Experimental and Simulation Study of Film Crack on Zinc-Coated 2Cr13 Steel Cables

Abstract

An experimental and simulation study on mechanical properties and cracking behavior of zinc film on 2Cr13 steel is carried out. The three-point bend with the acoustic emission technique and uniaxial tension tests were innovatively conducted to study the film fracture toughness and the critical thickness of zinc film at different strains. Meanwhile, simulations were made to analyze the influence of different factors on the dimensionless energy release rate of a surface crack and the stress field around the crack tip with the extended finite-element method. Results indicate that the film will not crack until the film thickness reaches the critical thickness, which decreases with the increase of tensile strain. The elastic modulus ratio, the thickness ratio, and the crack spacing have great impacts on the crack energy release rate and substrate stresses around the crack tip. Also, if the substrate stiffness is greater than the film stiffness for a given film thickness, the substrate thickness and the crack spacing are greater when the crack propagation is in a steady state.