API 577 Welding Inspection and Metallurgy

Which welding process uses a consumable, flux-coated electrode and is commonly called stick welding in refinery fabrication?

• AGas tungsten arc welding (GTAW)
• BShielded metal arc welding (SMAW)
• CSubmerged arc welding (SAW)
• DGas metal arc welding (GMAW)

In GTAW, which electrode material is used and is generally alloyed with oxides such as thoria, ceria or lanthana to improve arc starting?

• ACopper
• BGraphite
• CTungsten
• DMolybdenum

Which GMAW metal transfer mode produces the lowest heat input and is preferred for thin sections and out-of-position welding?

• ASpray transfer
• BGlobular transfer
• CShort-circuiting transfer
• DPulsed spray transfer

Which statement about submerged arc welding (SAW) per API RP 577 is correct?

• AThe arc is visible so the welder can observe the puddle directly
• BFlux shields the arc and molten pool from the atmosphere
• CSAW is primarily an out-of-position process for vertical welds
• DSAW cannot be used for carbon steel pressure vessels

The acronym FCAW stands for which welding process?

• AFlux cored arc welding
• BFlash carbon arc welding
• CForge cold-arc welding
• DFused ceramic arc welding

Which current type and polarity is most commonly used for SMAW with E7018 electrodes?

• ADCEN (straight polarity)
• BDCEP (reverse polarity)
• CAC low frequency only
• DDC pulsed at 50 Hz

Plasma arc welding (PAW) differs from GTAW primarily because PAW:

• AUses a consumable electrode fed through the torch
• BConstricts the arc through a water-cooled copper orifice
• CUses carbon dioxide as the shielding gas
• DOperates only on AC square-wave current

Which of the following is a primary advantage of GTAW over SMAW for root passes on stainless steel process piping?

• AHigher deposition rates
• BGreater tolerance to wind
• CBetter control of heat input and weld quality
• DElimination of the need for shielding gas

Which GMAW shielding gas mixture is typical for spray transfer on carbon steel?

• A100% CO2
• B75% argon / 25% CO2 or higher argon content
• C100% helium
• D80% nitrogen / 20% oxygen

In SAW, the flux can be described by its behavior with respect to alloy pickup. A neutral flux is one that:

• AAdds significant silicon and manganese to the weld
• BProduces no significant change in weld metal composition across voltage changes
• CRemoves all alloying elements from the weld metal
• DCan only be used with nickel-based alloys

Which welding process is commonly used for attaching studs and insulation pins to pressure vessels and tank walls?

• AOxyfuel welding (OFW)
• BStud arc welding (SW)
• CElectroslag welding (ESW)
• DFriction stir welding (FSW)

During GTAW of austenitic stainless steel, an argon purge is typically used on the root side of the weld to prevent:

• AHeat-affected zone softening
• BSugaring and severe root oxidation
• CSpatter buildup inside the pipe
• DLoss of molybdenum from the filler metal

Which welding process would you expect to have the highest deposition rate on a long horizontal seam of a heavy-wall carbon steel pressure vessel?

• ASMAW
• BGTAW
• CSAW
• DGMAW short-circuit transfer

Which statement about GMAW metal-cored electrodes is correct?

• AThey contain flux similar to FCAW electrodes
• BThey contain metal powders to improve deposition and efficiency
• CThey require no external shielding gas
• DThey are classified under AWS A5.5 as low-hydrogen electrodes

Which welding process variable is most directly controlled by the electrical stickout (contact-tip-to-work distance) in GMAW and FCAW?

• AShielding gas composition
• BWire feed speed setting
• CWelding current (for a fixed wire feed speed)
• DBase metal P-Number

Per ASME Section IX, the document that records the actual variables used to produce a test coupon and the resulting mechanical test results is called the:

• AWelding procedure specification (WPS)
• BProcedure qualification record (PQR)
• CWelder performance qualification (WPQ)
• DMaterial test report (MTR)

Per ASME Section IX QW-401.1, a change in an essential variable requires which action?

