| Research Abstract |
1. Improving of the rolling mill reliability
The 4 high mill with 30mm work roll diameter, which composes a specific designed device, has already been developed to realize a heavy draft rolling, which is now under applying for a patent. Now, in order to increase a roll force when using the SiAlON roll, an improvement in the relative strength of the axis part, through changing a work roll position, has been planned.
2. Research on the rolling process tribology under vacuum conditions
(1) Vacuum and non-lubricant cold rolling and warm rolling; As the results of rollings of such metals as SUS 304, SUS 430, Ti, Cu, Al under the conditions of non-lubricant cold rolling with using SKD61 rolls, a rolling load increases in all cases under the conditions that the degree of vacuum is high, and this tendency becomes more and more conspicuous as the draft increases. In the case of rolling under the conditions ofnon-lubricant warm rolling, the results of rollings of the SUS 304 and the Ti show a contr
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ary tendency, but those of rollings of other materials show little changes.
(2) Vacuum and lubricant cold rolling and warm rolling; The rolling lubricity of PFPE (perfluoropolyethers), which has a low steam pressure of 5 X 10^<-13> torr at the room temperature, is superior in comparison with the lubricity of an oil the market used for each metal. In the case of cold rolling of a metal, there is a tendency that the rolling load generally increases as the degree of vacuum increases. However, in the case of cold rolling of the Al, there show little change in the rolling load. In the case of warm rolling pfthe SUS 304 and the Ti, a contrary phenomenon to the said tendency is shown.
(3) Rolling behavior of the SiAlON roll; Both the cold rolling and the hot rolling were carried out under a vacuum condition on the SUS 304 and the Ti, with using two kinds of rolls, that is, the SKD61 roll and the SiAlON roll. From these results obtained, it has been confirmed that, when using the SiAlON roll, the rolling load is greatly reduced especially in the case of hot rolling. In general, the surface of rolled sheet after rolling is rough and its brightness decreases thereby.
Through the results obtained as described in the above (l), (2) and (3), these subjects such as a process of an adhesion to the roll surface, a process of the roll coating, an analysis of changing of the sheet / roll surface properties, an effect of material's properties and so, are now continuously being investigated.
3. Characteristics of the cutting working of TiAl intermetallic compounds:
Vertical-milling and face-milling were carried out on a material of Ti-47at % Al-3at % Cr to investigate a damage on the tool and an accuracy of the processing working. From these results obtained, it has been cleared that this material has a high cutting-resistance property, and its tool life is short due to an adhesive stripping. Less
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