Ball milling of stainless steel scrap chips to produce nanocrystalline powder

• Published in: Journal of materials science Vol. 42; no. 8; pp. 2844 - 2848
• Main Authors: Enayati, M. H, Bafandeh, M. R, Nosohian, S
• Format: Journal Article
• Language: English
• Published: Heidelberg Kluwer Academic Publishers-Plenum Publishers 01.04.2007; Springer; Springer Nature B.V
• Subjects: annealing; Austenite; Austenitic stainless steels; Ball milling; Chips; Cross-disciplinary physics: materials science; rheology; Deformation; electron microscopy; Exact sciences and technology; hardness; Heat treatment; Martensite; Martensitic transformations; Materials science; Microhardness; milling; Nanocrystals; Nanostructure; Other topics in materials science; Physics; powders; Scanning electron microscopy; Stainless steel; Stainless steels; Steel industry; Steel scrap; X-radiation; Powder metallurgy; Metal chip; Crushing; Stainless steels; Nanocrystal
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-006-1371-2

Nanocrystalline stainless steel powder was produced by ball milling of austenitic stainless steel scrap chips. The structural and morphological changes of samples during ball milling and after subsequent heat treatment were investigated by X-ray diffractometery, scanning electron microscopy and microhardness measurements. During ball milling the austenite in as-received chips partially transformed to the martensite phase with nanoscale size grains of ∼15 nm. This structure exhibited high microhardness value of about 850 Hv which is much higher than that for original samples. The deformation-induced martensite partially transformed to austenite after annealing at 700 °C for 1 h reducing the hardness of powder particles.