New research led by the University of Leicester in the UK has made a novel breakthrough in understanding how solidification cracking occurs during the welding of steel, an important engineering alloy. In an open-access paper in the journal Scientific Reports, the team proposes that solidification cracks grow by linking micro-porosities in the meshing zone in the solidifying weld pool. This is the first time that researchers have observed solidification cracking in steel and sheds new light on why the alloy may crack during the process.
The team used synchrotron X-ray beamline at the European Synchrotron Radiation Facility (ESRF) to observe the crack formation at the real time.
Welding is the most economical and effective way to join metals permanently and it is a vital component of our manufacturing economy. It is estimated that more than 50% of global domestic and engineering products contain welded joints. In Europe, the welding industry has traditionally supported a diverse set of companies across the shipbuilding, pipeline, automotive, aerospace, defence and construction sectors. Solidification/hot cracking is the most common failure mode during metal processing, such as welding, casting and metal additive manufacturing (metal 3D printing).—Professor Hong Dong from the University of Leicester Department of Engineering
The study is part of the team’s international EU FP7 project Mintweld, working with eleven partner originations from 7 EU countries.
The research was funded by an EPSRC industrial CASE project with Tata Steel UK and was also supported by the European Commission as a part of the FP7 programme, Modelling of Interface Evolution in Advanced Welding (MintWeld); Contract No. NMP3-SL-2009-229108.
L. Aucott, D. Huang, H. B. Dong, S. W. Wen, J. A. Marsden, A. Rack & A. C. F. Cocks (2017) “Initiation and growth kinetics of solidification cracking during welding of steel” Scientific Reports 7, Article number: 40255 doi: 10.1038/srep40255