The Influence Surface Treatment on the Firmness of Spot Welds

Abstract

. Spot welding is a commonly used technology in practice to join metal material. It applies to all types of production, mass, series and piece production. Its biggest advantage is the high productivity, with which it is possible to weld. As with other welding methods, the cleanliness of the welded surfaces is important. The aim of the tests performed was to evaluate the influence surface treatment on the firmness of the test specimens of spot welds. The test specimens were made from steel. Welding was done while using manual clamp welders. Four sets of metal sheets were prepared before the welding, with different surface treatment - surface without treatment (original, not degreased), only degreased, grinded and degreased, blasted and degreased. The test specimens were made using different welding times, from 0.1 sec. to 2.0 sec. Then, they were loaded on a universal test instrument until destruction. All measured values were statistically evaluated. The evaluations show that although it is possible to weld sheets without surface treatment, it is not recommended. There is no statistically significant difference between the results of other types of pre-treatments.