Overview
ISO 3581:2023 - Welding consumables - Covered electrodes for manual metal arc welding of stainless and heat‑resisting steels - Classification - defines classification rules for covered electrodes used in manual metal arc (MMA) welding of stainless and heat‑resisting steels. The standard classifies covered electrodes by the all‑weld metal chemical composition, type of electrode covering, mechanical properties (as‑welded or heat‑treated), and other electrode properties. ISO 3581:2023 is a combined standard that supports two distinct classification systems - ISO 3581‑A (nominal composition) and ISO 3581‑B (alloy type) - and provides harmonized symbols, test requirements and delivery conditions.
Key topics and technical requirements
- Two classification systems:
- ISO 3581‑A (nominal composition) - designation components indicate nominal levels of key alloying elements.
- ISO 3581‑B (alloy type) - family‑based three‑ or four‑digit alloy type designations and modifiers.
- Note: the systems are not equivalent and must be used independently.
- Symbols and designation rules for product/process, electrode covering type, nominal electrode efficiency, current type, and welding position.
- Required tests for classification (vary by electrode size and welding position):
- Chemical analysis of deposited all‑weld metal.
- Mechanical property tests (tension, as‑welded or heat‑treated conditions), including provisions for preheat/interpass and pass sequence.
- Fillet weld positional tests to verify weldability and positional capacity.
- Annex B provides guidance on considerations for weld metal ferrite content, important for stainless and heat‑resisting steel weld properties.
- Technical delivery conditions and examples of designation are included to aid procurement and product labeling.
- Normative references include ISO 544, ISO 6847, ISO 14344 and ISO 15792 (test methods and delivery conditions).
Practical applications and intended users
ISO 3581:2023 is intended for:
- Welding engineers and metallurgists specifying filler selection for stainless and heat‑resisting steels.
- Manufacturers of covered electrodes for product classification, testing and labeling.
- Fabricators and contractors who need to match electrodes to process, base metal and required mechanical/chemical properties.
- Purchasing and quality assurance teams creating procurement specifications and acceptance criteria for welding consumables.
- Standards bodies and certification organizations harmonizing product designations internationally.
This standard helps ensure consistent classification, traceability and fitness‑for‑purpose of covered electrodes used in MMA welding of corrosion‑resistant and high‑temperature steels.
Related standards (normative references)
- ISO 544 - Technical delivery conditions for filler materials and fluxes
- ISO 6847 - Deposition of a weld metal pad for chemical analysis
- ISO 14344 - Procurement of filler materials and fluxes
- ISO 15792 (parts) - Test methods for preparation and classification testing
Keywords: ISO 3581:2023, covered electrodes, manual metal arc welding, stainless steel welding, heat‑resisting steels, electrode classification, all‑weld metal composition, fillet weld test, weld metal ferrite.