Maraging steels are widely used in aeronautic for structural parts, like landing gears, flap tracks or engine pylons. Key mechanical characteristics are high strength and good fracture toughness. In recent years aeronautical suppliers are seeking for more information about stress corrosion cracking of these alloys, which could become a key characteristic for maraging steel in the future.
Stress corrosion cracking is traditionally characterized in 3.5% NaCl with a constant loading or with “homemade” tests. It is then necessary to realize tests at different loadings with duration up to 1000h, so these methods are relatively expensive and very time consuming. In 2000’s, Rising Step Loading (RSL) method had been developed. It allowed to realize stress corrosion cracking (SCC) tests in few days and appears to be a solution to quickly characterize steels.
Aubert & Duval decided to develop his own test machine for RSL tests in partnership with Polytech Clermont. This project has been accomplished by students of this engineering school, who have developed design and built two tests machines. The first machine is dedicated to pre-cracking of test specimens and the second one to RSL tests.
These test machines will allow a quick assessment of the critical stress intensity factor for stress corrosion KISCC with different applied potential to characterize resistance of maraging steel to H-embrittlement or anodic dissolution.