• ARe-qualification of the WPS via a new PQR
• BNotification to the Jurisdiction only
• CA new material test report
• DA change to the welder continuity log only

Which of the following is classified by ASME Section IX as an essential variable for SMAW per QW-253?

• ATravel speed
• BA change in P-Number of the base metal
• CType of flux shielding
• DDirection of welding progression (uphill vs downhill) for non-impact work

A welder qualifies on a 1/2-inch thick groove weld test coupon using SMAW. Per ASME Section IX QW-452.1(b), what is the maximum base-metal thickness the welder is qualified to weld in production?

• A1/2 inch
• B3/4 inch
• C1 inch
• DMaximum to be welded

Per ASME Section IX QW-422, the P-Number grouping is assigned to base metals primarily to:

• AReduce the number of procedure qualifications required
• BDefine the maximum allowable design stress
• CSet the purchase price of the material
• DControl the carbon content of filler wire

Per ASME Section IX QW-423, which of the following is an example of a permitted base metal substitution for procedure qualification?

• AA weld made on one P-Number qualifies welding of any P-Number
• BA PQR on P-No. 1 qualifies production welding of P-No. 8 austenitic stainless steel
• CA PQR on a higher group in the same P-Number can qualify welding of the lower group
• DAny P-No. 5A PQR qualifies nickel alloy P-No. 43 welding

Per ASME Section IX QW-200.4, a welder who successfully welds a groove weld coupon in the 6G position is qualified for which production welding positions?

• AOnly 6G
• B1G and 2G only
• CAll groove positions, including 5G and 6G
• DOnly fillet welds

Per ASME Section IX QW-322, a welder's qualification is considered to remain in effect as long as the welder performs welding on any process within what maximum time period?

• A30 days
• B3 months
• C6 months
• D12 months

Per ASME Section IX QW-202, how many mechanical tests are typically required on a groove weld procedure qualification coupon of 3/4-inch thickness without impact testing?

• ATwo tension and two guided bend tests (four total)
• BOne tension test only
• CThree tension and three radiographs
• DFive impact tests

Per ASME Section IX QW-153, a reduced-section tension test specimen is acceptable if the ultimate tensile strength is:

• AExactly equal to the base metal specified minimum
• BNot less than the specified minimum tensile of the base metal
• CAt least 10% above the base metal specified minimum
• DNot less than the filler metal all-weld-metal value

Per ASME Section IX QW-160, guided bend tests are acceptable if the weld and HAZ show:

• ANo open defects exceeding 1/8 inch after bending
• BNo open defects exceeding 3 mm when any dimension is a fracture
• CNo open discontinuities exceeding 1/8 inch in any direction after the bend (with minor co…
• DA full ductile fracture across the specimen

A WPS for SMAW must address which of the following items at a minimum?

• AOnly the base metal P-Number
• BOnly the filler metal F-Number
• CAll essential and nonessential variables listed in QW-253
• DOnly the preheat temperature

Per ASME Section IX, when the impact testing (notch toughness) is a requirement, which type of variable must additionally be addressed on the WPS?

• ANonessential variables only
• BSupplementary essential variables
• COptional variables
• DRecord-only variables

Per ASME Section IX QW-403.8, a change in base metal thickness beyond the qualified range is considered which type of variable for procedure qualification of SMAW?

• ANonessential
• BEssential
• CSupplementary essential
• DNot addressed

A welder qualified in GMAW short-circuit transfer mode on carbon steel wishes to weld production welds using spray transfer. Per ASME Section IX QW-404.32, what is the status of this change?

• ANo action needed; same process
• BRe-qualification is required because mode of metal transfer is an essential variable for…
• COnly a PQR update is needed
• DOnly the WPS needs revision

Per ASME Section IX QW-432, two filler metals are assigned to the same F-Number when they:

• AHave identical chemical compositions
• BHave the same nominal tensile strength
• CHave essentially the same usability characteristics (out-of-position capability, arc char…
• DAre produced by the same manufacturer

Per ASME Section IX QW-442, A-Numbers are assigned based on:

• AThe chemical composition of the deposited weld metal
• BThe usability characteristics of the electrode
• CThe physical shape of the filler product
• DThe diameter of the filler wire

Per API RP 577 Section 7 and AWS A5.1, in the SMAW electrode classification E7018, what does the 70 represent?

