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API 577 practice questions

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Question 1Welding inspection and quality assurance

What is the primary purpose of a welding procedure specification (WPS)?

  1. Qualified parameters and technique for making the weld Correct answer.
  2. A list of non-destructive examination results for production welds
  3. A record of the actual variables used during procedure qualification
  4. A certificate of the individual welder's skill for a joint configuration

Explanation

The WPS is the written instruction that gives the welder the qualified ranges for process, filler, current, preheat, and technique. The PQR records the actual variables and results from the qualification test, while the WPQ tests the welder. Production NDE results are recorded separately.

Question 2Welding inspection and quality assurance

A procedure qualification record (PQR) primarily documents which of the following?

  1. The production weld schedule agreed with the client
  2. The calibration status of the inspection gauges
  3. The welder's employment history and previous qualifications
  4. The actual variables and test results used to qualify a WPS Correct answer.

Explanation

The PQR is the record of the actual welding variables used for the qualification test and the results of mechanical or other testing. It supports the WPS and is retained as objective evidence. It is not a welder qualification or a production schedule.

Question 3Welding inspection and quality assurance

In an inspection and test plan (ITP), what is a hold point?

  1. An optional attendance point the inspector may waive at discretion
  2. A notification point where the fabricator reports progress after covering work
  3. A release document that authorizes shipment of finished welds
  4. A stage where work stops until the designated inspection is accepted Correct answer.

Explanation

A hold point stops the work from advancing until the designated inspection or approval has been completed and accepted. It protects a characteristic that cannot be verified later. A witness point, by contrast, does not normally stop work.

Question 4Welding inspection and quality assurance

Which examination method is best suited for detecting surface-breaking discontinuities in an austenitic stainless steel weld?

  1. Radiographic testing
  2. Penetrant testing Correct answer.
  3. Magnetic particle testing
  4. Ultrasonic testing

Explanation

Austenitic stainless steel is nonmagnetic, so magnetic particle testing cannot be used effectively. Penetrant testing detects surface-breaking discontinuities by capillary action and is suitable for nonmagnetic materials. Radiography and ultrasonics are used mainly for internal or volumetric conditions.

Question 5Welding inspection and quality assurance

What is a primary purpose of applying preheat before welding a thick carbon steel joint?

  1. To improve the appearance of the finished weld cap
  2. To increase the current capacity of the power source
  3. To slow cooling and reduce hydrogen cracking risk Correct answer.
  4. To eliminate the need for post-weld heat treatment

Explanation

Preheat raises the base metal temperature so the weld cools more slowly, which helps hydrogen escape and lowers the risk of hydrogen-assisted cracking. It also reduces thermal gradients and shrinkage stresses. Preheat does not replace PWHT where PWHT is required.

Question 6Welding inspection and quality assurance

How is arc heat input calculated for a welding operation?

  1. Travel speed times efficiency divided by current
  2. Voltage divided by current times number of passes
  3. Current times voltage divided by electrode diameter
  4. Voltage × current × travel time per unit length Correct answer.

Explanation

Heat input is calculated as voltage multiplied by current multiplied by 60 divided by travel speed, using consistent units. For example, volts × amps × 60 / (inches per minute) gives joules per inch. Electrode diameter and number of passes are not direct terms in the basic formula.

Question 7Welding inspection and quality assurance

What does a welder performance qualification (WPQ) demonstrate?

  1. That the welding machine is calibrated to the specified output
  2. That the base metal and filler metal are compatible
  3. That the welding procedure produces the required mechanical properties
  4. That the welder can produce a sound weld with a qualified procedure Correct answer.

Explanation

A WPQ tests the individual welder's ability to make a sound weld using a qualified welding procedure for a given process, position, and joint type. It does not qualify the procedure itself or establish base metal and filler metal compatibility. Machine calibration is controlled by a separate quality process.

Question 8Welding inspection and quality assurance

Why are low-hydrogen covered electrodes stored in heated holding ovens after opening?

