In order to investigate into the fact that, with various tool steels, the quenching-deformation is anisotropic against the rolling direction, some specimens were cut out from seven species of tool steel bars A (JIS SKD 1), B (SKD 2), C (SKD 12), D and E (SKS3), F (SKS 2) and G (SUJ 2) either in the longitudinal or in the transversal direction and subjected to quenching under various conditions. The change of length of the specimens then was measured with a Carl Zeiss U.M.M. and a Leitz dilatometer as well as the hardness and the structure were observed. The results obtained were as follows: (1) In the case of quenching specimens of the first group (steel A & B), the linear expansion of the longitudinal specimens was larger than that of the transversal specimens, while if a contraction occurred owing to quenching, the linear contraction of the longitudinal specimens was less than that of the transversal ones. On the contrary, in the case of quenching specimens of the second group (steel C, D, E, F & G), linear expansion of the longitudinal specimens was less than that of the transverse specimens, while if a contraction occurred also due to quenching, the linear contraction of the longitudinal specimens was larger than that of the transversal ones. Namely, the behavior of deformation was found to be opposite in the two groups. (2) After investigation into the experimental results of dilatometric and structural observations with steels A & D, the cause of deformations described above was made clear.
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