Corrosion fatigue crack propagation testing with the KRAK-GAGE® in salt water

The application of a relatively new, thin-film bondable transducer, commercially available under the name KRAK-GAGE®2, was evaluated for corrosion fatigue crack propagation tests in a sea water (3.5%NaCl) environment at ambient temperature on an HY 80 steel. Fatigue crack growth data generated by this method are shown to be consistent with those obtained by the compliance method and the commonly used optical/visual measurements. Thus, this new instrumentation system appears to be a valuable addition for corrosion fatigue crack growth testing. Furthermore, test data acquisition and analysis of the KRAK-GAGE and the compliance method were computer automated, which results in considerable cost savings for such customarily labor intensive fatigue crack propagation experiments. Additionally, the FRAC-TOMAT/KRAK-GAGE instrumentation system can be utilized for direct test machine control, permitting completely automated fatigue crack growth testing.