鍛造用型鋼に關する研究
1951 年 37 巻 5 号 p. 291-301
詳細
1951 年 37 巻 5 号 p. 291-301
The authors have tried to get the relation between mechanical properties of some alloy steels, such as Ni-Cr-Mo, Mn-Cr-Mo, Cr-Mn or Cr-V, and the practical applicability for the forging die block, but they have failed to find the exact relation between them. Then, for this purpose, they have devised. the special testing machine, which shows the relation between the number of blows of small hammer striken on the cylindrical specimen and accumulated infinitesimal deformations of that specimen induced by the blows under high temperature condition. The accumulated deformations are measured with the micrometer.
As the testing condition above mentioned and the actual condition of die block under application are so similar that some exact relation between the results obtained by that testing machine and the endurance of die block must exist
The results are as follows:
1) Above 600°C substitute steels (Cr-Mn, Cr-V, etc.) show the abrupt increase of deformation, but at lower temperature than 600°C the deformatioon of Cr-Mn steel is less than that of Ni-Cr-Mo steel. (by the testing machine.)
2) In the case of the deep impression or the large die, the life of Cr-Mn die is shorter than that of Ni-Cr-Mo die. Nevertheless, in other case, the endurance of Ni-Cr-Mo die is not always longer than the others. (by the results of actual measurements of forging dies under application.)
3) As we know, in the former case, the temperature of some portion of die often becomes several hundreds degrees, we can recognize that good correlation exists between the results by the laboratory testing machine and the life of die block.
4) The mechanical test of the actual die block are also performed.
