Overview
ISO 9015-1:2001 - Destructive tests on welds in metallic materials - Hardness testing - Part 1: Hardness test on arc welded joints specifies how to perform hardness testing on transverse sections of arc‑welded joints. The standard focuses on Vickers hardness measurements (normally HV5/HV10) and describes test layouts, specimen preparation, and reporting to ensure the highest and lowest hardness levels in parent metal and weld metal are determined. It does not apply to austenitic stainless steels.
Key topics and technical requirements
- Test methods: Vickers hardness testing in accordance with ISO 6507-1, normally using loads of 49.03 N (HV5) or 98.07 N (HV10). Principles may be applied to Brinell (ISO 6506-1) and microhardness testing (ISO 6507-1 / ISO 9015-2).
- Specimen preparation: Cross‑sections are taken transverse to the weld and prepared mechanically and metallographically so the surface hardness is not metallurgically altered; etching is recommended to identify zones.
- Indentation layouts: Two approaches are defined:
- Rows of indentations (R) - series of indentations mapped across weld zones (parent metal, heat‑affected zone (HAZ), weld metal). Figures in the standard give typical layouts for butt, fillet and T‑joints.
- Individual indentations (E) - numbered areas for single indentations in parent metal, HAZ and weld metal (example areas 1–14).
- Spacing and positioning: Recommended centre‑to‑centre distances between indentations in the HAZ vary by material and load (e.g., smaller spacing for aluminium/copper alloys than for ferrous metals). For metals that harden in the HAZ, at least one indentation should be within 0.5 mm of the fusion line.
- Test conditions: Unless specified otherwise, testing is carried out at ambient temperature (23 ± 5 °C).
- Reporting: A test report is required; Annex A and B provide example report formats for rows (R) and individual indentations (E).
Practical applications and users
ISO 9015-1 is used for weld inspection, quality control and failure investigation where hardness across a welded joint is relevant. Typical users:
- Welding inspectors and non‑destructive testing (NDT) teams performing destructive verification
- Metallurgists and materials laboratories conducting hardness mapping
- QA/QC and fabrication engineers validating heat‑affected zone properties
- Certification bodies and application standards that reference weld hardness criteria
Related standards
Keywords: ISO 9015-1, hardness testing, Vickers HV5, HV10, Brinell, weld inspection, heat‑affected zone, arc welded joints, welded joint hardness, destructive testing.