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CWB Welding Inspector Level 3 study materials
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CWB Welding Inspector Level 3 practice questions

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Question 1Welding processes, consumables and metallurgy

In the CSA electrode designation E4918, what does the suffix "18" specify?

  1. A fast-freeze covering intended for vertical-down welding
  2. A cellulosic covering intended for deep penetration
  3. A low-hydrogen covering containing iron powder Correct answer.
  4. A rutile covering intended for a smooth arc

Explanation

In CSA W48, the E49xx designation gives the minimum tensile strength in the first two digits, the welding position in the third digit, and the covering type in the last two. The suffix 18 identifies a low-hydrogen, iron-powder covering with a basic slag system. These electrodes require dry storage and baking after exposure because moisture raises weld hydrogen.

Question 2Welding processes, consumables and metallurgy

Which GMAW metal-transfer mode is characterized by the electrode contacting the weld pool and the arc extinguishing repeatedly at low current?

  1. Globular transfer
  2. Pulsed-spray transfer
  3. Spray transfer
  4. Short-circuiting transfer Correct answer.

Explanation

Short-circuiting transfer uses relatively low current and voltage, so the wire touches the pool, extinguishes the arc briefly, and then pinches off a droplet. This mode is widely used for thin sections and out-of-position work. Spray, globular, and pulsed-spray transfer do not rely on repeated pool contact.

Question 3Welding processes, consumables and metallurgy

Which workshop condition most directly raises the risk of hydrogen-assisted cracking in a high-strength steel weld?

  1. Depositing with damp, unbaked low-hydrogen electrodes Correct answer.
  2. Using a longer electrode stick-out during welding
  3. Increasing the travel speed slightly during the pass
  4. Preheating the joint to 150 °C before welding

Explanation

Moisture on or in a low-hydrogen electrode dissociates in the arc and supplies hydrogen to the weld metal. Hydrogen diffuses to stressed regions in high-strength steel and can initiate delayed cracking. Electrodes must be stored dry and baked according to the manufacturer's instructions before use.

Question 4Welding processes, consumables and metallurgy

Which practice is acceptable when recycling unused submerged-arc welding flux?

  1. Using it without checking for moisture pickup
  2. Screening out fines and foreign matter before reuse Correct answer.
  3. Blending it with new flux without screening or drying
  4. Adding water to reduce dust during handling

Explanation

Recycled SAW flux must be free of slag, dirt, and excessive fines, and it must be dry. Screening restores a suitable particle-size distribution for consistent coverage and gas flow. Moisture control is critical because hydrogen from flux can cause cracking and porosity.

Question 5Welding processes, consumables and metallurgy

A carbon steel has a carbon equivalent (IIW) of 0.45 and a thickness of 25 mm. What does this most strongly indicate for welding?

  1. No preheat is needed because the carbon equivalent is moderate.
  2. Preheat and controlled heat input are needed. Correct answer.
  3. The steel is austenitic stainless steel and needs no preheat.
  4. The weld should be quenched immediately after deposition.

Explanation

A carbon equivalent of 0.45 is above the usual threshold at which hardenability and hydrogen cracking risk become significant, especially in 25 mm plate. Preheat slows cooling and helps hydrogen escape, while controlled heat input limits hard HAZ formation. The exact preheat should follow the applicable code or procedure qualification.

Question 6Welding processes, consumables and metallurgy

Why is alternating current commonly used for gas tungsten arc welding of aluminum?

  1. It prevents tungsten contamination completely.
  2. It eliminates the need for filler metal entirely.
  3. It maximizes penetration and produces a very narrow arc.
  4. It combines oxide cleaning with good penetration. Correct answer.

Explanation

In AC GTAW, the electrode-positive half-cycle breaks up and removes the refractory aluminum oxide, while the electrode-negative half-cycle provides deeper heating and limits tungsten overheating. This balance is why AC is preferred over direct current for aluminum.

