The solidification sequence in an 18-8 stainless steel, investigated by directional solidification
- 350 Downloads
The directional solidification technique was applied in order to investigate the complicated solidification sequence in a commercial austenitic stainless steel which was known to yield a primary precipitation of § ferrite when cast into a 5 tons ingot. Three stages of solidification were found. The first precipitation of § ferrite was interrupted by precipitation of austenite and at the end of the solidification there was a transition back to precipitation of § ferrite. The competition between the first two stages is affected by the cooling rate and the nitrogen content. The precipitation of austenite from the melt results in the usual coring whereas ô ferrite forms with a very homogeneous composition, presumably due to rapid diffusion in this phase. On cooling austenite forms from the § ferrite and this reaction also results in coring, presumably due to rapid diffusion in § ferrite.
KeywordsFerrite Austenite Metallurgical Transaction Metallurgical Transaction Volume Solidification Front
Unable to display preview. Download preview PDF.
- 1.A. Hultgren:J. Iron Steel Inst., 1929, vol. 70, pp. 69–113.Google Scholar
- 3.G. Nygren: Internal Report, Avesta Jernverk AB.Google Scholar
- 4.M. Beckert and H. Klemm:Hanbuch der Metallographischen Atzverfahren D.V.G., Leipzig, 1966.Google Scholar
- 5.E. Scheil:Z. Metallk, 1942, vol. 34, pp. 70–72.Google Scholar
- 6.H. Fredriksson:Scand. J. Met, 1972, vol. 1, pp. 3–7.Google Scholar
- 7.J. W. Pugh and J. D. Nisbet:J. Metals, 1950, vol. 188, pp. 268–76.Google Scholar