In:
MRS Proceedings, Springer Science and Business Media LLC, Vol. 903 ( 2005)
Abstract:
Metastable austenitic stainless steels may transform to martensite when subjected to cold rolling. Upon subsequent annealing the martensite reverts back to ultra-fine grained austenite. Based on this concept, nano/submicron austenitic grains have been produced in a 63% cold rolled commercial AISI 301LN subjected to annealing treatments at 600°C, 800°C and 1000°C for 1, 10 and 100 seconds. Transmission Electron Microscopy (TEM) observations show the formation of equiaxed austenitic grains as small as ∼ 200nm in samples annealed at 800°C, and a dramatic increase in grain size as the annealing temperature and duration is increased. Additional tensile tests indicate that samples annealed at 800°C for 1 second exhibit a yield strength of ∼ 740 MPa and an total elongation of ∼ 45%. This combination of strength and ductility is excellent exceeding those of conventionally annealed steels (σ y =350 MPa; Ductility ∼ 40%) or cold-rolled steels (σ y =650 MPa; Ductility ∼ 30%). Finally, a correlation between the observed grain sizes and mechanical properties, in particular the yield strength, is obtained. Preliminary analysis indicates that the Hall-Petch equation can satisfactorily relate the observed yield strength with corresponding grain sizes.
Type of Medium:
Online Resource
ISSN:
0272-9172
,
1946-4274
DOI:
10.1557/PROC-0903-Z05-40
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2005