Question 7Welding processes, consumables and metallurgy

Which statement correctly distinguishes self-shielded FCAW from gas-shielded FCAW?

  1. Self-shielded FCAW needs no external shielding gas. Correct answer.
  2. Self-shielded FCAW uses only DCEN and cannot be used outdoors.
  3. Self-shielded FCAW uses external CO2 and a solid wire.
  4. Self-shielded FCAW requires an argon-rich shielding gas.

Explanation

Self-shielded flux-cored wires contain ingredients that generate shielding gas and slag without an external supply. This makes them useful for field work and windy conditions. Gas-shielded FCAW, by contrast, requires a separate shielding gas and usually a tubular wire.

Question 8Welding processes, consumables and metallurgy

What is the principal purpose of post-weld heat treatment of a carbon steel pressure vessel weld?

  1. To increase the yield strength of the weld metal significantly
  2. To relieve residual stress and temper hard HAZ regions Correct answer.
  3. To refine the grain structure by means of rapid cooling
  4. To introduce beneficial compressive residual stress into the joint

Explanation

PWHT is performed to reduce residual stresses from welding and to temper hard microstructures in the heat-affected zone. Lower residual stress improves dimensional stability and resistance to cracking, while tempering improves toughness. It is not a strengthening treatment for carbon steel.

Question 9Welding processes, consumables and metallurgy

A fully austenitic stainless steel weld shows centerline solidification cracking. Which condition most likely contributes?

  1. High ferrite content with a balanced bead shape
  2. High sulfur and phosphorus with a deep, narrow bead Correct answer.
  3. Low heat input with a high manganese content
  4. Low sulfur and phosphorus with a wide, shallow bead

Explanation

Solidification cracking occurs when low-melting solute-rich films remain at grain boundaries while the weld is strained during cooling. Sulfur and phosphorus strongly segregate and extend the freezing range, and a deep, narrow bead concentrates shrinkage strain at the centerline. Fully austenitic stainless steels lack ferrite to dissolve those impurities.

Question 10Welding processes, consumables and metallurgy

Increasing heat input while keeping preheat constant generally has what effect on the coarse-grained HAZ of a high-strength low-alloy steel?

  1. It reduces hydrogen diffusion into the weld metal.
  2. It lowers hardenability and eliminates all cracking risk.
  3. It refines grain size through faster cooling.
  4. It widens the HAZ and lowers toughness. Correct answer.

Explanation

Higher heat input slows cooling and raises the time at elevated temperature, so the HAZ grows wider. In high-strength low-alloy steels this can coarsen austenite grains and produce tougher or more brittle transformation products depending on composition. Heat input must therefore be balanced against hydrogen control and mechanical property requirements.

Question 11Welding processes, consumables and metallurgy

A covered electrode classified as E7018 has been left uncovered in a humid shop for two days. What is the correct action before it is used on a critical joint?

  1. Redry it as recommended by the manufacturer Correct answer.
  2. Dip it in water, then let it air-dry
  3. Hold it in a cabinet at about 50 °C for one hour
  4. Use it as it is, provided the coating still looks dry

Explanation

E7018 has a basic, low-hydrogen coating that readily absorbs moisture from the air. Moisture in the coating raises the diffusible hydrogen content of the weld and promotes hydrogen-assisted cracking in susceptible steels. Electrodes exposed to humid conditions must be redried at the temperature and time stated by the manufacturer, then kept in a heated holding oven until they are used.

Question 12Welding processes, consumables and metallurgy

Which shielding gas is the standard choice for manual gas tungsten arc welding of stainless and carbon steels?

  1. An argon–oxygen mixture
  2. Argon Correct answer.
  3. Carbon dioxide
  4. Pure nitrogen

Explanation

Argon is inert, ionises easily and gives a stable arc with good arc starting, while protecting the tungsten electrode and the molten pool from the atmosphere. Active gases such as CO2 or oxygen are used for gas metal arc welding because they react with the steel, and in GTAW they would oxidise the tungsten electrode and contaminate the weld.

