Real temperature equilibrium within specimens is the basis of reliable results of hot tensile tests. These tests were undertaken with cylindrical specimens of a ferritic stainless steel AISI 430 and an austenitic stainless steel AISI 304. The specimens with diameters of 10,15, 20 and 25 mm were partially melted. The cooling rates after holding by a maximum temperature varied between 0.5 and 3.0 K/s. Temperature was measured continuously at the specimen center and 3 mm under the specimen surface during the whole test process. Tests with the smallest specimen diameter and under a slow cooling rate of 0.5 K/s had even temperature distribution in the radial direc-tion of the specimen so that no duration time is required at any test temperature. Such identical temperature distribution in the cross-section of specimens were changed in different ranges when the specimen diameter was enlarged or the cooling rate was increased. The necessary duration time for the temperature equilibrium in the radial direction of specimens is explained in detail in this study that can help the reliability of hot tensile test.
展开▼
