Overview
EN ISO 17642-2:2005 - Destructive tests on welds in metallic materials - Part 2: Self‑restraint cold cracking tests - specifies test-piece sizes, specimen preparation and procedures for assessing cold cracking sensitivity during arc welding. It covers the CTS (Controlled Thermal Severity) test and the Tekken (Y‑groove) / Lehigh (U‑groove) self‑restraint tests, and is intended primarily for C‑Mn and low‑alloy steels and arc welding processes (covered electrodes and GMAW). The standard defines how to deposit test welds, control thermal conditions and examine results to determine susceptibility to hydrogen‑induced cold cracking.
Key topics and requirements
- Test methods: CTS test and Tekken/Lehigh (Y‑ and U‑groove) self‑restraint procedures to reveal cold‑cracking in weld metal and heat‑affected zones.
- Test-piece dimensions and tolerances: Example CTS dimensions include top block (75 ± 1 mm × 75 ± 1 mm × t), bottom block (250 ± 3 mm × 100 ± 3 mm × t), minimum material thickness t = 6 mm.
- Preparation and assembly: Machining, surface finish limits (mating faces Rmax 3.2 µm; weld area 6.3 µm), bolt assembly (12 mm bolt; torque (100 ± 5) N·m), rolling direction alignment and minimum mating‑face gap.
- Anchor welds: Use consumables with yield strength ≥ parent material up to 895 N/mm²; specified throat sizes for anchor fillets (e.g., (6 ± 1) mm for plates ≤15 mm).
- Thermal control: Preheat, post‑heat and controlled cooling (transfer to cooling bath within 60 s; immersion depth (60 ± 5) mm; bath exit temperature ≤ 30 °C). Timings include 12 h rest after anchor welds, 48 h minimum between first and second test welds and before sectioning.
- Measurements and evaluation: Metallographic sectioning, qualitative and quantitative evaluation of surface/root cracks, heat‑input calculation (kJ/mm) and diffusible hydrogen determination per EN ISO 3690.
- Limitations: Generally not intended for high‑current submerged‑arc welding.
Applications and users
This standard is used by:
- Welding engineers and procedure qualification teams to evaluate cold‑cracking risk of base metals and consumables.
- Materials and quality assurance laboratories performing destructive weld tests.
- Consumable manufacturers assessing hydrogen sensitivity and recommending preheat/post‑heat.
- NDT and metallography specialists conducting sectioning and crack assessment.
Practical outcomes include validated welding procedures, improved consumable selection, and reduced hydrogen‑induced cracking in welded structures.
Related standards
- EN ISO 17642‑1:2004 (General)
- EN ISO 3690 (Hydrogen determination in weld metal)
- EN 1321 (Macro/micro examination)
- EN 1043‑1 (Hardness testing on arc welded joints)
Keywords: EN ISO 17642-2:2005, cold cracking tests, self‑restraint tests, CTS test, Tekken Y‑groove, Lehigh U‑groove, weld cracking sensitivity, arc welding, C‑Mn steels, hydrogen determination.