Question 13Welding processes, consumables and metallurgy

In submerged arc welding, what is meant by a neutral flux?

  1. A flux with a basicity index below 0.5
  2. A flux intended only for alternating current
  3. A flux that adds no alloying elements to the weld metal Correct answer.
  4. A flux that has been fused and then reground

Explanation

A neutral flux is chemically balanced so that elements such as manganese and silicon neither increase nor decrease appreciably during welding, leaving the weld metal composition set mainly by the electrode and by dilution from the plate. Acidic fluxes tend to add manganese and silicon to the weld, while highly basic fluxes can remove them and lower oxygen content.

Question 14Welding processes, consumables and metallurgy

In the AWS flux-cored wire classification E71T-1C, what does the final letter C identify?

  1. The electrode is intended only for vertical-down welding
  2. The weld metal contains about 1% chromium
  3. The electrode has a rutile coating and runs on alternating current
  4. The electrode is used with carbon dioxide shielding gas Correct answer.

Explanation

In the AWS A5.20 system the shielding-gas designator follows the usability digit: C denotes 100% carbon dioxide shielding and M denotes a mixture of carbon dioxide and argon. The digit before it identifies welding position and current type, so E71T-1C is an all-position flux-cored wire intended for CO2 shielding.

Question 15Welding processes, consumables and metallurgy

An austenitic stainless steel weldment is held at about 600 °C for several hours during a heat treatment cycle. What is the likely result in the heat-affected zone?

  1. Chromium carbides precipitate on grain boundaries, reducing corrosion resistance Correct answer.
  2. Fine niobium carbides dissolve and the toughness improves
  3. The structure transforms entirely to ferrite and becomes more ductile
  4. Hydrogen is absorbed into the austenite and causes delayed cracking

Explanation

In the 425–870 °C range, carbon combines with chromium at the grain boundaries as chromium carbide, which locally depletes the adjacent matrix of chromium. Corrosion resistance falls and intergranular attack can follow in service. The remedy is to avoid slow cooling through that range or to use low-carbon or stabilised grades.

Question 16Welding processes, consumables and metallurgy

A welder increases the contact-tip-to-work distance during GMAW while all other settings are held constant. What is the usual result?

  1. Current falls, penetration decreases and the arc widens Correct answer.
  2. Current rises and penetration increases markedly
  3. The wire feed speed drops and the arc length shortens
  4. The shielding gas flow increases to compensate

Explanation

A longer stick-out adds resistance heating in the wire, so at a fixed voltage setting the arc current drops and the arc lengthens and spreads out. Penetration is reduced and lack of fusion at the root becomes more likely, so the nozzle-to-work distance should be kept constant during production welding.

Question 17Welding processes, consumables and metallurgy

What is the principal source of porosity when aluminium is welded by gas metal arc welding?

  1. Nitrogen absorbed from the shielding gas
  2. Carbon monoxide formed by deoxidation reactions
  3. Hydrogen from moisture or hydrocarbons on the surface Correct answer.
  4. Sulphur contamination from the filler wire

Explanation

Aluminium dissolves a large amount of hydrogen in the liquid state but almost none in the solid, so hydrogen rejected during solidification forms pores. Moisture, grease, paint, humid air and contaminated shielding gas are the usual sources, which is why thorough chemical cleaning and control of gas quality are essential before welding.

Question 18Welding processes, consumables and metallurgy

Why is a manganese-to-sulphur ratio of roughly 20:1 or higher specified for carbon steel weld metal?

  1. Manganese suppresses porosity caused by nitrogen
  2. Manganese combines with sulphur, reducing solidification cracking risk Correct answer.
  3. Manganese raises hardenability, so a high ratio avoids soft spots
  4. Manganese lowers the carbon equivalent and reduces preheat

Explanation

Sulphur forms low-melting iron sulphide films at austenite grain boundaries during solidification, and these films cannot accommodate shrinkage strain, so hot cracking occurs. Manganese has a stronger affinity for sulphur and forms high-melting manganese sulphide particles dispersed through the weld, so an adequate manganese-to-sulphur ratio greatly improves resistance to solidification cracking.