  1. To soften the coating so the electrode can bend easily
  2. To increase the deposition rate during welding
  3. To keep the coating dry and limit hydrogen pickup Correct answer.
  4. To prevent the electrode from becoming magnetized

Explanation

Low-hydrogen electrodes absorb moisture from the air after opening, and moisture introduces hydrogen into the weld. Heated holding ovens keep the coating dry and help preserve low-hydrogen condition. Electrodes that exceed exposure limits are normally rebaked or discarded according to the manufacturer's instructions.

Question 9Welding inspection and quality assurance

A production weld requires a change from the qualified WPS: the current is increased beyond the qualified range. What is the correct quality assurance action?

  1. Requalify the WPS or use another qualified WPS Correct answer.
  2. Obtain verbal approval from the welder before continuing
  3. Record the change on the PQR and continue without further qualification
  4. Proceed because any change within the same process is acceptable

Explanation

Current range is an essential variable for most welding procedures because it affects heat input, penetration, and mechanical properties. Exceeding the qualified range requires requalification or use of another WPS that covers the proposed parameters. The PQR cannot simply be edited to match production changes.

Question 10Welding inspection and quality assurance

When welding austenitic stainless steel for corrosion service, why is interpass temperature usually limited?

  1. To keep the weld metal from becoming ferromagnetic
  2. To prevent the weld from cooling faster than the base metal
  3. To reduce sensitization and loss of corrosion resistance Correct answer.
  4. To maintain the electrode coating at the correct moisture level

Explanation

Excessive interpass temperature can promote chromium carbide precipitation and other metallurgical changes that reduce corrosion resistance in austenitic stainless steel. Limiting interpass temperature also helps control distortion and toughness. Moisture control for electrodes is a separate consumable issue.

Question 11Welding inspection and quality assurance

What is the main reason for post-weld heat treatment (PWHT) of a thick carbon steel pressure vessel weld?

  1. To remove all residual stresses completely from the joint
  2. To increase the hardness of the heat-affected zone
  3. To allow the weld to be examined by magnetic particle testing
  4. To reduce residual stresses and temper the heat-affected zone Correct answer.

Explanation

PWHT reduces residual welding stresses and tempers hard heat-affected zone microstructures, which lowers the risk of cracking and improves toughness. It does not remove every residual stress. Increasing hardness would generally be undesirable.

Question 12Welding inspection and quality assurance

For a hardenable carbon steel weld, why is delayed inspection sometimes specified 24 to 48 hours after welding?

  1. Hydrogen-assisted cracks may form only after a delay Correct answer.
  2. Radiographic film sensitivity improves with time
  3. The base metal cools to ambient temperature only after two days
  4. The weld surface becomes smoother and easier to inspect

Explanation

Hydrogen introduced during welding can diffuse and concentrate in hard heat-affected zones, causing cracking hours after the weld is completed. Delayed examination allows time for these cracks to form so they are not missed. Cooling to ambient temperature usually occurs much sooner than two days.

Question 13Welding inspection and quality assurance

A production weld is found with undercut exceeding the acceptance limit. Which of the following is a proper nonconformance disposition?

  1. Repair the weld, re-examine it, and document the repair Correct answer.
  2. Discard the report and re-examine a different area
  3. Paint over the undercut and release the weld for service
  4. Change the acceptance limit to match the measured undercut

Explanation

A nonconformance must be dispositioned by an authorized method such as repair, rework, use-as-is by engineering evaluation, or rejection. Repair welds are then re-examined to the original acceptance criteria and documented. Changing the acceptance limit or hiding the finding is not a valid disposition.

Question 14Welding inspection and quality assurance

An inspector finds the root gap during fit-up is larger than the WPS allows. What is the most appropriate action?

  1. Allow the welder to close the gap by using a larger electrode
  2. Stop the fit-up and correct the root gap before welding Correct answer.
  3. Continue and increase the weld volume to fill the gap
  4. Record the gap and accept it if the cap is ground flush

Explanation

Joint fit-up dimensions are part of the qualified welding procedure and affect penetration, dilution, and distortion. A root gap outside the qualified range must be corrected before welding or addressed through an approved deviation. Increasing weld volume or using a larger electrode does not restore procedure qualification.

