High Strength Stainless Steels: A Balance to Achieve Mechanical Properties and Stress Corrosion Resistance

Despite development of titanium in structural parts or in landing gear components, stainless steels with very high resistance appear as a necessary and complementary solution for some of those parts.

Aubert&Duval has developed and proposes now as a mature alloy the MLX17 (AMS5937) for various applications from structural parts to fastener, where corrosion resistance is of the utmost importance.

In order to extend the possibilities of this alloy family of precipitation hardening stainless steels, Aubert&Duval developed MLX19 grade (AMS 5955), aiming at keeping high corrosion resistance properties. Extensive work has been performed thanks to collaboration between Messier Bugatti Dowty and Aubert&Duval to develop experience, with more than 10 industrial heats, at the different steps of components manufacturing. Indeed these grades require specific and innovative processing solutions due to their metallurgical specificities. Through this work and process improvements that resulted, it is now possible to ensure the reliability of the materials keeping a high level of mechanical properties. Moreover comprehensive studies and comparison of stress corrosion assessment methods have been performed in order to characterize accurately performances in terms of stress corrosion cracking resistance.