Question 19Welding processes, consumables and metallurgy

A duplex stainless steel weld is held at about 850 °C for an extended period. Which change is most damaging?

  1. Sigma phase forms and toughness and corrosion resistance fall Correct answer.
  2. Chromium nitrides precipitate and pitting resistance improves
  3. Ferrite content increases and hydrogen cracking risk rises
  4. Austenite spheroidises and the weld becomes too soft

Explanation

Duplex stainless steels form sigma, a brittle intermetallic phase, most rapidly between about 600 °C and 1000 °C, with the fastest rate near 850 °C. Sigma takes chromium and molybdenum from the surrounding phases, so impact toughness and pitting resistance drop sharply. Exposure time and interpass temperature therefore have to be controlled during welding and heat treatment.

Question 20Welding processes, consumables and metallurgy

Compared with electrode-positive operation at the same current, submerged arc welding with electrode-negative polarity normally gives:

  1. A higher electrode melt-off rate with shallower penetration Correct answer.
  2. Identical penetration but a heavier slag layer
  3. An unstable arc that is unsuitable for production work
  4. Deeper penetration and a narrower bead

Explanation

In submerged arc welding, electrode-negative polarity increases the burn-off rate of the wire for the same current, raising deposition, but it gives a shallower and wider bead than electrode-positive polarity. Electrode-positive operation is therefore chosen when deep penetration is needed, while electrode-negative operation suits high deposition, cladding and thin plate where burn-through is a risk.

Question 21Welding processes, consumables and metallurgy

In the AWS filler-metal classification ER70S-6, what does the prefix ER indicate?

  1. A bare wire intended only for submerged arc welding
  2. A covered electrode intended only for manual arc welding
  3. A flux-cored wire intended for semiautomatic welding
  4. A filler metal usable as electrode and rod Correct answer.

Explanation

In AWS filler-metal designations, the prefix ER identifies a material that may be used as a consumable electrode or as a filler rod. The rest of the classification covers strength, composition, and usability. A covered electrode would use an E prefix, while a flux-cored wire uses an E7XT format.

Question 22Welding processes, consumables and metallurgy

What is the primary function of the coating on a covered electrode used in shielded metal arc welding?

  1. To provide the granular flux layer used in submerged arc welding
  2. To shield the arc and weld pool from atmospheric contamination Correct answer.
  3. To increase the electrical conductivity of the core wire
  4. To eliminate the need for any welding current

Explanation

The coating melts and decomposes in the arc to generate shielding gas and a slag blanket. These protect the molten droplets and weld pool from oxygen and nitrogen in the air. Arc stabilization and alloying are secondary functions, not the primary reason for the coating.

Question 23Welding processes, consumables and metallurgy

Which tungsten electrode classification contains thorium oxide and is widely used for direct-current welding of carbon steel?

  1. Pure tungsten, such as EWP
  2. Ceriated tungsten, such as EWCe-2
  3. Thoriated tungsten, such as EWTh-2 Correct answer.
  4. Zirconiated tungsten, such as EWZr-8

Explanation

EWTh-2 is a thoriated tungsten electrode containing about two percent thorium oxide. Thoria improves electron emission and allows higher current-carrying capacity than pure tungsten. It is widely used for DCEN welding of carbon and stainless steels.

Question 24Welding processes, consumables and metallurgy

In submerged arc welding, what is the general effect of increasing flux basicity on weld-metal oxygen content?

  1. It lowers oxygen and usually improves toughness Correct answer.
  2. It increases oxygen content and lowers toughness
  3. It increases hydrogen content but not oxygen
  4. It has no effect on oxygen content or toughness

Explanation

Basic fluxes contain fewer acidic oxides and are more effective at lowering weld-metal oxygen. Lower oxygen generally means fewer oxide inclusions and better Charpy toughness. Acidic fluxes tend to leave higher oxygen and inclusion levels.

