Coded Welder (EN ISO 9606) cheat sheet

EN ISO 9606 specifies requirements for qualification testing of welders for fusion welding of steels, and for other materials where applicable.

Normative references include EN ISO 9606-1 (steels), EN ISO 9606-2 (aluminium), EN ISO 9606-3 (copper), EN ISO 9606-4 (nickel), EN ISO 9606-5 (titanium), and EN ISO 14732 for welding operators.

Qualification testing according to EN ISO 9606 is based on the welding procedure specification (WPS) and is independent of the manufacturer's quality system.

Definitions: welder-person who performs welding; welding operator-person who operates mechanised or automatic welding equipment; examiner-person who verifies compliance with the standard.

Essential variable: a condition that, if changed, requires requalification of the welder.

Qualification range: the limits within which a qualified welder may work without requalification.

Test piece: the assembly welded for the purpose of qualification testing.

Examination and testing: visual, radiographic, bend, macro/micro, fracture tests as specified.

Certification: the issuing of a certificate of qualification by a certification body or an employer, as defined by the standard.

Process numbers according to EN ISO 4063: 111 = manual metal arc welding (MMA); 135 = metal active gas welding (MAG); 141 = tungsten inert gas welding (TIG); 311 = oxy-fuel gas welding.

EN ISO 9606-1 covers processes 111, 114, 121, 125, 131, 135, 136, 138, 141, 142, 143, 145, 146, 15, 311.

For process 141, the welder must be qualified for the specific type of current and, if applicable, for the use of filler wire.

Process 135 (MAG) requires qualification with the specific shielding gas type (e.g., CO2 or mixed gas) and transfer mode.

Process 311 (oxy-fuel gas welding) is typically qualified separately and is not interchangeable with arc welding processes.

Qualification for a process is limited to that process; a change from 111 to 135 requires new qualification tests.

Mechanised and automatic processes (e.g., 121, 125) require qualification of the welding operator according to EN ISO 14732, not EN ISO 9606.

Combination of processes: if two processes are used in one joint, the welder must be qualified for each process separately or as a combination if specified in the WPS.

Essential variables include: welding process, material group, consumable, position, thickness, joint type, and other factors as specified in the standard.

Material groups: grouping system according to EN ISO 9606-1 (e.g., Group 1.1, 1.2, 8.1) based on steel type; qualification in one group may cover others within specified limits.

Consumable: change from one consumable to another (e.g., from rutile to basic covered electrode) may require requalification, unless covered by the qualification range.

Position: qualification in a specific position (e.g., PA, PB, PF) covers other positions as defined in the standard; typically, qualification in the most difficult position covers easier ones.

Thickness: qualification on a test piece of thickness t qualifies a range of thicknesses, usually from t to 2t (for t ≥ 6 mm) or as specified.

Joint type: qualification on a butt joint covers fillet welds within limits; qualification on a fillet weld does not cover butt welds.

Pipe diameter: qualification on a pipe of diameter D covers diameters from D to 2D (for D ≤ 25 mm) or as specified.

For processes 141 and 311, the welder must be qualified for the specific type of current and, if applicable, for the use of filler wire.

Qualification ranges are detailed in tables of EN ISO 9606-1; each essential variable has specific coverage.

Test pieces shall be prepared according to the WPS and the standard; dimensions and joint preparation are specified in EN ISO 9606-1.

For butt welds, the test piece shall be of sufficient length to allow extraction of required test specimens; typical length ≥ 350 mm for plates, or as specified.

For pipe test pieces, the diameter and thickness shall be within the range to be qualified; minimum diameter may be 25 mm.

Joint preparation: edges shall be prepared (e.g., V-groove, U-groove) according to the WPS; for fillet welds, the test piece consists of two plates at right angles.

Welding shall be performed in accordance with the WPS, including preheat, interpass temperature, and welding parameters.

The welder shall only use the equipment and consumables specified in the WPS.

Test pieces shall be marked to identify the welder and the test piece before welding.

After welding, test pieces shall be allowed to cool naturally, unless otherwise specified.

