On methods of testing technological plasticity of steels

The results of testing technological plasticity of steels vary depending on the size of the specimen and test atmosphere. This is explained by the effect of the oxidation processes and dimensional factor. The most sensitive to the test atmosphere are the specimens of 5 mm in diameter. Plasticity of the specimens, 8 mm in diameter, does not practically change at a temperature of 800-1000 deg C. The slight tendency towards the increase of plasticity is displayed by the specimens, 8 mm in diameter, at a temperature of 1250 and 1300 deg C. The plastic properties of the steels are best of all revealed when conducting tests on the specimens of 8 mm in diameter and particularly 5 mm in diameter at 1250-1300 deg C in the argon medium. When carrying out the high-temperature torsion tests, the specimens should be protected by neutral atmosphere from the detrimental effect of the surrounding medium