Overview
ISO 17641-2:2015 - Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 2: Self‑restraint tests defines specimen types, test-piece dimensions, test procedures and reporting for self‑restraint hot‑cracking tests on weld metals. It describes three self‑restraint methods - the T‑joint weld cracking test, the weld metal tensile test, and the longitudinal bend test - to assess the hot‑cracking sensitivity of weld metal produced by arc welding. The standard describes how to carry out and report the tests but does not provide acceptance criteria.
Key technical topics and requirements
- Scope and materials: Primarily intended for fully austenitic stainless steels, nickel, nickel‑base and nickel‑copper weld metals, but applicable to other weld metals.
- Test types:
- T‑joint weld cracking test (qualitative): single‑pass restrained fillet weld; three specimen types (A, B, C) with different restraint levels. Type B uses a 40 mm thick horizontal plate; Type C uses 10 mm stiffeners if a 40 mm plate is not available.
- Weld metal tensile test: cylindrical all‑weld‑metal specimens from butt welds; opens cracks formed during welding and can be assessed qualitatively or quantitatively using the microcrack sensitivity index (MSI).
- Longitudinal bend test: widens weld‑formed cracks for detection; may be reported qualitatively or using MSI.
- Procedure highlights:
- Welding according to a written WPS (reference: ISO 15614‑1).
- First fillet run (a1) made as continuous run in PB position with a throat ≥ 5 mm; second run (a2) started within 20 s.
- Examination: visual inspection (up to ×5 magnification); liquid dye penetrant may be used to aid crack detection.
- Principle: Cracks are generated during welding; tensile and bend methods apply additional strain to widen existing cracks for measurement and reporting.
Practical applications - who uses this standard
- Welding engineers and procedure qualification labs validating welding consumables and procedures for hot‑cracking susceptibility.
- Welding consumable manufacturers conducting qualification tests.
- Quality assurance/inspection teams, metallurgists and R&D groups assessing weld metal behavior under restraint.
- Fabricators using production weld coupon tests to monitor susceptibility in manufacturing.
Note: ISO 17641‑2 is for evaluating weld metal sensitivity, not parent‑metal assessment; acceptance limits must be set by the user, purchaser or project specification.
Related standards
Keywords: ISO 17641-2:2015, hot cracking tests, weldments, self‑restraint tests, arc welding, T‑joint weld cracking test, weld metal tensile test, longitudinal bend test, microcrack sensitivity index, welding procedure qualification.