About

This project targets an implementation and development of corrosion resistant high strength maraging steels for two applications, with two different strength levels, 1400 and 1900 MPa.

Macroscopically, this project aims to study the Process-Structure-Property (PSP) correlations of these novel high strength maraging steels with Ni-Ti-Al based intermetallic nanoprecipitation. These objectives will be realised via a combination of three waves of generic laboratory materials processing and two industrial trials.

Via the laboratory processing in combination with extensive dilatometry, the project aims at understanding the isolated effect of single intermetallic phases (mainly Ni₃Ti and NiAl) and other elements, e.g. Mo and Cr on strength and other properties e.g. toughness and/or corrosion.

The two industrial trials target improving processability and robustness.  A first aspect on this processability will look at the effect of recycling and scatter on properties.  A second aspect will focus on the influence of shaping via forging into complex parts with different thermomechanical processing paths (effect of massivity).

This project is highly differentiating and includes a wide socio-economic impact for several reasons. For the first time, an innovative sorting and recycling strategy, crucial for cost-effective industrialisation, has been applied on maraging steel.  Never before, such an extended and structured investigation has been done on all aspects of the “Process-Structure-Property” (PSP) correlation triangle in modern Co-free maraging steels.

The project has a double industrial valorisation track.

• In today’s aerospace application development, weight reduction – driven by reduced CO2 emissions – requires higher strength steels. These new materials should further be corrosion resistant as current protective coatings will be banned for environmental reasons. Therefore, taking the “stainless” landing gear to a higher strength level with sufficient robustness, is key for the future aerospace market. Furthermore, the use of high strength stainless grades over the currently applied titanium alloys has multiple strategic and environmental advantages: lower EU dependency on Ti-supply, clear cost advantage contributing to the EU competitiveness, recyclability, and lower energy consumption.
• The second valorisation track focusses on the development of lean maraging steels for stress corrosion cracking resistance. Additional advantages of maraging over regular high strength carbon steels are enhanced weldability and design freedom, as shaping can be done before the strengthening ageing treatment is applied.

 

The first 18 months of this project focused strongly on the synthesis of the different materials. Further in the project, the influence on basic and advanced properties will be evaluated.