Masood Shah

Abstract

Investigation of crack propagation in X38CrMoV5 tool steel at room temperature and 600°C on small scale specimens

Masood Shah - 9 November 2010

Forging and high pressure die casting processes impose heavy mechanical loads on die materials and tools damaging their surface during production. This study proposes a novel method of characterisation of the surface damage of tool steels using thin specimens. Fatigue crack propagation experiments are carried out on the tool steel X38CrMoV5 at ambient temperature as well as at 600°C. The effect of specimen thickness, load ratio and temperature on the fatigue crack propagation is studied.
Different fatigue crack propagation parameters are established using numerical simulations. A method of crack tip opening displacement measurement is developed. This method is based on image acquisition with the help of a digital camera and a long distance microscope followed by an image correlation procedure, to measure the crack opening displacements. A fatigue crack propagation model based on crack opening displacement is developed and compared with traditional propagation models.

Keywords: Crack propagation, Fatigue, Tool steels, CTOD, Image correlation, J integral, Stress intensity factor, Rupture

Last modified: 04/24/2011 09:37 AM