Overview
EN ISO 15609-4:2009 - Specification and qualification of welding procedures for metallic materials - Welding procedure specification - Part 4: Laser beam welding (ISO 15609-4:2009) defines the required content of a Welding Procedure Specification (WPS) for laser beam welding processes, including overlay welding. It sets out which variables and dimensions influence metallurgical, mechanical and geometrical properties of laser-welded joints. The standard is explicit that it is not applicable to other cladding processes (for example thermal spraying).
Key topics and requirements
The standard details the technical content that a WPS for laser beam welding should include. Key elements are:
- Welding process identification (ISO 4063 process number for laser welding)
- Manufacturer and WPS identification, and reference to the Welding Procedure Qualification Record (WPQR)
- Equipment and laser parameters:
- laser source type (e.g. Nd:YAG, CO2), nominal power, continuous or pulsed operation
- beam quality parameters (TEM mode, beam divergence, wavelength, polarization, Beam Parameter Product)
- beam delivery and focusing (fiber/mirror transmission, collimators, beam shaping, scanners)
- focal length, focal spot, working distance and beam shaping methods
- Parent and filler materials, including ranges and tolerances for thickness and metallurgy
- Joint design, preparation and welding position, including jigs, fixtures, backing and tolerances
- Welding technique and parameters: passes, tacking, slope up/down, overlap, cosmetic pass, carrier gas for overlay
- Preheating, post-weld heat treatment and post-weld operations
- Ranges and tolerances appropriate to manufacturing experience; examples of WPS formats are provided in the annex
The document also defines terms specific to beam welding (working distance, focal spot, beam shaping, etc.) and lists variables that influence welded-joint quality.
Applications and who uses it
EN ISO 15609-4:2009 is intended for:
- Welding engineers and procedure writers who prepare WPS for laser beam and overlay welding
- Manufacturers and fabricators using laser welding equipment (automotive, aerospace, tooling, medical devices, energy)
- Quality managers, inspectors and certification bodies who verify compliance of welding documentation and WPQRs
- Designers and production planners needing to specify laser welding parameters and acceptance ranges
Using this standard helps ensure consistent, traceable WPS documentation and supports qualification and reproducible joint quality for laser welding processes.
Related standards
Keywords: EN ISO 15609-4:2009, welding procedure specification, WPS, laser beam welding, overlay welding, laser welding equipment, beam parameter product, WPQR.