Question 15Welding inspection and quality assurance

A torque wrench used for final bolting has been found out of calibration for the past month. What is the main quality assurance concern?

  1. Future bolting must be done without a torque wrench
  2. Joints made during that period may not meet the specified torque Correct answer.
  3. The calibration laboratory must be replaced immediately without delay
  4. The wrench must be repainted to show its new status

Explanation

Calibration provides confidence that measurements are accurate and traceable. If a torque wrench is out of tolerance, the adequacy of joints assembled during the affected period is uncertain and must be evaluated. Repainting or blaming the laboratory does not address the affected product.

Question 16Welding inspection and quality assurance

On a radiograph, a cluster of small, dark, rounded indications scattered through the weld most likely represents what?

  1. Transverse cracks
  2. Slag inclusions
  3. Lack of fusion
  4. Gas porosity Correct answer.

Explanation

Gas porosity appears on a radiograph as dark, rounded indications because gas voids absorb less radiation than the surrounding metal. Slag inclusions are usually irregular and darker but elongated, while lack of fusion and cracks appear as sharp linear indications. The rounded shape and scattered distribution point to porosity.

Question 17Welding inspection and quality assurance

Which examination method is normally used to detect laminations in a steel plate before fabrication?

  1. Ultrasonic testing Correct answer.
  2. Magnetic particle testing
  3. Visual testing
  4. Penetrant testing

Explanation

Laminations are internal planar discontinuities parallel to the plate surface, so ultrasonic testing is used to detect them before fabrication. Penetrant and magnetic particle testing are sensitive mainly to surface or near-surface conditions. Visual testing cannot reveal internal laminations.

Question 18Welding inspection and quality assurance

How does a witness point differ from a hold point in an inspection and test plan?

  1. A witness point is used only for supplier audits
  2. A witness point always stops production until the inspector signs
  3. Notice is given, but work continues if the inspector is absent Correct answer.
  4. A witness point applies only to final hydrostatic testing

Explanation

A hold point stops work until the required inspection is completed and accepted. A witness point requires notification so the inspector may attend, but it normally does not stop work if the inspector does not attend. Both are planning controls in the ITP.

Question 19Welding inspection and quality assurance

A weld repair is being planned. Which document should define the repair procedure and any required re-examination?

  1. The welder's personnel file
  2. An approved repair procedure with the inspection plan Correct answer.
  3. The shipping release note
  4. The purchase order and mill certificate for the base metal

Explanation

Repairs must follow an approved repair procedure or a qualified WPS, and the inspection plan should define the re-examination requirements. Repair records are retained as part of the quality documentation. Personnel files and shipping documents do not define repair controls.

Question 20Welding inspection and quality assurance

Why is filler metal lot traceability important in a welding quality program?

  1. It proves that the welder has been paid for the work
  2. It replaces the need for a WPS in routine production
  3. It permits investigation and recall if a lot is defective Correct answer.
  4. It allows the filler metal to be reused after moisture exposure

Explanation

Lot traceability links consumables to the welds where they were used, so a defective or nonconforming lot can be investigated and affected welds identified. It does not permit reuse of moisture-damaged electrodes or replace the WPS. Traceability is a key element of quality records.

Question 21Welding inspection and quality assurance

During PWHT of a vessel, thermocouples are placed on the weld and adjacent base metal. What is the main reason for this placement?

  1. To check that the welding machine is properly grounded
  2. To determine the welding current used for the root pass
  3. To confirm the required temperature across weld and HAZ Correct answer.
  4. To measure the cooling rate of the vessel after the hydrotest

Explanation

Thermocouples on the weld and adjacent base metal show whether the required PWHT temperature is reached across the weld and heat-affected zone. Placement should represent the hottest and coldest locations of the component. They are not used to set welding current or verify grounding.

Question 22Welding inspection and quality assurance

A weld is made at 200 A, 25 V, and 150 mm/min travel speed. What is the approximate heat input in kJ/mm?