Question 25Welding processes, consumables and metallurgy

Which current polarity produces the deepest penetration in gas tungsten arc welding of carbon steel?

  1. Direct current electrode negative Correct answer.
  2. Alternating current with a balanced wave
  3. Direct current electrode positive
  4. Alternating current with a square wave

Explanation

In DCEN, the workpiece is the positive pole, so most of the arc energy is deposited in the joint. This produces a deep, narrow weld and reduces heat load on the tungsten electrode. DCEP reverses this and gives shallow penetration.

Question 26Welding processes, consumables and metallurgy

Which mechanism is primarily responsible for reheat cracking in the coarse-grained heat-affected zone of Cr-Mo low-alloy steel weldments during post-weld heat treatment?

  1. Lamellar tearing caused by through-thickness strain
  2. Solidification shrinkage at the weld centerline
  3. Creep strain in a hardened coarse-grained HAZ Correct answer.
  4. Hydrogen diffusion into the weld metal

Explanation

During post-weld heat treatment, residual stresses relax by creep, and the coarse-grained HAZ may have insufficient ductility to accommodate that strain. Intergranular reheat cracking can then develop in Cr-Mo and other low-alloy steels. The problem is related to high-temperature stress relaxation, not to hydrogen or solidification.

Question 27Welding processes, consumables and metallurgy

In the AWS flux-cored electrode classification E71T-1, what does the digit 1 immediately after the T designate?

  1. The electrode is classified for flat and horizontal positions only
  2. The electrode contains 1% nickel
  3. The electrode is classified for all-position welding Correct answer.
  4. The electrode is limited to single-pass welding

Explanation

The digit after T in an E71T-1 classification is a usability designation. For T-1, it identifies an all-position flux-cored electrode. It is not a strength, composition, or pass-number value.

Question 28Welding processes, consumables and metallurgy

Which microstructural feature is most characteristic of 475 °C embrittlement in ferritic stainless steel weldments?

  1. Sensitization by chromium carbide
  2. Sigma phase
  3. Chromium-rich alpha-prime phase Correct answer.
  4. Martensite formation

Explanation

Ferritic stainless steels exposed around 475 °C can form very fine chromium-rich alpha-prime precipitates within the ferrite. This hardening reduces toughness and is known as 475 °C embrittlement. Sigma phase and carbide sensitization occur in different temperature ranges.

Question 29Welding processes, consumables and metallurgy

In GMAW, what is the immediate effect of increasing arc voltage while wire-feed speed and travel speed remain constant?

  1. Wire-feed speed automatically decreases
  2. Arc length increases and the bead widens Correct answer.
  3. Arc length decreases and penetration becomes deeper
  4. The shielding gas flow rate increases

Explanation

Arc voltage is the main control of arc length in GMAW. Raising voltage lengthens the arc and spreads the arc force, which widens and flattens the bead. Penetration usually becomes shallower rather than deeper.

Question 30Welding processes, consumables and metallurgy

Which shielding gas mixture is most suitable for spray-transfer GMAW of carbon steel?

  1. 100% carbon dioxide
  2. 75% argon/25% carbon dioxide
  3. 98% argon/2% oxygen Correct answer.
  4. 100% helium

Explanation

Spray transfer needs an argon-rich shielding gas so the arc remains stable and the metal transfers as fine droplets. A small addition of oxygen, such as two percent, improves arc stability and weld wetting. Carbon-dioxide-rich mixtures do not support true spray transfer.

Question 31Welding processes, consumables and metallurgy

Which stainless steel family is hardened mainly by a martensitic transformation during cooling of the weld?

  1. Duplex stainless steels
  2. Austenitic stainless steels
  3. Ferritic stainless steels
  4. Martensitic stainless steels Correct answer.

