Recommendations for the spot welding of galvanized ahss high-ductility steels
"HD welding may be frightful, but the tips are so delightful. Let them snow, let them snow, let them snow!"
Galvanized ahss high-ductility steels are like Christmas and Easter combined for forming specialists. They are highly corrosion-resistant and exhibit high-strength and excellent formability. Welding specialists see this in a more differentiated way, especially with respect to liquid metal embrittlement. Liquid zinc penetrates the grain boundaries of the steel and damages the joint. Such penetration can be avoided.
Generally, the following applies:
- voestalpine ahss high-ductility steels (complex-phase and dual-phase steels) in strength classes 600 and 800 MPa do not differ significantly from the classic ahss steels in their resistance to liquid metal embrittlement. Weldability is sufficient.
- Proper welding equipment must be used in order to meet all pertinent requirements in the welding of high-strength steels. Such equipment is mandatory, especially with respect to liquid metal embrittlement.
It’s snowing expert suggestions:
It isn’t Santa Claus but a welding expert who brings us special recommendations for Merry Welding all year round. These suggestions have been proven in practice and are frequently used by OEMs.
- Use high electrode forces, preferably between 4 and 5 kN.
- Enlarge electrode tip diameter, for example from 6 mm to 8 mm, or use flat electrode caps.
- Use highly rigid spot welding guns, preferably C type to X type
What will the future bring?
ahss high ductility dual-phase and ahss high ductility complex-phase steels with tensile strengths in excess of 1000 MPa are particularly interesting in lightweight automotive design. voestalpine is a leader in the development of these high-quality steels and is working to reduce liquid metal embrittlement sensitivity by fine-tuning alloying and welding processes.