  1. 2.0 kJ/mm Correct answer.
  2. 3.3 kJ/mm
  3. 0.33 kJ/mm
  4. 20 kJ/mm

Explanation

Heat input equals voltage × current × 60 divided by travel speed in mm/min, then divided by 1000 to convert joules to kilojoules. Here, 25 × 200 × 60 / 150 = 2000 J/mm, which is 2.0 kJ/mm. The other values result from arithmetic or unit errors.

Question 23Welding inspection and quality assurance

A WPS qualified without PWHT is to be used on production that requires PWHT. What is the quality assurance consequence?

  1. The WPS can be used if the welder is qualified in 6G
  2. The PQR can be amended with PWHT results from another test
  3. The procedure must be qualified with PWHT as essential Correct answer.
  4. No action is needed because PWHT only relieves stress

Explanation

Post-weld heat treatment changes microstructure and mechanical properties, so it is an essential variable for most pressure-retaining procedures. A procedure qualified without PWHT cannot be applied to production requiring PWHT. A new qualification with PWHT is needed.

Question 24Welding inspection and quality assurance

An austenitic stainless steel weld shows chromium carbide precipitation in the HAZ after prolonged exposure at 450–850°C. What is the likely consequence?

  1. Improved toughness in the HAZ
  2. Increased magnetic permeability throughout the weld
  3. Elimination of residual stresses
  4. Lower corrosion resistance in the sensitized zone Correct answer.

Explanation

Chromium carbides precipitate at grain boundaries in this temperature range, depleting chromium from adjacent metal. The sensitized zone then has reduced corrosion resistance, especially in aqueous chloride or acid service. This is not a method for improving toughness or relieving stress.

Question 25Welding inspection and quality assurance

A sampling plan requires examination of 10% of production welds and accepts the lot if no defects are found. What is a key limitation of this plan?

  1. It is valid only when the welds are inspected by radiography
  2. It guarantees that every weld meets the acceptance criteria
  3. It removes the need for welder qualification
  4. Low defect rates can be missed, so defective lots may pass Correct answer.

Explanation

Sampling inspection provides evidence about a lot but cannot prove that every weld is sound. A small sample can miss a low defect rate, so some defective lots may be accepted. Welder qualification and procedure control remain necessary regardless of the sampling plan.

Question 26Welding inspection and quality assurance

What is the main purpose of a procedure qualification record (PQR)?

  1. To specify the design pressure and temperature of a pressure vessel.
  2. To certify an inspector's qualification to perform visual examination.
  3. To record the actual welding parameters and test results that support a WPS. Correct answer.
  4. To list the welders who are employed by the fabrication shop.

Explanation

A PQR documents the variables used to make a qualification test coupon and the mechanical test results obtained from it. It is the evidence that supports the ranges and conditions written into a welding procedure specification.

Question 27Welding inspection and quality assurance

Which examination method is most suitable for detecting surface-breaking cracks in a ferromagnetic steel weld?

  1. Ultrasonic testing
  2. Radiographic testing
  3. Hardness testing
  4. Magnetic particle testing Correct answer.

Explanation

Magnetic particle testing detects surface and near-surface discontinuities in ferromagnetic materials by leakage fields around a crack. Radiography and ultrasonic testing are used mainly for internal flaws, and hardness testing measures resistance to indentation rather than cracks.

Question 28Welding inspection and quality assurance

What should a welding inspector verify during a pre-weld fit-up check?

  1. The radiographic density of the finished joint.
  2. The tensile strength of the base metal certificate.
  3. Joint alignment, root gap, and bevel preparation. Correct answer.
  4. The final hardness of the completed weld.

Explanation

Fit-up inspection confirms that the joint geometry matches the WPS before welding begins. Alignment, root gap, bevel angle, and cleanliness are checked because they affect penetration, distortion, and final weld quality.

Question 29Welding inspection and quality assurance

What does an inspector normally confirm by using a temperature-indicating crayon near a weld joint?

  1. The preheat or interpass temperature. Correct answer.
  2. The welding cable polarity.
  3. The shielding gas dew point.
  4. The base metal chemical composition.

Explanation

Temperature-indicating crayons change state at a marked temperature and are used to verify that preheat or interpass temperature is within the range required by the WPS. They do not measure chemical composition, polarity, or gas moisture.

