Authors: Mohamed Bouzekri Sylvain Dancette Thomas Dupuy Arnaud Lens Bouchra Nait Oultit Véronique Massardier Damien FabrÈgue Helmut Klocker
Publish Date: 2013/01/16
Volume: 54, Issue: 3-4, Pages: 3-14
Abstract
On the shop floor as in laboratories destructive testing remains the main means of quality control of spot welds After hand or mechanized weld destruction the socalled “plug diameter” is measured and is usually considered a good indicator of the weld quality However it turns out that the “plug” failure of spot welds is far from being the rule Moreover fracture may occur in different zones of the weld leading to very different meanings of the plug diameter Therefore the plug diameter is most of the time not wellcorrelated with the weld strength which is the main value of the spot weld Partial or full interfacial failures through the weld nugget exhibit equivalent mechanical strengths and therefore should not be rejected Through this work it is shown that the failure type depends on various parameters nugget diameter sheet thickness loading mode … and consequently it is not an intrinsic property of the steel grade In this way recommended quality criteria are based on weld strength weld diameter including the interfacial fracture area if any or absorbed energy independently of failure occurrence In addition nondestructive techniques might be key investigation methods and have to be developed further
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