抄録
The deoxidation of melts by carbon or hydrogen in vacuum has been studied to prepare tolerably pure iron and nickel or their alloys. The main results observed were, (1) as the smaller values of the product of oxygen and carbon contents in iron and nickel melts under high vacuum of 10−4 to 10−5 mmHg, [0.0006%]·[0.0005%] and [0.0001%]·[0.0001%] can be obtained respectively, (2) the deoxidation rate of iron melt by allowing hydrogen to flow is much smaller than that in nickel melt, and the flow rate measured by volume of hydrogen is more effective for the deoxidation rate than the flow rate measured by the PV-product of it, (3) the release of hydrogen from iron when chill-cast in a water-cooled copper mould in low pressure hydrogen is much quicker than that in nickel, (4) the grain size of ingots made by chill-casting becomes very large with the decrease of oxygen content of melts, in both iron and nickel, in the range of lower oxygen content. (5) The cold-workability of these ingots is so greatly improved with decrease of oxygen contents of the ingots, that the ingots containing little oxygen can be easily forged at the room temperature without pre-heating, particularly in the case of nickel ingots.