Question 30Welding inspection and quality assurance

During GMAW, the inspector observes a shielding gas flow of 8 L/min while the WPS requires 15 to 20 L/min. What is the most appropriate action?

  1. Record the reading and accept the weld if visual inspection is satisfactory.
  2. Allow welding because gas flow has little effect on weld quality.
  3. Stop welding and have the flow rate corrected before work continues. Correct answer.
  4. Increase travel speed to compensate for the low flow.

Explanation

A shielding gas flow below the qualified range can leave the molten weld pool unprotected and cause porosity or poor fusion. The WPS must be followed, so welding should stop until the flow is corrected and the condition is documented.

Question 31Welding inspection and quality assurance

What is the primary purpose of an inspection and test plan (ITP)?

  1. To record the welder's hourly production rate.
  2. To replace the welding procedure specification on the shop floor.
  3. To calculate the minimum design thickness of a pressure vessel.
  4. To define inspection activities, acceptance criteria, and hold or witness points. Correct answer.

Explanation

An ITP sets out what will be inspected or tested, by whom, at what stage, and against which acceptance criteria. It also identifies hold and witness points so that quality activities occur in the planned sequence.

Question 32Welding inspection and quality assurance

An NDT technician performs ultrasonic examination after the certification expiration date on the qualification card. How should the inspection results be treated?

  1. They are valid only for welds that were completed before the expiration date.
  2. They are invalid because certification had expired at the time of examination. Correct answer.
  3. They remain acceptable because the technician has many years of practical experience.
  4. They become acceptable once a supervisor signs the examination report.

Explanation

NDT results are accepted only when the examination is performed by personnel whose certification is valid for the method and level used. An expired certification means the technician was not qualified at the time of the examination, so the results cannot be relied upon without re-examination.

Question 33Welding inspection and quality assurance

A nonconformance report proposes a "use-as-is" disposition for a weld that exceeds the acceptance criteria. Who should approve this disposition?

  1. The NDT technician who found the indication.
  2. The welder who made the weld.
  3. The storekeeper who issued the filler metal.
  4. The responsible engineering authority. Correct answer.

Explanation

A use-as-is disposition accepts a condition that does not meet the original specification, so it requires an engineering evaluation of fitness for service. The responsible engineering authority has the design and technical basis to approve or reject that disposition.

Question 34Welding inspection and quality assurance

A WPS limits interpass temperature to 250°C. The inspector measures 280°C immediately before the next pass. What should be done?

  1. Continue welding because the higher temperature improves fusion.
  2. Stop welding and let the joint cool to the qualified range. Correct answer.
  3. Add a tempering pass at a higher current.
  4. Reduce the preheat and continue without recording the event.

Explanation

Interpass temperature is a qualified variable that affects toughness, distortion, and metallurgical structure. Welding should be paused until the joint cools into the WPS range, and the excursion should be documented for quality review.

Question 35Welding inspection and quality assurance

Why is ultrasonic testing often preferred over radiography for detecting planar flaws in thick-section butt welds?

  1. It is more sensitive to planar flaws such as lack of fusion. Correct answer.
  2. It can be performed by any welder without a separate qualification.
  3. It produces a permanent photographic record that is easy to archive for many years.
  4. It requires no surface preparation, couplant, or access to the weld root.

Explanation

Ultrasonic testing is generally more effective for planar discontinuities, such as lack of fusion, because the sound beam can be directed at the flaw orientation. Radiography is more effective for volumetric flaws and may miss tight planar defects depending on orientation.

Question 36Welding inspection and quality assurance

What is the quality assurance purpose of maintaining a welder continuity log?

  1. It shows that a welder has used the qualified process within the required period. Correct answer.
  2. It records the chemical analysis of each base metal heat.
  3. It documents the design basis for post-weld heat treatment.
  4. It lists the calibration dates of all NDT equipment.

Explanation

A continuity log tracks whether a welder has used the qualified welding process within the period allowed by the applicable code or standard. If continuity is broken, the welder may need requalification before production welding.

Question 37Welding inspection and quality assurance

Why is a weld map used in a fabrication quality program?

