A presentation by Michael Palko, Ford Motor Company, at 2018 Great Designs in Steel.
This presentation summarizes work in two Auto/Steel Partnership (A/SP) projects, gas metal arc welding (GMAW) of advanced high-strength steel (AHSS) and improved fatigue of GMAW. The first project was focused on the development and validation of a generic brazing and GMAW approval process for AHSS for use by the automakers. The project team identified four different AHSS grades for evaluation. Two steels were welded using gas metal arc welding techniques and the welds produced were tested using X-ray and quasi-static lap shear tensile tests. The other two steels were welded and brazed using different fillers to evaluate differences in filler strength materials. Micro-hardness and metallurgical examinations were conducted to evaluate the welds. Lap tensile shear coupons for coated and uncoated steels were tested to determine tensile shear strength, fracture locations and other weld metallurgical properties.
In the second project, the project team developed a bending test for lap shear coupons and conducted bending fatigue testing of select AHSS to establish baseline fatigue properties of GMAW. The results of the testing will be presented followed by a discussion on the advantages and disadvantages of the bending fatigue test setup and future work to optimize bending weld fatigue.