ODS ferritic steels produced by an alternative route (STARS): microstructural characterisation after atomisation, HIPping and heat treatments. (19th October 2016)

• Record Type: Journal Article
• Authors: Gil, E.; Ordás, N.; García-Rosales, C.; Iturriza, I.
• Is Part Of: Powder metallurgy. Volume 59:Number 5(2016)
• Page Start: 359
• Page End: 369
• Publication Date: 2016-10-19
• Subjects: ODS Ferritic Steel -- Mechanical alloying -- Y–Ti–O nanoparticles -- Gas atomisation alternative route -- Hot isostatic pressing -- Heat Treatment -- Microstructural Characterisation -- Prior Particle Boundaries (PPBs) -- Thermal Induced Porosity; Powder metallurgy -- Periodicals; 671.3705
• DOI: 10.1080/00325899.2016.1254894
• Languages: English
• ISSNs: 0032-5899

Abstract

Abstract : The conventional PM ODS Ferritic Steel (FS) processing route includes gas atomisation of steel powder and its mechanical alloying (MA) with Y2 O3 powder particles to dissolve yttrium and form, during consolidation, a dispersion of oxide nanoparticles (Y–Ti–O) in a nanostructured matrix. This work presents an alternative route to produce ODS steels avoiding MA: STARS (Surface Treatment of gas Atomized powder followed by Reactive Synthesis). STARS FS powders with composition Fe–14Cr–2W–0.3Ti–0.23Y, already containing the nanoparticles precursors, were gas-atomized. Oxygen, Y and Ti contents were tailored to the required values to form Y–Ti–O nanoparticles during processing. Powders were HIPped at 900, 1220 and 1300°C. Specimens HIPped at 900 and 1220°C were heat treated (HT) at temperatures ranging from 1200 to 1320°C. The microstructural evolution with HIP and HT temperatures, including characterisation of nanoparticles and feasibility of achieving complete dissolution of prior particle boundaries (PPBs) were assessed.