  1. It gives the welder a shortcut for calculating heat input.
  2. It links each weld to its WPS, welder, and examination records. Correct answer.
  3. It replaces the need for visual inspection of completed welds.
  4. It specifies the chemical composition of the shielding gas.

Explanation

A weld map identifies each weld and ties it to the procedure, welder, and inspection or test records that apply to it. This traceability supports investigation, repair control, and final documentation.

Question 38Welding inspection and quality assurance

A PQR supports impact testing at -20°C, but the production specification requires service at -40°C. What is the QA consequence?

  1. The PQR can be used because lower service temperature does not affect welds.
  2. The WPS can be revised by the welder without additional testing.
  3. Only the welder needs a new performance qualification for -40°C.
  4. The existing qualification does not cover the production condition without further qualification. Correct answer.

Explanation

Procedure qualification covers only the conditions and ranges that were actually tested. A lower impact-test temperature is outside the supported range, so additional qualification is needed before the WPS can be used for that service.

Question 39Welding inspection and quality assurance

Porosity appears repeatedly across several welders and shifts on the same gas-shielded welding line. Which conclusion is most consistent with quality assurance principles?

  1. Each welder should be requalified before further production.
  2. The porosity is acceptable because it occurs across multiple welders.
  3. A common process or consumable problem should be investigated. Correct answer.
  4. The inspection method is probably producing false indications.

Explanation

A defect pattern that appears across different welders and shifts points toward a shared cause such as gas supply, filler metal, equipment, or procedure. Quality assurance would investigate the system rather than assume that every welder independently lost skill.

Question 40Welding inspection and quality assurance

A procedure qualification coupon passes tensile testing but fails the guided bend test. What does this usually indicate?

  1. The tensile test result must be discarded.
  2. The base metal certificate is automatically invalid.
  3. The weld has a ductility or soundness problem that prevents qualification. Correct answer.
  4. The bend test is not required for procedure qualification.

Explanation

The guided bend test exposes ductility and soundness near the weld and heat-affected zone. A failed bend test means the procedure has not demonstrated acceptable weld quality, even if the tensile test passed, so qualification is not complete.

Question 41Welding processes, procedures, and welder qualification

In the AWS electrode classification E7018, the digit "8" indicates that the electrode:

  1. has a high-hydrogen coating and runs on DCEN only, fast freeze
  2. has a low-hydrogen coating with iron powder, AC or DCEP Correct answer.
  3. has a cellulosic coating and runs on DCEP only, deep penetration
  4. has a rutile coating with iron oxide and runs on AC only

Explanation

In the four-digit SMAW system the first two digits give minimum tensile strength in ksi, the third digit gives the welding position, and the fourth digit covers coating type and usable current. The suffix "8" denotes a low-hydrogen coating containing iron powder that will run on alternating current or direct current electrode positive. Such electrodes are stored and handled to keep the coating dry because moisture is a source of diffusible hydrogen.

Question 42Welding processes, procedures, and welder qualification

In gas tungsten arc welding with direct current electrode negative, roughly what share of the arc heat enters the workpiece?

  1. About one-third
  2. About two-thirds Correct answer.
  3. About nine-tenths
  4. About one-half

Explanation

With the electrode negative, electrons flow from the tungsten to the work, so most of the kinetic energy is released at the workpiece. Approximately two-thirds of the arc heat goes into the base metal and about one-third into the electrode. This distribution gives deep penetration but requires a relatively large electrode to carry the current.

Question 43Welding processes, procedures, and welder qualification

Which document gives the welder the specific values to use in production and is supported by qualification test records?

  1. The welder performance certificate, which lists the welder's name
  2. The procedure qualification record, which lists measured test results
  3. The welding procedure specification, which states production values Correct answer.
  4. The inspection report, which records the NDE results

Explanation

The welding procedure specification is the written instruction that production welding must follow, listing values such as current range, voltage, travel speed, and preheat. It is supported by a procedure qualification record, which documents the actual parameters and test results obtained when the procedure was qualified. The PQR is a historical record, not a production instruction.

Question 44Welding processes, procedures, and welder qualification

Which change to a qualified welding procedure normally requires requalification?

