CWB WELDING INSPECTOR STUDY GUIDE QUESTIONS AND
ANSWERS 2025/2026
✔✔How does yield strength vary with grain size? - ✔✔Inversely as the square root of
the grain size.
✔✔Which of the following factors increases the degree of constitutional supercooling?
(a) very slow solidification rate
(b) an alloy with a very narrow solidification range
(c) an alloy with a wide solidification range - ✔✔(c)
✔✔Hot Cracking during welding is more likely in:
(a) pure metals.
(b) alloys with a wide solidification range.
(c) alloys with a very high alloy content. - ✔✔(b)
✔✔Which of the following alloys would you expect to give the highest risk of hot
cracking?
(a) Al-0.1%Cu
(b) Al-3%Cu
(c) Al-8%Cu - ✔✔(b)
✔✔If centerline solidification cracking is occuring in welding a structural steel what is a
likely cause?
(a) electrical extension too long
(b) arc voltage too high
(c) welding current and speed too high
(d) weld too large - ✔✔(c)
✔✔What is the most likely cause of porosity in aluminum welds?
(a) hydrogen
(b) nitrogen
(c) argon
(d) oxygen - ✔✔(a)
✔✔How can porosity due to nitrogen be controlled in welding nickel? - ✔✔By using filler
metal containing titanium.
✔✔What is the most likely cause of porosity in carbon steel welds?
(a) hydrogen from reduction of water
(b) nitrogen
(c) carbon monoxide from reaction of oxygen with carbon
(d) oxygen direct from the air - ✔✔(c)
, ✔✔What elements are included in electrodes or fluxes to control porosity in steel
welds?
(a) silicon, aluminum, manganese
(b) copper, nickel, molybdenum
(c) sulphur, phosphorus, selenium
(d) silica, alumina, magnesia - ✔✔(a)
✔✔What is thermal conductivity divided by specific heat and specific gravity known as?
- ✔✔Thermal diffusivity
✔✔True or False?
A metal with a low thermal conductivity is more likely to reach the maximum melting
efficiency when welded. - ✔✔True
✔✔Would a joint geometry designed for thick stainless steel be perfectly acceptable for
welding thick aluminum? - ✔✔No. Grooves for thick aluminum would have a wider angle
than for stainless steel.
✔✔When welding on a thick plate the cooling rate is proportional to the:
(a) heat input.
(b) inverse of the heat input.
(c) inverse of the square of the heat input. - ✔✔(b)
✔✔From Figure 11.10(Module 20-2014, page 54), estimate the cooling rate for a
submerged arc bead on a 19 mm plate (no preheat) with an energy input of 1.77 kJ/in. -
✔✔16°C/s at 540°C
✔✔Which of the following metals is likely to need the greatest degree of shielding from
the atmosphere during welding?
(a) copper
(b) lead
(c) titanium
(d) steel
(e) gold - ✔✔(c)
✔✔In an electroslag flux the current is carried mainly by:
(a) neutral oxides.
(b) holes.
(c) mobile ions.
(d) thermionic electrons.
(e) free electrons. - ✔✔(c)
✔✔Compared with pure tungsten, a thoriated tungsten electrode is expected to:
(a) get hotter more quickly.
ANSWERS 2025/2026
✔✔How does yield strength vary with grain size? - ✔✔Inversely as the square root of
the grain size.
✔✔Which of the following factors increases the degree of constitutional supercooling?
(a) very slow solidification rate
(b) an alloy with a very narrow solidification range
(c) an alloy with a wide solidification range - ✔✔(c)
✔✔Hot Cracking during welding is more likely in:
(a) pure metals.
(b) alloys with a wide solidification range.
(c) alloys with a very high alloy content. - ✔✔(b)
✔✔Which of the following alloys would you expect to give the highest risk of hot
cracking?
(a) Al-0.1%Cu
(b) Al-3%Cu
(c) Al-8%Cu - ✔✔(b)
✔✔If centerline solidification cracking is occuring in welding a structural steel what is a
likely cause?
(a) electrical extension too long
(b) arc voltage too high
(c) welding current and speed too high
(d) weld too large - ✔✔(c)
✔✔What is the most likely cause of porosity in aluminum welds?
(a) hydrogen
(b) nitrogen
(c) argon
(d) oxygen - ✔✔(a)
✔✔How can porosity due to nitrogen be controlled in welding nickel? - ✔✔By using filler
metal containing titanium.
✔✔What is the most likely cause of porosity in carbon steel welds?
(a) hydrogen from reduction of water
(b) nitrogen
(c) carbon monoxide from reaction of oxygen with carbon
(d) oxygen direct from the air - ✔✔(c)
, ✔✔What elements are included in electrodes or fluxes to control porosity in steel
welds?
(a) silicon, aluminum, manganese
(b) copper, nickel, molybdenum
(c) sulphur, phosphorus, selenium
(d) silica, alumina, magnesia - ✔✔(a)
✔✔What is thermal conductivity divided by specific heat and specific gravity known as?
- ✔✔Thermal diffusivity
✔✔True or False?
A metal with a low thermal conductivity is more likely to reach the maximum melting
efficiency when welded. - ✔✔True
✔✔Would a joint geometry designed for thick stainless steel be perfectly acceptable for
welding thick aluminum? - ✔✔No. Grooves for thick aluminum would have a wider angle
than for stainless steel.
✔✔When welding on a thick plate the cooling rate is proportional to the:
(a) heat input.
(b) inverse of the heat input.
(c) inverse of the square of the heat input. - ✔✔(b)
✔✔From Figure 11.10(Module 20-2014, page 54), estimate the cooling rate for a
submerged arc bead on a 19 mm plate (no preheat) with an energy input of 1.77 kJ/in. -
✔✔16°C/s at 540°C
✔✔Which of the following metals is likely to need the greatest degree of shielding from
the atmosphere during welding?
(a) copper
(b) lead
(c) titanium
(d) steel
(e) gold - ✔✔(c)
✔✔In an electroslag flux the current is carried mainly by:
(a) neutral oxides.
(b) holes.
(c) mobile ions.
(d) thermionic electrons.
(e) free electrons. - ✔✔(c)
✔✔Compared with pure tungsten, a thoriated tungsten electrode is expected to:
(a) get hotter more quickly.
