Research reveals new insights into solidification cracking during welding of steel

New research led by our University has made a novel breakthrough in understanding how solidification cracking occurs during the welding of steel, an important engineering alloy.

In a new study, which has been published in the journal Scientific Reports from Nature Research, the team from our Department of Engineering propose 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.

Hong Dong, Professor of Materials Engineering and lead author on the paper, said: “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 per cent 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).”

The team used synchrotron X-ray beamline at the European Synchrotron Radiation Facility (ESRF) to observe the crack formation at the real time.

The study is part of the team’s international EU FP7 project 'Mintweld', working with eleven partner organisations from 7 EU countries.