Stress corrosion cracking of high-strength AZ31 processed by high-ratio differential speed rolling

Stress corrosion cracking (SCC) in distilled water was studied for AZ31, processed by differential-speed-rolling to different strengths, using Linear Increasing Stress Tests (LISTs). The stress corrosion crack velocity was 5.0 ± 2.5 × 10−9 m s−1, independent of applied stress rate and independent of material strength. SCC susceptibility was greater at lower applied stress rates manifest most importantly as a lower threshold stress for stress corrosion crack initiation. SCC susceptibility could be characterised by the ratio of threshold stress to yield stress, which was dependent on processing details and was as low as 0.3.