Process control for joining
Products – in this case, mainly welded steel pipe – must provide increasingly complex combinations of properties, e.g. strength, toughness, corrosion resistance or fatigue resistance.
Welding fundamentally alters a material – and therefore its properties. In order to obtain the desired combination of properties, we develop suitable parameter combinations for various welding techniques.
Along with the actual welding process, it is also particularly important to consider the effects of heating and – where used – of the filler material. We have appropriate, effective laboratory equipment for submerged arc, various gas metal arc, high-frequency induction, and laser beam welding methods. Alternatively, we support optimization on-site in production facilities. Ask us about it!
Most thick wall pipes are produced by submerged arc welding (SAW). This process is extremely reliable, robust and very economical, especially when multi-wire systems are used.
Versatile process applications.
This process is most often used in industrial manufacturing. In pipe production, e.g. in preproduction to connect steel strips and to make tack welds in longitudinal or spiral welded pipes. Due to its versatility and ease of controlling heat input, it is often used for girth welds.
This process is characterized by extremely high productivity and is used for longitudinal welded pipe with thin to medium wall thicknesses. The coil edges are heated up to a softened state by high-frequency electric current and then pressure welded.
We call this RoSA (Rohrschweißapparatur = pipe welding apparatus).
With our RoSA unit, we investigate various parameters associated with the high-frequency induction welding (HFI) of pipe materials with a sheet thickness of up to 15 mm, e.g. to
- Expand the production range of materials suitable for HFI-welding
- Modify processes for improved weld properties
- Enhance our understanding of the process
Welding power up to 300 kW; maximum upset pressure 60 kN.
Modern joining method.
In laser beam welding, welding energy can be applied very precisely. Advantages of laser beam welding are the concentrated application of energy and high welding speed. The resulting productivity is greater than that of conventional arc welding methods and the area near the weld is subjected to a lower thermal load.
We characterize grade and surface developments for the automotive sector, but also the weldability of thick hot rolled strip.
Our YAG laser test unit (YLVa = YAG-Laser-Versuchsanlage) has a maximum output of 16 kilowatts. To improve the gap-bridging capability of the laser process, we have installed an additional combination with arc welding technology and a beam oscillation function. To influence the weld microstructure in a specifically targeted manner, a process-integrated inductive heat treatment can be applied. Ask us about it!
Innovative joining technology.
In automotive construction, but also in the “white goods” segment, many materials are joined by this joining method.
Unlike welding, it can be used to reliably join surface-sensitive and non-conductive materials as well as mixed connections with thermally incompatible metals. Clinching is about as economical as spot welding. We have two hydraulic clinch systems (2-column frame, automated clinching in the robot cell). Along with preparing samples of the connection, we use a robot interface to draw conclusions about the service life of punches and dies depending on the material and/or the surface finish used.
Hollow and half-hollow self-pierce rivet systems are used to join dissimilar materials in structural applications requiring high transmission forces. With ultra-high-strength steels, selecting a suitable rivet system is particularly important for ensuring the process reliability of the joint.
With the U-bolt system and a 2-column frame, we can join all available rivet systems.
In connecting dissimilar materials, industrial adhesives based on single and two-component systems play a key role.
Our modern adhesives laboratory is equipped with an exhaust hood, application technology for single and two-component adhesives, and a curing oven, in order to provide reliable adhesives technology. In addition to standardized reliability tests, adhesive-based zinc bonding tests are also conducted.