Boron effects on the ductility of a nano-cluster-strengthened ferritic steel

Artikel i vetenskaplig tidskrift, 2011

The mechanical properties of Cu-rich nano-cluster-strengthened ferritic steels with and without boron doping were investigated. Tensile tests at room temperature in air showed that the B-doped ferritic steel has similar yield strength but a larger elongation than that without boron doping after extended aging at 500 degrees C. There are three mechanisms affecting the ductility and fracture of these steels: brittle cleavage fracture, week grain boundaries, and moisture-induced hydrogen embrittlement. Our study reveals that boron strengthens the grain boundary and suppresses the intergranular fracture. Furthermore, the moisture-induced embrittlement can be alleviated by surface coating with vacuum oil. (C) 2010 Elsevier B.V. All rights reserved.