Explanation

Martensitic grades contain enough carbon and chromium to transform from austenite to martensite when cooled, so they harden in the weld and heat-affected zone. Austenitic and ferritic grades do not harden by this mechanism, and duplex grades rely on a ferrite-austenite balance.

Question 32Welding processes, consumables and metallurgy

Which welding current is normally selected for manual gas tungsten arc welding of aluminium alloys?

  1. Alternating current Correct answer.
  2. Direct current, electrode negative
  3. Direct current, electrode positive
  4. Pulsed direct current, electrode negative

Explanation

Alternating current alternates between electrode-negative and electrode-positive half-cycles. The positive half-cycle helps break up the refractory aluminium oxide, while the negative half-cycle provides penetration and limits tungsten erosion.

Question 33Welding processes, consumables and metallurgy

A foundry preheats a 0.5% carbon steel casting to about 250 °C before welding. What is the main reason for this preheat?

  1. To increase the current capacity of the electrode
  2. To eliminate the need for post-weld heat treatment
  3. To slow the cooling rate and reduce hardening and cracking Correct answer.
  4. To remove hydrogen from the electrode coating

Explanation

Preheating raises the base metal temperature so the weld and heat-affected zone cool more slowly. This reduces the chance of forming hard martensite and gives hydrogen time to escape, lowering cracking risk. It does not replace controlled post-weld heat treatment where that is specified.

Question 34Welding processes, consumables and metallurgy

Which condition most promotes solidification cracking in austenitic stainless steel weld metal?

  1. A high welding heat input with slow solidification
  2. A fully austenitic weld microstructure with little ferrite Correct answer.
  3. A high delta-ferrite content in the weld metal
  4. Low sulphur and phosphorus levels in the base metal

Explanation

Solidification cracking occurs when low-melting films remain along solidifying grain boundaries and contraction strains pull them apart. A small amount of delta ferrite improves resistance by changing the solidification mode and helping dissolve sulphur and phosphorus. Fully austenitic weld metal is therefore more crack-sensitive.

Question 35Welding processes, consumables and metallurgy

What is the principal cause of lamellar tearing in welded steel fabrications?

  1. Hydrogen diffusing into the weld heat-affected zone
  2. Through-thickness tensile strain in plate containing flattened non-metallic inclusions Correct answer.
  3. Excessive grain growth from a high welding heat input
  4. Chloride attack at the weld toe

Explanation

Lamellar tearing occurs when restrained joints impose tensile strain through the plate thickness. Non-metallic inclusions, flattened during rolling, provide weak planes that decohere and link up. Good joint design and lower-restraint details reduce the risk.

Question 36Welding processes, consumables and metallurgy

In self-shielded flux-cored arc welding, what provides the shielding atmosphere around the arc?

  1. A vacuum chamber surrounding the joint
  2. Vapours generated by ingredients in the flux core Correct answer.
  3. A blanket of granular flux poured ahead of the arc
  4. A separate argon-rich gas supplied through the torch

Explanation

Self-shielded flux-cored wires contain ingredients that decompose or vaporise in the arc to form a protective gas shield. No external shielding gas is supplied, so the process is used where wind or access makes gas shielding difficult.

Question 37Welding processes, consumables and metallurgy

For carbon and carbon-manganese steels, which carbon equivalent value is commonly used as a practical threshold above which preheat should be considered?

  1. 0.20
  2. 0.30
  3. 0.40 Correct answer.
  4. 0.60

Explanation

A carbon equivalent of about 0.40 is widely used as a threshold for carbon-manganese steels. Above this value, hardenability increases and preheat and controlled heat input become important, although thickness and hydrogen level must also be considered.

Question 38Welding processes, consumables and metallurgy

Why is nitrogen often added to the argon shielding gas when welding duplex stainless steel?

  1. It helps restore austenite and balance the ferrite content Correct answer.
  2. It prevents porosity by scavenging oxygen
  3. It raises the heat input and slows cooling
  4. It increases the ferrite content of the weld metal

Explanation

Duplex stainless steels need a balanced ferrite-austenite microstructure for toughness and corrosion resistance. Nitrogen is a strong austenite former and can compensate for nitrogen lost from the weld pool, helping to restore austenite and avoid excessive ferrite.

