| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
This research project was aimed to obtain a basic understanding of the micristructural characteristics of the sheets which will be produced by the thin stripcontinuous casting process in near future. That is, to make clear the as solidified microstructure and structural change by the following phase transformationin solid. Single roll method was mainly used to make samples of Fe-Cr-Ni alloys. The main results obtained were as follows.
1.3%Cr addition was necessary to obtain ribbons of good shape condition.
2.There was a good correspondence between the texture and microstructure of ribbons.
3.The thickness of ribbon is proportional to -0.6th power of the roll surface velocity.
4.The as solidified phase was either single <alpha> phase, or (<alpha>+<gamma>) two phases, or single <gamma> phase. The (<alpha>+<gamma>) two phases region locate at the Cr rich side of the valley of liquides plane.
5.The fraction of <alpha> and <gamma> phases change drastically in a very narrow composition range. Especially, for the ribbons with 30 microns thick, the dominant phase changes by the 0.2wt% change in composition.
6.The eutectic solidification could not observed for the thin ribbons.
7.The grain size of as solidified specimen did not change largely by composition when the ribbon thickness was large. When the ribbon thickness is small, thesmallest grain size could be obtained when the composition is near two phases region.
8.When the ribbon thickness is small, the competitive solidification, at whichthe nucleus of both <alpha> and <gamma> with same composition form, can occur.
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