CAWI key terms

A written document that lists the variables and ranges a welder must follow to make a production weld, after that procedure has been proven by qualification testing.

The record of the test weld made to prove a welding procedure, documenting actual variables used and the mechanical test results that show the procedure produces sound welds.

A welding parameter, such as filler metal classification, preheat, or heat input range, that must be changed only by requalification because altering it can affect weld mechanical properties.

A welding parameter that may be changed without requalifying the procedure because it does not significantly affect weld strength or toughness, though the WPS may still need revision.

A test that demonstrates an individual welder can deposit sound weld metal to a specified standard, separate from the procedure qualification that proves the process itself.

A written statement, signed by the employer or an authorized body, confirming that a welder has passed the required performance qualification tests for a defined scope of work.

A test assembly of specified material and joint design welded under controlled conditions, from which specimens are cut for bend, tensile, or other mechanical testing.

The documented right of an inspector to accept, reject, or require rework, granted by the employer or code and limited to the scope of duties and standards specified.

Conformance of welding work, documentation, and inspection records to the requirements of the governing construction code and any project specifications invoked by contract.

The defined limits on discontinuity size, type, and distribution that determine whether an examined weld is accepted or rejected under the applicable code or specification.

An interruption in the normal structure or uniformity of a weld or base metal, such as porosity, slag, or undercut, that may or may not constitute a defect depending on acceptance criteria.

A discontinuity that exceeds the limits of the applicable acceptance criteria and therefore requires rejection, repair, or removal before the weld can be accepted.

The energy delivered per unit length of weld, usually expressed in kilojoules per millimeter, calculated from arc voltage, current, and travel speed, and influencing cooling rate and toughness.

The base metal adjacent to the fusion line that has been metallurgically altered by welding heat but not melted, often the region most prone to hardening or cracking.

The application of heat to the base metal before welding to slow cooling, reduce hydrogen pickup effects, and lower the risk of cracking in hardenable or thick materials.

Delayed cracking caused by dissolved hydrogen trapped in weld metal or the heat-affected zone combined with residual stress and a susceptible hardened microstructure.

A calculated value combining the effects of alloying elements such as carbon, manganese, and chromium to estimate a steel's hardenability and weldability, often guiding preheat decisions.

The capacity of a material to be welded under the imposed fabrication conditions into a specific, suitably designed structure that performs satisfactorily in service.

An arc welding process in which a covered electrode is consumed and its flux coating generates shielding gas and slag to protect the molten weld pool.

An arc welding process using a continuously fed solid wire electrode and an externally supplied shielding gas, available in short-circuit, globular, spray, and pulsed transfer modes.

An arc welding process using a tubular wire filled with flux, with or without additional shielding gas, offering high deposition rates and slag-protected weld metal.

An arc welding process using a nonconsumable tungsten electrode and separately supplied filler metal, producing precise, clean welds often used for root passes and thin materials.

A gas or gas mixture supplied to the arc region to exclude atmospheric oxygen and nitrogen, preventing oxidation and porosity in the molten weld metal.

The localized volume of molten metal formed by the arc that solidifies to become the weld bead, whose size and fluidity the welder controls through technique and parameters.

The specified arrangement of mating surfaces, including groove angle, root opening, and land, that determines accessibility, penetration, and required weld volume.

A weld that extends through the full thickness of the joint, with fusion achieved at the root, typically required where maximum strength is demanded by the design.

A groove weld that intentionally does not extend through the full joint thickness, used where design loads permit and often requiring a specified effective throat.

The primary non-destructive inspection method using the unaided eye and aids such as magnifiers and gauges to assess surface condition, bead profile, and visible discontinuities.

A groove melted into the base metal at the weld toe or root that is not filled by weld metal, reducing cross-section and concentrating stress under load.

Cavities in solidified weld metal formed by gas trapped during solidification, appearing as rounded voids that may be scattered, clustered, or aligned.

Nonmetallic solid material from flux or electrode coating entrapped in weld metal or between passes, reducing effective weld section and acting as a stress riser.

A discontinuity where weld metal fails to bond to the base metal or to a previous pass, often caused by low heat input, poor technique, or contaminated surfaces.

A destructive qualification test in which a transverse specimen is bent around a specified radius to reveal surface discontinuities and ductility problems in the weld region.

A destructive test that pulls a coupon until failure to measure ultimate strength and, for some specimens, yield strength and elongation of the weld or joint.

A volumetric non-destructive method that transmits high-frequency sound waves into the weld and interprets reflected echoes to detect internal discontinuities and measure their depth.

A volumetric non-destructive method that passes penetrating radiation through the weld onto film or a digital detector, producing an image showing internal density differences such as porosity or inclusions.

A surface and near-surface method that magnetizes the part and applies ferromagnetic particles, which gather at flux leakage fields caused by discontinuities in the material.

A surface method that applies a liquid penetrant to a cleaned weld, removes excess, and uses a developer to draw penetrant from surface-breaking discontinuities for visible indication.

The controlled fabrication and destructive testing of a test weld to establish that a proposed procedure, with its specified variables, will produce joints meeting code requirements.