The fracture and plastic deformation of aluminum alloyed Hadfield steels

The plastic deformation and fracture behavior of Fe-Mn-Al-C cast Hadfield steels were studied. According to the Al, Mn and carbon contents, five different compositions of Hadfield steels were selected in order to study the orange-peel phenomenon, plastic deformation and fracture modes of the alloys using the tensile test. It is observed that Al addition increases the yield strength but decreases the ultimate tensile strength and the elongation. In addition, Al addition decreases or disappears the peeling of the surface and suppresses the twinning induced by plastic deformation. The fractographies of tensile specimens show that in the fractured surfaces of standard and 1.5% Al Hadfield steels, there are many secondary micro- or nano-dimples between the primary large dimples and shear rupture do not involve. But, the cleavage fractures with intergranular cracks appeared when more Al is added. (C) 2009 Elsevier B.V. All rights reserved.