Question 39Welding processes, consumables and metallurgy

What is the accepted mechanism for knife-line attack in a stabilised austenitic stainless steel weldment?

  1. Chloride ions penetrating slag inclusions at the weld toe
  2. Chromium carbide precipitation in a narrow band beside the fusion line Correct answer.
  3. Hydrogen collecting along the fusion boundary during welding
  4. Sigma phase forming throughout the weld metal during rapid cooling

Explanation

Knife-line attack occurs in stabilised grades when the stabilising carbides dissolve at high temperature and carbon remains in solution. On subsequent heating or cooling, chromium carbides precipitate in a narrow band close to the fusion line where there is insufficient stabiliser. This narrow corroded band resembles a knife line.

Question 40Welding processes, consumables and metallurgy

Why is a maximum interpass temperature specified when welding quenched-and-tempered high-strength steel?

  1. To increase the deposition rate of the electrode
  2. To ensure complete fusion between passes
  3. To prevent nitrogen pickup in the weld pool
  4. To avoid softening and loss of strength in the heat-affected zone Correct answer.

Explanation

Quenched-and-tempered steels obtain strength from a controlled heat treatment. Excessive interpass temperature can over-temper the heat-affected zone, reducing hardness and strength. A maximum interpass temperature therefore protects the properties of the finished joint.

Question 41Codes, standards and specification requirements

Which Canadian standard establishes the certification requirements for companies performing fusion welding of steel structures?

  1. CSA W59
  2. CSA W178.1
  3. CSA W47.1 Correct answer.
  4. CSA W48

Explanation

CSA W47.1 is the Canadian certification standard for companies performing fusion welding of steel structures. It sets requirements for welding supervisors, welders, procedures, and quality control. CSA W59 is the companion fabrication code, while W48 and W178.1 address filler metals and inspection organizations.

Question 42Codes, standards and specification requirements

Which standard is the companion construction code that supplies welding requirements for steel structures built by a CSA W47.1-certified fabricator?

  1. CSA W47.2
  2. CSA B51
  3. CSA W59 Correct answer.
  4. CSA W178.2

Explanation

CSA W59 is the construction code for welded steel structures and is commonly invoked alongside CSA W47.1 certification. W47.1 certifies the company's welding capability, while W59 supplies design, fabrication, and inspection rules. W47.2 applies to aluminum, and W178.2 covers inspector certification.

Question 43Codes, standards and specification requirements

Under CSA W178.2, which level of welding inspector holds the highest qualification and may supervise other inspectors and interpret code requirements?

  1. Level 1
  2. Level 3 Correct answer.
  3. Level 2
  4. Trainee

Explanation

CSA W178.2 establishes three certification levels for welding inspectors. Level 3 is the highest and may perform or supervise all inspection tasks and interpret code requirements. Levels 1 and 2 have progressively limited scopes of work.

Question 44Codes, standards and specification requirements

A fabricator intends to use a prequalified joint detail from CSA W59. Which condition must be satisfied before the joint can be welded without procedure qualification testing?

  1. The joint is inspected by a Level 3 inspector before welding begins
  2. Joint details and parameters fall within W59 prequalified limits Correct answer.
  3. The welder has passed a 6G pipe test administered by the CWB
  4. A separate PQR is tested for every production joint and approved by the engineer

Explanation

CSA W59 permits prequalified joint details to be used without procedure qualification testing only when the base metal, filler metal, joint geometry, and welding parameters remain within the limits stated in the standard. Any departure from those limits requires qualification by testing.

Question 45Codes, standards and specification requirements

A qualified WPS specifies gas metal arc welding. The fabricator switches to flux-cored arc welding while keeping the same base metal and joint detail. Under CSA W47.1, what is the correct action?

