Researchers at the University of Leicester have made a breakthrough in understanding why cracks occur during steel welding.
The study – part of the European Union-funded Mintweld project – found that solidification cracking in steel occurs due to miniscule breakages at the head of an existing crack, which then weaken the alloy.
This is the first time that researchers have observed solidification cracking in steel.
“Welding is the most economical and effective way to join metals permanently and it is a vital component of our manufacturing economy,” said University of Leicester professor Hong Dong.
“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].”
An X-ray beamline was used at the European Synchrotron Radiation Facility (ESRF) to observe crack formation, which can cause pollution and put lives at risk by weakening joints.
The findings were originally published in the journal Scientific Reports.