many levels are shaped in the strong-
one or two? - ANS-One
In an electroslag flux the contemporary is carried in particular by way of:
(a) impartial oxides.
(b) holes.
(c) cell ions.
(d) thermionic electrons.
(e) free electrons. - ANS-(c)
Increasing the initial plate temperature (preheat):
(a) has no impact on the cooling price.
(b) reduces the weld warmness input.
(c) reduces the cooling price.
(d) causes narrower isotherms.
(e) improves the arc efficiency. - ANS-(c)
Multiplication and subsequent congestion of transferring dislocations reasons:
(a) elastic extension.
(b) work or stress hardening.
(c) a drop within the yield pressure. - ANS-(b)
Nickel and copper have complete strong solubility. Copper has a decrease melting point then
nickel. If a 50/50 Cu-Ni alloy is cooled from the liquid what will be the composition of the first
stable to shape?
(a) 50% Cu
(b) less than 50% Cu
(c) Pure Cu
(d) Pure Ni
(e) more than 50% Cu - ANS-(b)
Porosity in welds because of a specific gasoline is much more likely if the:
(a) solubility of the gasoline at the freezing point is tons lower than at higher temperatures.
(b) solubility of the gasoline on the freezing point is very excessive.
(c) fuel does not dissolve inside the liquid.
(d) solubility is impartial of temperature.
(e) gas has a high solubility in the strong. - ANS-(a)
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the loose strength of oxide formation against temperature.
(c) shows the fee of oxidation of metals in opposition to temperature. - ANS-(b)
The presence of close-packed planes in FCC metals offers a lot of them the special
belongings of:
(a) top high-temperature power.
(b) the potential to go through significant plastic deformation.
(c) brittleness at low temperatures.
(d) complete solubility with all other metals.
(e) small grains. - ANS-(b)
Guide
A Wide solidification range and fast growth price in the course of solidification will
encourage:
(a) planar increase.
(b) equilibrium situations.
(c) no constitutional supercooling.
(d) dendritic increase.
(e) eutectic formation. - ANS-(d)
Can pressure growing older in low carbon steels take place at room temperature? - ANS-Yes
Centerline hot cracking im much more likely with:
(a) shallow, spherical welds.
(b) brief weld swimming pools.
(c) extensive groove angles.
(d) deep, slender welds.
(e) vertical welds. - ANS-(d)
Compared with natural tungsten, a thoriated tungsten electrode is expected to:
(a) get hotter extra fast.
(b) absorb greater electrons.
(c) have a shorten life.
(d) function at a lower temperature for the equal contemporary.
(e) emit greater ions. - ANS-(d)
Electricity can be performed through:
(a) atoms and electrons.
(b) electrons and ions.
(c) most effective ions. - ANS-(b)
From Figure eleven.10(Module 20-2014, page fifty four), estimate the cooling charge for a
submerged arc bead on a 19 mm plate (no preheat) with an power enter of one.77 kJ/in. -
ANS-sixteen°C/s at 540°C
Hot Cracking throughout welding is more likely in:
(a) natural metals.
(b) alloys with a huge solidification variety.
(c) alloys with a very high alloy content material. - ANS-(b)
How can porosity due to nitrogen be managed in welding nickel? - ANS-By using filler metal
containing titanium.
How does yield energy vary with grain size? - ANS-Inversely because the rectangular root of
the grain length.
How many levels are there in a eutectic- one or two? - ANS-Two
If centerline solidification cracking is occuring in welding a structural steel what's a likely
motive?
(a) electrical extension too long
(b) arc voltage too high
, (c) welding cutting-edge and velocity too excessive
(d) weld too big - ANS-(c)
If FCC iron has a denser structure than BCC iron, why does it have a better solubility for
carbon? - ANS-The favored website online for carbon in BCC iron is smaller than that during
FCC iron.
If two metals have whole mutual stable solubility how many levels are shaped in the strong-
one or two? - ANS-One
In an electroslag flux the contemporary is carried in particular by way of:
(a) impartial oxides.
(b) holes.
(c) cell ions.
(d) thermionic electrons.
(e) free electrons. - ANS-(c)
Increasing the initial plate temperature (preheat):
(a) has no impact on the cooling price.
(b) reduces the weld warmness input.
(c) reduces the cooling price.
(d) causes narrower isotherms.
(e) improves the arc efficiency. - ANS-(c)
Multiplication and subsequent congestion of transferring dislocations reasons:
(a) elastic extension.
(b) work or stress hardening.
(c) a drop within the yield pressure. - ANS-(b)
Nickel and copper have complete strong solubility. Copper has a decrease melting point then
nickel. If a 50/50 Cu-Ni alloy is cooled from the liquid what will be the composition of the first
stable to shape?
(a) 50% Cu
(b) less than 50% Cu
(c) Pure Cu
(d) Pure Ni
(e) more than 50% Cu - ANS-(b)
Porosity in welds because of a specific gasoline is much more likely if the:
(a) solubility of the gasoline at the freezing point is tons lower than at higher temperatures.
(b) solubility of the gasoline on the freezing point is very excessive.
(c) fuel does not dissolve inside the liquid.
(d) solubility is impartial of temperature.
(e) gas has a high solubility in the strong. - ANS-(a)
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the loose strength of oxide formation against temperature.
(c) shows the fee of oxidation of metals in opposition to temperature. - ANS-(b)
The presence of close-packed planes in FCC metals offers a lot of them the special
belongings of:
(a) top high-temperature power.
(b) the potential to go through significant plastic deformation.
(c) brittleness at low temperatures.
(d) complete solubility with all other metals.
(e) small grains. - ANS-(b)
