CAWI flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Essential variable
- A welding parameter that, if changed beyond the range qualified in the PQR, requires requalification of the WPS because it can affect the mechanical properties or integrity of the weld.
- PQR
- Procedure Qualification Record: a document recording the actual welding variables and the destructive test results used to qualify a welding procedure specification.
- WPS
- Welding Procedure Specification: a written, qualified document that provides the essential and nonessential variables for producing a weld that meets code requirements.
- Welder performance qualification
- A test of an individual welder's ability to produce sound welds, distinct from procedure qualification, and typically limited in position, thickness, and process.
- Carbon equivalent
- A formula combining carbon and alloying elements to estimate hardenability and cold-cracking susceptibility; higher values generally require preheat and low-hydrogen practices.
- Heat-affected zone
- The region of base metal that is metallurgically altered by welding heat but not melted; it is often the site of hardening, grain growth, and cracking.
- Sensitization
- Chromium carbide precipitation at grain boundaries in austenitic stainless steel when heated in the 425–870°C range, reducing corrosion resistance and causing intergranular attack.
- Weldability
- The capacity of a material to be welded under imposed fabrication conditions into a specific, suitably designed structure and to perform satisfactorily in the intended service.
- Hydrogen-induced cold cracking
- Delayed cracking that requires susceptible microstructure, diffusible hydrogen, and tensile stress; prevented by preheat, low-hydrogen consumables, and controlled cooling.
- Liquid penetrant testing
- A surface NDE method that uses a colored or fluorescent penetrant to reveal surface-breaking discontinuities in non-porous materials; not suitable for rough or porous surfaces.
- Magnetic particle testing
- An NDE method that detects surface and near-surface discontinuities in ferromagnetic materials by attracting magnetic particles to flux leakage fields; not applicable to austenitic stainless or aluminum.
- Ultrasonic testing
- A volumetric NDE method using high-frequency sound waves to detect internal discontinuities; sensitive to defect orientation and requiring calibrated equipment and qualified operators.
- Radiographic testing
- A volumetric NDE method using X-rays or gamma rays to produce an image of internal discontinuities; image quality depends on source size, detector resolution, and geometric unsharpness.
- Visual testing
- The primary NDE method that uses direct or aided vision to detect surface discontinuities such as undercut, overlap, spatter, and crater cracks; requires adequate lighting and access.
- Nonconformance report
- A document that records a deviation from code or specification, identifies the violated clause, and states the disposition: repair, rework, use-as-is, or reject.
- Level 1 inspector
- Under CSA W178.2, a certified inspector limited to visual inspection of welds, working under the direction of a higher-level inspector.
- Level 2 inspector
- Under CSA W178.2, a certified inspector qualified to perform visual and non-destructive examination of welds and to interpret results against the applicable code.
- Level 3 inspector
- Under CSA W178.2, the highest certification level, authorized to develop inspection procedures, interpret codes, and certify Level 1 and Level 2 inspectors.
- Inspection authority
- The right to accept or reject welded work, derived from the contract-specified code and the inspector's certification, not from personal preference.
- Traceability records
- Documentation linking each weld to its WPS, welder ID, filler lot, heat number, date, and inspection results, enabling verification and audit.
- SMAW
- Shielded metal arc welding: a manual process using a consumable covered electrode; electrode classification and current polarity are essential variables.
- GMAW
- Gas metal arc welding: a semi-automatic process using a continuous consumable wire and shielding gas; transfer mode and gas composition are essential variables.
- GTAW
- Gas tungsten arc welding: a process using a non-consumable tungsten electrode and separate filler; commonly used for aluminum with alternating current and argon shielding.
- FCAW
- Flux-cored arc welding: a process using a tubular consumable wire containing flux; slag protects the weld and process variables include polarity and gas shielding.
- SAW
- Submerged arc welding: a high-deposition process using a granular flux blanket to shield the arc; typically used for flat-position, thick-section welds.
- Preheat
- The application of heat to the base metal before welding to slow cooling, reduce hydrogen cracking risk, and improve fusion; an essential variable in many codes.
- Interpass temperature
- The temperature of the weld and base metal between passes; exceeding the maximum can degrade toughness and requires procedure review.
- Austenitic stainless steel
- A stainless steel family with an austenitic microstructure, generally non-magnetic and susceptible to sensitization and hot cracking; welded with low-carbon or stabilized grades.
- Aluminum oxide film
- A tenacious oxide layer on aluminum with a melting point much higher than the base metal; removed during GTAW by alternating current or by chemical/mechanical cleaning.
- Guided bend test
- A destructive test that bends a welded specimen to a specified angle to reveal surface discontinuities and assess ductility of the weld and heat-affected zone.
- Charpy V-notch test
- An impact test measuring the energy absorbed by a notched specimen, used to evaluate toughness of the weld metal and heat-affected zone.
- Acceptance criteria
- Code-specific limits on discontinuities such as undercut depth, porosity size, and reinforcement height that determine whether a weld is accepted or rejected.