The welder shall be responsible for the welding of the test piece; any assistance shall be noted and may invalidate the test.

Visual examination: the weld shall be examined visually for surface imperfections before other tests; acceptance criteria according to EN ISO 5817 (level B or C as specified).

Radiographic testing: for butt welds, radiographic examination may be required to detect internal imperfections; acceptance criteria according to EN ISO 5817.

Bend testing: root bend and face bend specimens are used to assess ductility and soundness; typically, two root and two face bends for butt welds.

Macro examination: a cross-section of the weld is examined to reveal the weld profile, penetration, and internal imperfections; required for fillet welds and some butt welds.

Fracture testing: for fillet welds, a fracture test may be used to assess the weld throat and fusion.

Micro examination: may be required for certain materials or processes to assess microstructure.

Test specimens shall be prepared according to EN ISO 9606-1 and relevant test standards (e.g., EN ISO 5173 for bend tests).

All test results shall be recorded in the qualification test record (QTR).

Acceptance criteria for imperfections are based on EN ISO 5817, with quality levels B, C, or D as specified in the standard; typically level B for welders.

Visual examination: no cracks, no lack of fusion, no excessive undercut (max 0.5 mm for level B), no porosity exceeding limits.

Radiographic testing: imperfections shall not exceed the limits of EN ISO 5817 level B; e.g., gas pores max 2% of area.

Bend testing: after bending, no crack or defect exceeding 3 mm in any direction, and no open defect exceeding 1 mm, unless otherwise specified.

Macro examination: the weld shall show complete fusion and penetration as required; no cracks or lack of fusion.

Fracture testing: the fracture surface shall not show lack of fusion, cracks, or excessive porosity.

If a test piece fails, the welder may be re-tested, but the conditions may be more stringent.

All test results shall be evaluated by an examiner and recorded in the QTR.

The period of validity of a welder qualification is typically 2 years, provided that the welder is continuously working with the qualified process and the employer confirms the validity every 6 months.

Confirmation of validity: the employer shall confirm every 6 months that the welder has been working without interruption and that the qualification remains valid.

Revalidation: if the welder has not worked for a period exceeding 6 months, or if there is doubt about the welder's skill, revalidation may be required.

Revalidation may consist of a new qualification test or a simplified test as specified in the standard.

The period of validity may be extended if the welder continues to work and the employer confirms validity every 6 months, up to a maximum of 2 years.

After the 2-year period, the qualification may be renewed by a new test or by revalidation as specified.

The certificate shall be endorsed at intervals not exceeding 6 months by the employer.

If the welder changes employer, the new employer is responsible for confirming the validity of the qualification.

A certificate of qualification shall be issued by a certification body or by the employer, as specified in the standard.

The certificate shall contain: welder's name, identification, date of birth, photograph, process, material group, consumable, position, thickness range, joint type, and period of validity.

The qualification test record (QTR) shall include all essential variables, test piece dimensions, welding parameters, and test results.

The QTR shall be signed by the examiner and the welder.

The certificate shall be endorsed by the employer at intervals not exceeding 6 months to confirm validity.

The certificate shall be available at the workplace for inspection.

The QTR shall be retained for a period specified by the standard, typically at least 5 years.

Certification bodies shall be accredited according to EN ISO/IEC 17024 or equivalent.

Personal protective equipment (PPE): welding helmet with appropriate filter shade, flame-retardant clothing, gloves, safety boots, and hearing protection where necessary.

Fume extraction: use local exhaust ventilation or respiratory protection to keep welding fume exposure below occupational exposure limits.

Fire precautions: remove flammable materials from the welding area, use fire blankets, and have fire extinguishers available.

Electrical safety: check welding cables and equipment for damage; ensure proper earthing and insulation.

Gas safety: secure gas cylinders upright, use flashback arrestors, and check hoses for leaks.

Hot work permit: obtain a permit where required and follow site-specific safety rules.

Workshop practice: keep the work area clean and tidy, store tools and consumables properly, and follow the WPS.

Emergency procedures: know the location of first-aid kits and emergency exits; report accidents immediately.