ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The nickel-free austenitic stainless steel produced by solution nitriding (Fe-25%Cr-1%Nalloy) was subjected to isothermal heat treatment, and then the microstructure formed through thedecomposition of austenite was investigated in terms of the morphology of eutectoid structure andthe size of eutectoid block. On the isothermal heat treatment at 873K~1223K for thesolution-nitrided steel, the austenite decomposed to eutectoid structure composed of ferrite andCr2N nitride. This transformation could be completely finished after long time heat treatment in theabove temperature range. The nose temperature of T.T.T. curve was around 1173K, and the time tostart the eutectoid transformation was only 100~200s. The eutectoid structure was formed mainlyalong austenite grain boundaries and then grew into the untransformed austenite region. Finally, theaustenite was completely decomposed into ferrite and Cr2N nitride. As a result of OIM observationfor the specimen after isothermal heat treatment, the eutectoid structure was found to be dividedinto small-sized ferrite blocks, in which lamellar Cr2N plates were finely distributed. The block sizeand the mean ferrite path of eutectoid structure were decreased with lowering the heat treatmenttemperature. In the 873K heat-treated material, these values were estimated at 20 microns and 0.1microns, respectively
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/15/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.539-543.4950.pdf
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