Larger parts and components for armoured vehicles – floor and roof assemblies for instance – have to undergo a careful, so far manual welding process to ensure highest safety properties at and around the connection points of the steel plates. Stahlkontor, a Hagen (Germany) based specialist for the processing of high grade high strength steels for defence and civil applications, has now invented and patented a new fully automized joining technology. With their proprietary “Dual-LaserHybrid-Process (DLHP®)“, stress-induced risks of cracking and breakage in the welding zone are significantly reduced. The new process, which has successfully been submitted to comparative ballistic and blast tests at civil and defence authorities, has proved to be a reliable, safer and faster way to produce vehicle components made of armour steel.

The Dual-LaserHybrid-Process (DLHP®) combines simultaneous Laser and MAG welding with a special inductive heat treatment of the armoured steel plates. The main aspect of this process, relevant to safety properties, is the significant reduction of stress-induced risks of cracking and breakage in and around the weld seam, thus almost eliminating a potential weak point of the vehicle component when under the pressure loads of explosives or under ballistic attack. Being a fully mechanized, online-controlled, reproducible and comprehensively documented process, DLHP® welding also reduces some of the risks caused by the manual MAG welding process, which is now admissible and commonly applied in the safety and security environment.

Standardized tests reveal safety advantages
In the course of standardized material tests as well as in comparative ballistic and blast tests, DLHP® welded sheets of armour steel clearly surpassed the relevant mechanical technological values and results of conventionally welded test items (i.e. MAG; see diagrams 4-7). Apart from improved safety features as vital material and process requirements, DLHP® welding also shows serious advantages along the whole production chain of armoured defence components. Depending on the individual thickness of the base material, the new welding technology is several times faster than manual MAG welding. In addition, downstream re-finishing processes such as grinding of the seam and straightening of the welded sheets are rendered unnecessary – Both aspects exerting a significant influence on the overall production time of armoured vehicles and devices as well as constituting cost reducing factors without any safety trade-offs.

Approved by test authorities for defence technology
Following comprehensive internal development work and inhouse tests at Stahlkontor, comparative ballistic and blast tests according to WTD-standards have successfully been carried out at the German Test and Evaluation Unit for defence technology, the “Wehrtechnische Dienststelle (WTD)”. DLHP®-welding is now in its final phase of patent application and testing. Stahlkontor is planning to transfer the new joining technology to series production already during the last quarter of 2017.

Dual-LaserHybrid-Process (DLHP®)
Advantages and characteristics

  • significantly lower process times compared to MAG welding
  • narrower heat-affected zone in welding area
  • excellent mechanical-technological properties
  • consistent, single-layer weld seam with only slight convexity
  • no need for re-finishing processes of weld seam (grinding and straightening)
  • a constant, reproducible and fully documented process (fully mechanized and CNC-controlled)
  • comparative blast tests passed at the Wehrtechnische Dienststelle (WTD, German test and evaluation unit for defence technology)
  • ballistic tests passed according to WTD standards

Conclusion: DLHP® welding has proved to be a faster, safer, more reliable and cheaper process for welding armour steel.

Stahlkontor – specialized in the processing of armour steels
Stahlkontor is a worldwide operating, independent system supplier for parts and components made of high strength high grade steels for applications in the defence, aviation, industry and rail vehicles sectors as well as in various other civil application areas. The company with about 250 employees is based in Hagen, at the south-eastern end of the Germany’s traditional steel and coal region, the Ruhr Area. Deeply rooted in steel processing and special steel applications, Stahlkontor has years of experience in steel related knowledge of materials and processing. They now apply the latest design-, programming- and operating software controlling a state-of-the-art machine park and thus ensuring fast, economic and capacity adjusted order processing. Apart from highly flexible, inhouse available cutting, machining, beam splitting and joining techniques, Stahlkontor since late 2017 exclusively offers the Dual-LaserHybrid-Process (DLHP®) – a new patented joining technology developed inhouse and featuring the most advanced, safe and economic welding process for joining armour steel.
Further information: www.stahlkontor.com

For press contact / high-resolution pictures and diagrams:

NEXUS Text und Kommunikation
Dr. Dieter Koch
Tel: +49 234 2988163

For company contact:
Stahlkontor GmbH & Co.KG
Preußerstraße 28
58135 Hagen
Phone: +49 2331 9030-0
Fax: +49 2331 9030-30
Mail: info@stahlkontor.de
Web: www.stahlkontor.com