• APercent elongation
• BMinimum tensile strength in ksi
• CBead profile code
• DYield strength in ksi

Per API RP 577 Section 7, what does the 1 in the classification E7018 indicate?

• AAll welding positions
• BFlat position only
• CHorizontal position only
• DVertical down only

Why are low-hydrogen SMAW electrodes such as E7018 stored in heated ovens when not in use?

• ATo improve arc starting
• BTo prevent moisture absorption in the flux, which can lead to hydrogen-induced cracking
• CTo make the electrodes stick to the holder better
• DTo reduce slag formation

Per API RP 577 Section 7, what is the typical holding oven temperature range for low-hydrogen SMAW electrodes after they are removed from their hermetic container?

• A100-150 degrees F
• B225-300 degrees F
• C500-600 degrees F
• D800-900 degrees F

The AWS filler metal specification for carbon steel electrodes used in SMAW is:

• AAWS A5.1
• BAWS A5.4
• CAWS A5.18
• DAWS A5.20

Which backing gas is commonly used to purge the root side of austenitic stainless steel pipe welds?

• AOxygen
• BArgon
• CCarbon dioxide
• DHydrogen

Per API RP 577 Section 10, the hardness of martensite in steel is primarily a function of:

• ANickel content
• BCarbon content
• CCopper content
• DVanadium content

In a fusion weld on carbon steel, the zone adjacent to the fusion line that does not melt but is metallurgically altered by the welding heat is called:

• AThe base metal
• BThe weld metal
• CThe heat-affected zone (HAZ)
• DThe fusion boundary

Per API RP 577 Section 10, which four conditions must all be present for hydrogen-induced cracking (HIC) to occur in a steel weld?

• AHydrogen, susceptible microstructure, tensile stress, and temperature below about 400 deg…
• BHydrogen, stainless steel, compressive stress, and 1200 degrees F
• CHydrogen, cast iron, creep loading, and humidity
• DHydrogen, tool steel, lack of penetration, and copper filler

Per API RP 577 Section 10, preheat for carbon steel prior to welding is applied primarily to:

• AIncrease deposition rate
• BSlow cooling to reduce HAZ hardness and promote hydrogen diffusion
• CEliminate slag inclusions
• DImprove X-ray contrast for RT

Which of the following best describes postweld heat treatment (PWHT) for P-No. 1 carbon steel?

• AHolding at 400 degrees F for 15 minutes
• BHolding at approximately 1100-1200 degrees F for 1 hour per inch of nominal thickness
• CHolding at 1800 degrees F for 8 hours
• DQuench and tempering at ambient temperature

Per API RP 577 Section 10, sensitization of austenitic stainless steel occurs when:

• AThe steel is over-aged at 1800 degrees F
• BChromium carbides precipitate at grain boundaries between about 800 and 1500 degrees F
• CNickel migrates out of the surface at room temperature
• DThe steel is cold worked below 32 degrees F

Per API RP 577 Section 10, which element is the most common primary alloying element used to prevent sensitization in grades such as 347 stainless?

• ATitanium
• BAluminum
• CNiobium (also called columbium)
• DTungsten

Per API RP 577 Section 10, the carbon equivalent (CE) formula is used to estimate:

• ATensile strength
• BWeldability and preheat requirements
• CThermal conductivity
• DDensity

A refinery feed heater inlet pipe showing evidence of rapid HAZ softening during service is likely experiencing which creep-related phenomenon common to CSEF steels such as Grade 91?

• AType IV creep cracking
• BChloride stress corrosion cracking
• CSulfidation
• DHigh-temperature hydrogen attack