抄録
In the report I, the author has described the influence of C, Si, Mn, P and S. In the present report, he complements the first report with some additional experimental data, and then describes the influence of Cu and Al.
First, another method of testing the hot-tearing tendency is explained. This method, which the author calls test of "C" type, is used in the present study together with two methods already described in report I.
The results obtained are briefly summarized as follows:
(1) Increase in carbon does not increase hot-tearing tendency in the test of "C" type, while it increases hot-tearing tendency decidedly in the test of "A" type; the influence of carbon on hot-tearing tendency seems to vary, as some other investigators pointed out, with varying types of casting tested.
(2) It is quite sure that increasing copper content to 1.5% does not increase hot-tearing tendency in the wide range of sulphur content of 0.01-0.06%.
(3) Increasing aluminium up to 1% does not affect the hot-tearing tendency of low-sulphur steel containing about 0.01% sulphur.
(4) In high-sulphur steel containing about 0.03% sulphur, addition of 0.1-0.2% aluminium decreases the hot-tearing tendency.
