Overview - ISO 17652-2:2003 (Welding properties of shop primers)
ISO 17652-2:2003 specifies laboratory tests to assess how shop primers influence weldability and the formation of weld porosity. It is Part 2 of the ISO 17652 series and focuses on two reproducible test methods - the Rating test (screening) and the Weldability test (detailed assessment) - for use with common arc welding processes and welding consumables.
Key topics and technical requirements
- Two test methods
- Rating test: a screening procedure using a standard MAG (arc welding process 135) weld to compare relative weldability of primers by measuring porosity severity.
- Weldability test: produces a standard fillet weld to evaluate combinations of shop primer and welding consumables under conditions closer to production.
- Specimen preparation
- Rating test uses 10 specimens per primer (e.g., bright drawn steel plates 20 × 80 × 200 mm and 12 × 50 × 200 mm).
- Coating thickness must be uniform and as supplied; specimens are normally dried for at least 10 days at >10 °C and <40 °C with ≥50% relative humidity unless otherwise reported.
- Welding parameters (prescribed for rating test)
- MAG process (ISO 4063 process 135), shielding gas CO2 (C1), wire electrode G3Si1, 1.2 mm diameter, positive electrode polarity.
- Example prescribed settings include specified current, voltage and travel speed with ±5% tolerances, gas flow and stick-out; details are in the standard.
- Porosity evaluation
- Welds are broken (three-point loading) at ~150–250 °C to reveal pores.
- Pores smaller than 0.5 mm are ignored; examine a 100 mm length (excluding ends).
- Record number of pores >0.5 mm, total pore area (mm²), and mean pore area per pore.
- Reporting
- Mandatory test report items include primer ID, coating thickness, welding procedure, consumables, surface condition, porosity data and other test conditions.
Applications and users
- Who uses it
- Coating and primer manufacturers for product declarations.
- Welding engineers, fabricators and quality assurance labs assessing primer suitability for welded structures.
- Procurement and inspection teams validating primer/welding consumable combinations for production.
- Practical value
- Predicts relative tendency for porosity when welding over shop primers.
- Helps select primers and welding procedures to minimize weld defects and rework.
- Provides reproducible data for supplier claims and process approvals.
Related standards
- ISO 17652 series: Part 1 (General requirements), Part 3 (Thermal cutting), Part 4 (Emission of fumes and gases).
- Normative references cited: EN 439 (shielding gases), EN 440 (wire electrodes), EN 10025 (structural steels), EN ISO 2808, EN ISO 6947, and welding procedure specification standards.
Keywords: ISO 17652-2, shop primers, weldability, rating test, weldability test, porosity, MAG welding, fillet weld, welding consumables, testing procedure.