Experimental study of the strain-strengthening effect on the mixed mode notch-crack fatigue propagation in austenitic stainless steel 06Cr19Ni10

• Upon initiating from the crack tip, the mixed mode crack changed to Mode I.
• The strain-strengthening factor has no effects on the crack growth path.
• Strain-strengthening can slow down the crack growth rates in some extent.
• Crack growth rates with different strain-strengthening levels are formulated.
• Martensite transformed increases with increasing strain-strengthening level.

Experimental studies on I + II mixed mode notch-crack fatigue propagation in austenitic stainless steel 06Cr19Ni10 were carried out with consideration of the strain-strengthening effects. It is found that after initiating from the notch-crack tip, the new crack changes from I + II mixed mode to Mode I. Strain-strengthening has no effects on the crack growth path, but has some effects on the crack growth rates. Microstructure analysis indicates that total volume fraction of martensite transformed from the original austenitic microstructure increases with increasing the strain-strengthening. However, the moderate volume fraction of martensitic transformation seems more beneficial to reduce the crack growth rate.