  1. Revise the WPS without testing because the base metal and joint are unchanged
  2. Take no action provided the measured heat input remains within the original range
  3. Requalify only the welders, since the process change affects technique rather than procedure
  4. Requalify the WPS with a new PQR because the process change is essential Correct answer.

Explanation

A change in welding process is an essential variable under CSA W47.1, so the existing WPS no longer covers the work. The fabricator must prepare a new PQR by testing the FCAW process and then issue a revised WPS. Requalifying welders alone does not address procedure qualification.

Question 46Codes, standards and specification requirements

A CWB-certified Division 1 fabricator awards part of a CSA W47.1 steel project to another welding shop. What is required?

  1. Only the subcontractor's welders require qualification; the shop itself need not be certified
  2. The subcontractor may weld under the prime fabricator's WPS without certification if inspection is increased
  3. The subcontractor must hold its own valid CWB certification for the work Correct answer.
  4. The prime fabricator's certification automatically extends to the subcontractor's shop

Explanation

CSA W47.1 certification is granted to a specific company and does not automatically extend to another shop. A subcontractor performing fusion welding of steel structures must hold its own valid certification for the applicable division and scope. The prime fabricator remains responsible for ensuring the subcontractor's compliance.

Question 47Codes, standards and specification requirements

Under CSA W47.1, what is a primary responsibility of the welding supervisor?

  1. Approving the engineer's design calculations and drawing revisions
  2. Ensuring welding follows qualified WPSs and that welders are qualified Correct answer.
  3. Certifying the company's financial records for the CWB annual audit
  4. Personally performing all radiographic testing required by the project specification

Explanation

The welding supervisor is responsible for controlling production welding, including adherence to qualified WPSs and verification that welders hold valid qualifications for the work. Radiographic testing, financial auditing, and design approval are outside that role.

Question 48Codes, standards and specification requirements

In CSA W48, what is the primary basis for classifying a covered electrode such as E4918?

  1. Minimum tensile strength, welding position, and coating or current type Correct answer.
  2. Base metal thickness, preheat temperature, and interpass temperature
  3. Electrode diameter, packaging quantity, and lot certification number
  4. Welder qualification position, joint type, and travel speed range

Explanation

CSA W48 classifies covered electrodes by minimum tensile strength, welding position, and coating or current type, along with other suffix details. The E4918 designation identifies a low-hydrogen electrode with approximately 490 MPa minimum tensile strength, usable in all positions.

Question 49Codes, standards and specification requirements

Under ASME BPVC Section IX, a manufacturer changes the shielding gas for a gas metal arc welding procedure from a 75% argon/25% carbon dioxide mixture to pure carbon dioxide. What is required?

  1. Only welder performance qualification is affected by the gas change
  2. A new procedure qualification is required because shielding gas composition is essential Correct answer.
  3. Only a WPS revision is required because the filler metal classification is unchanged
  4. No action is required because the base metal and joint design are unchanged

Explanation

Under ASME BPVC Section IX, shielding gas composition is an essential variable for gas metal arc welding. Changing from a mixed argon-carbon dioxide gas to pure carbon dioxide alters arc characteristics and weld properties, so a new PQR is required before the WPS can be revised.

Question 50Codes, standards and specification requirements

A project specification invokes CSA W59 and also requires 100% radiographic testing of all complete-joint-penetration groove welds. The fabricator argues that W59 does not require this testing. How should the inspector resolve the conflict?

  1. The inspector may choose either requirement, provided the choice is documented
  2. The code minimum always overrides a project specification unless the owner waives it
  3. The specification clause is invalid because W59 prohibits additional radiographic testing
  4. The specification governs because it is stricter than the code minimum Correct answer.

Explanation

Codes such as CSA W59 set minimum requirements, and a project specification may impose stricter requirements without conflicting with the code. When the specification calls for additional radiographic testing, the inspector should enforce the more stringent contractual requirement. The code does not prohibit supplementary testing.