Stress corrosion cracking

Maraging steel

Metallurgy

Materials science

Misorientation

Artificial seawater

Grain boundary

Geology

Oceanography

Physical chemistry

Cathodic protection

Hydrogen embrittlement

Hydrogen

Organic chemistry

Intergranular corrosion

Embrittlement

Cracking

Microstructure

Composite material

Corrosion

Chemistry

Electrode

Anode

Seawater

Corrosion Science

The effect of cathodic polarisation on stress corrosion cracking (SCC) behaviour of peak-aged Ni(Fe, Al)-maraging steel in artificial seawater was investigated. The steel shows better compatibility of strength and hydrogen embrittlement (HE) resistance than reported 18Ni-type maraging steels when potential is above −850 mV. This advantage stems from the abundant and evenly dispersed Ni(Fe, Al) nanoprecipitates. SCC occurs above −850 mV in a transgranular/intergranular-mixed manner involving a mechanics-dominant-anodic-dissolution-promoted mechanism and below −850 mV in an intergranular manner along parent austenite grain boundaries involving HE. For interpreting the HE mechanism, a novel model is proposed based on hydrogen-weakening interatomic bonds.

Effect of cathodic polarisation on stress corrosion cracking behaviour of a Ni(Fe, Al)-maraging steel in artificial seawater