General information on repair of vehicles with ultra-strength steels. - AH60.00-P-0024-01N
Failure to observe instructions when straightening/repairing, separating, preparing adhesive points, joining/connecting, resistance spot welding, MIG welding, MIG brazing can lead to considerable damage to ultra-strength steels and their joints.
Straightening/repairing ultra-high-strength steels
Straightening work
- Do not heat above 300°C
- Use commercially available pulling tool to planish the side longitudinal member, for example. Observe welding suitability resistance when installing pulling adapter (e.g. shims) on ultra high-strength steels.
- Straightening work on ultra high-strength steels can only be accomplished in the event of minor damage (dents).
Cutting ultra-high-strength steels
Heating gluing points
- The maximum permissible temperature for heating the flange connection to be loosened is 200°C.
- The ideal temperature for loosening the flange, e.g. with a chisel, is approx. 100 to 120°C.
- Do not heat adhesive connections, consisting of 3 sheets of metal, to temperatures exceeding 200°C to preserve the connection without permanent damage.
- After the component has cooled down, the adhesive resumes its original strength.
- We recommend a hot air gun as heat source.
- Drill out spot welds with special bits (see GOTIS).
- Cut out spot welds with special spot weld milling cutter (see GOTIS).
- Cut with Ø 30 mm cutting disks (see GOTIS).
- Use suitable machines for individual tools (see GOTIS).
- Drill rivet holes with special bits (see GOTIS).
Prepare gluing points
Observe pretreatment of bonding surfaces.
The detailed work description included with glue set must be strictly observed! Otherwise adhesion problems may occur.
Joining/connecting ultra-high-strength steels
Rivet joints
- When processing ultra-high-strength materials, use only high-strength rivets approved by Daimler AG.
- For this purpose, a riveter with increased draw-off strength is required (see GOTIS).
Resistance spot welding
- For this purpose, a riveter with increased draw-off strength is required (see GOTIS).
- The extension of the electrode arms is limited to the short standard electrode.
- To determine the optimum welding parameter settings and the electrode pressure, perform a snap-out test on a sample plate before performing resistance spot welding on the vehicle (see following picture).
- Only this ensures optimum welds
MIG soldering
MIG soldering is only permissible on repair points described in WIS.
Snap-out test on sample panel (old part) on ultra high-strength steels to determine the optimal welding parameter setting
- Determine suitable welding parameters on sample panel (to be removed from old part) in combination with approved spot welders. By completing spot-weld specimen (with adhesive) and performing snap-out test with measuring weld nugget diameter using formula 4X√t (t = panel thickness).
- Weld nugget diameter (a) should be at least 5 mm.
Take adhesive from glue cartridge without mixing tube (mix manually).