Batch Optimization of Process Parameters for Hot Working of High Nitrogen Stainless Steels and Thermodynamic Validation

Descrizione del progetto

Modelli per aiutare l’industria a sfruttare spiragli di opportunità alle alte temperature

Usato per la prima volta come elemento di lega negli anni Trenta, l’uso dell’azoto come lega dell’acciaio inossidabile è diventato un’importante area di ricerca e sviluppo negli anni Ottanta e Novanta. I progressi nella modellizzazione e nella lavorazione hanno portato a un crescente sfruttamento dell’alta resistenza e dell’eccellente resistenza alla corrosione degli acciai inossidabili ad alto tenore di azoto in ambienti estremi. Migliorarne le proprietà e al contempo ridurre l’impatto ambientale e aumentare la sostenibilità della lavorazione richiederà l’impiego di modelli di processo migliori. Il progetto BOHNS-TV, finanziato dall’UE, lavorerà sull’ottimizzazione della lavorazione a lotti degli acciai inossidabili ad alto tenore di azoto attraverso una serie completa di esperimenti e la modellizzazione.

Obiettivo

High nitrogen stainless steels are becoming an increasingly important new class of engineering materials due to its favorable combination of mechanical, chemical and physical properties: high strength and toughness, nickel-saving and excellent corrosion, which enable its application in extensive fields such as military, marine equipment, petrochemical, etc. Hot working of high nitrogen stainless steel is always the challenge to engineers and researchers due to the diversity of the hot working window, which is strongly affected by nitrogen content. Moreover, there are still open questions on nitrogen content effect on thermodynamic theories (e.g. dynamic recrystallization and stacking fault energy). The primary objective of this project is to develop a novel approach for batch optimization of hot working processes of high nitrogen stainless steels, validate the thermodynamic theories and transfer scientific results into application. A gradient model will be synthesized using chemical heat treatment to support the modelling and experiments in a mechanical processing area. Both modelling and experimental studies will be carried out in close collaboration with Sandvik (a world-leading manufacturer of stainless steel) and KTH, Royal Institute of Technology, Sweden (one of the world-leading universities on first-principles study of the stacking fault energies in advanced alloys). These international collaborations help to ensure that the project will be successfully completed and the findings of the project will be transferred to and implemented in industry. In broader terms, the project will contribute to the enhancement of traditional nitrogen alloying theory and improvement of manufacturing capacities of high nitrogen stainless steel, reducing the energy consumption and emission pollution, and thus helping to attain socioeconomic and environmental targets in the context of the EU 2020 vision.