  1. Removing the backing strip from a single-V groove weld Correct answer.
  2. Changing electrode brand within the same AWS classification
  3. Increasing current within the qualified range of the WPS
  4. Increasing preheat above the minimum value qualified

Explanation

Backing is an essential variable for procedure qualification, so deleting the backing strip changes the essential conditions and the procedure must be requalified. Raising preheat above the minimum, staying within the qualified current range, and substituting one brand for another within the same classification are not essential changes. Essential variables are those that, if changed, could affect the mechanical properties or soundness of the joint.

Question 45Welding processes, procedures, and welder qualification

What is the primary purpose of preheating a thick carbon steel joint before welding?

  1. To increase the tensile strength of the base metal before welding
  2. To reduce the amount of filler metal that the joint will need
  3. To allow the root pass to be deposited without any shielding
  4. To slow cooling and help prevent hard zones and hydrogen cracking Correct answer.

Explanation

Preheat raises the base metal temperature so heat is extracted more slowly after welding, which lowers the transformation temperature range and discourages formation of hard martensite. Slower cooling also gives diffusible hydrogen time to escape, reducing the risk of delayed hydrogen-assisted cracking in thick, restrained joints. Preheat does not raise strength or eliminate shielding requirements.

Question 46Welding processes, procedures, and welder qualification

A weld is made at 200 A and 25 V with a travel speed of 150 mm/min. What is the heat input?

  1. 2.0 kJ/mm Correct answer.
  2. 0.5 kJ/mm
  3. 1.0 kJ/mm
  4. 4.0 kJ/mm

Explanation

Heat input is calculated as voltage multiplied by amperage, multiplied by 60, divided by travel speed in mm/min and then by 1000. Here 25 x 200 x 60 equals 300,000, and the travel denominator is 150 x 1000, giving 2.0 kJ/mm. Heat input rises when current or voltage rises and falls when travel speed increases.

Question 47Welding processes, procedures, and welder qualification

During multipass welding to a qualified procedure, how should interpass temperature be controlled?

  1. Increase the current to compensate for a cooled joint
  2. Ignore the temperature because preheat has been applied
  3. Quench the joint with water before depositing each pass
  4. Measure the joint before each pass and stay within WPS limits Correct answer.

Explanation

Interpass temperature is the temperature of the joint immediately before the next pass is deposited, and the WPS sets both a minimum and a maximum. Exceeding the maximum can degrade toughness and mechanical properties, while dropping below the minimum risks hydrogen cracking. The welder must therefore check the temperature and stay within the qualified window.

Question 48Welding processes, procedures, and welder qualification

Which process uses a blanket of granular flux that is partly consumed and often recovered for reuse?

  1. GTAW
  2. FCAW
  3. SAW Correct answer.
  4. SMAW

Explanation

Submerged arc welding buries the arc under a layer of granular flux that melts to form a slag blanket and protects the molten pool. Unmelted flux is collected and reused, which is one reason the process is economical for long seams. Because the arc is hidden, the process is normally mechanized or semiautomatic and is used in the flat position.

Question 49Welding processes, procedures, and welder qualification

How does self-shielded flux-cored arc welding protect the molten weld metal?

  1. From an external cylinder of argon or carbon dioxide
  2. From flux ingredients in the wire that generate gas Correct answer.
  3. From the slag left behind by the previous pass
  4. From a vacuum chamber placed around the joint

Explanation

In self-shielded FCAW the tubular electrode contains fluxing and gas-forming ingredients that protect the arc and the weld pool without an external gas supply. Because no gas cylinder is needed, the process is tolerant of wind and is often used outdoors. Gas-shielded FCAW, by contrast, requires a separate shielding gas.

Question 50Welding processes, procedures, and welder qualification

Which gas metal arc transfer mode repeatedly touches the electrode to the puddle and gives relatively low heat input?

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

Explanation

In short-circuiting transfer the wire contacts the pool many times per second, extinguishing and re-establishing the arc with each cycle. Metal is transferred during the short circuit rather than by free flight, so the arc is cool and heat input is low. This makes the mode suitable for thin sheet and out-of-position work.