Stress corrosion cracking of a wrought Mg–Mn alloy under plane strain and plane stress conditions

Stress corrosion crack growth of a rare earth containing Mg–Mn hot rolled alloy was studied using compact tension and circumferential notch tensile specimens employing constant load in 0.1 N NaCl solution saturated with Mg(OH)2. Circumferential notch tensile specimens satisfied plane strain conditions; Log crack velocity versus stress intensity plots yielded slope of 0.5 and 1 for stage I region and threshold stress intensity of 10 and 13 MPa m1/2 for circumferential notch tensile and compact tension specimens respectively. Fractography showed transgranular features involving hydrogen in stress corrosion cracking.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Stage I crack growth behaviour of hot rolled Mg–Mn alloy was studied. ► CNT and CT specimens were used in chloride containing solution at constant load. ► At crack velocity of 10−10 ms−1 the alloy exhibited KISCC/KQSCC as 10/13 MPa m1/2. ► CNT specimens did not exhibit stage II crack growth. ► Transgranular feature of fractography is attributed to hydrogen embrittlement.