Details

Autor(en) / Beteiligte

• Liu, L
• Yu, Qin
• Wang, Z
• Ell, Jon
• Huang, M X
• Ritchie, Robert O

Titel

Making ultrastrong steel tough by grain-boundary delamination

Ist Teil von

• Science (American Association for the Advancement of Science), 2020-06, Vol.368 (6497), p.1347-1352

Ort / Verlag

United States: The American Association for the Advancement of Science

Erscheinungsjahr

2020

Quelle

American Association for the Advancement of Science

Beschreibungen/Notizen

• Developing ultrahigh strength steels that are ductile, fracture resistant, and cost-effective would be attractive for a variety of structural applications. We show that improved fracture resistance in a steel with an ultrahigh yield strength of nearly 2GPa can be achieved by activating delamination toughening coupled with transformation induced plasticity. Delamination toughening associated with intensive but controlled cracking at Mn-enriched prior-austenite grain boundaries normal to the primary fracture surface dramatically improves the overall fracture resistance. As a result, fracture under plane-strain conditions is automatically transformed into a series of fracture processes in "parallel" plane-stress conditions through the thickness. The present "high-strength induced multi-delamination" strategy offers a different pathway to develop engineering materials with ultra-high strength and superior toughness at economical materials cost.