Cost Affecting Factors Related to Fillet Joints

Paper in proceeding, 2013

Fillet welds are by far the most frequent arc welding joint type in the fabrication industry with about 80% of all arc welded joints worldwide. Alt-hough the joint is well established, there are many aspects to consider when pro-ducing an ideal weld. This paper reveals and connects several problematic issues related to the joint type and the difficulties to fabricate a weld with correct strength, cost, and quality. Excessive welding of fillet welds is common, resulting in increased fabrication cost. There could be several causes for this; the designers do not customize the weld demand for the different stress levels and the production adds even more to handle the variation in the process. Previous studies shows that the combination of these factors can result in 100% extra weld metal, compared to what should be needed to fulfil the strength demands. Inspections are another contributor to excess welding. The capability of the weld size measurement method used by welders and inspectors is unsatisfactory. Measurement system analyses show that the scatter from the measurement system itself is in the same range as the scatter from the process. A critical summary of the current state-of-the-art is that fillet welds are hard to specify and fabricate with the right size, that the measuring method is incapable and the connection between size and strength is weak.