The medium carbon alloy steel Cr-Ni-Mo was melted by a 50 kg vacuum induction furnace
and the mechanical properties of test steel-maximum load and reduction of area at 600~1400 ℃ have been measured by Gleeble-3800 test machine. The test results showed that brittle region(reduction of area ≤60%)of the medium carbon Cr-Ni-Mo steel was 910~700 ℃ and its plastic region was 1320~910 ℃.Its cast billet shouldn't be straightened at 910~700 ℃ in order to decrease cast billet crack.