HIPFAT High Performance weldments in FATigue loaded vehicles; understanding & controlling weld defect formation

Purpose and goal

The HIPFAT project aimed to understand why welding defects Cold laps occur and how to avoid them, to create methods for defect-avoiding welding so desired service life can be reached. The goals were: - To identify or develop methods that can detect Cold laps. - To map out mechanisms and welding parameters that result in Cold laps. - To provide recommendations for how defect-avoiding welding can be achieved. These goals have been fulfilled. Detection methods are developed, important relationships identified, and recommendations developed. The general validity needs verification.

Expected results and effects

- Welding conditions affecting presence of Cold laps have been identified. - A bending method has been developed to quantify Cold laps. - Laser scanning algorithm has been developed, enabling new OFP method. - Recommendations have been made, based on optimum welding voltage for the filler material type used. - Several aspects of the weld geometry have been optimized. This enables the industry to further optimize the welding process, increase strength and reduce costs. This leads to an improved weld quality, a more efficient and sustainable manufacturing, and an increased service life.

Planned approach and implementation

The project was planned for 2.5 years in 6 work packages. Method development took long time, so an extension of 2 months was sought and granted. The consortium was also expanded with Chalmers when multi-factor analysis was decided, Chalmers expertise in this area is very good. WP1 Industrial requirements, cases, demonstrators WP2 Round robin WP3 Defect formation & Mechanism studies WP4 Detection of geometrical defects WP5 Verification of mechanisms and quality WP6 Project management & Dissemination The joint work in the project has been very good and important, a key to success.