Abstract
The brittleness of steel at high temperature is very important for forging or hot working of steel. We dertermined the elongation of various carbon steels between 700° and 1050° and from these results we discussed the brittleness of steel at high temperature. All the samples of steel except the Armco iron showed two kinds of brittleness in the experimental temperature range. The first appears over the A1 transformation point. The reason seems to be in the coexistence of the two solid solutions α and γ. The second brittleness appears at a higher temperature and the minimun elongation occurs at about 850°. This is probably caused by the recrystallization of austenite and precipitation Al nitrides.
