Four approaches were comparatively investigated to determine the beta transus temperature of BT25 titanium alloy,including the method of calculation,thermal expansion,differential scanning calorimetry(DSC) and metallographic observation.The calculated beta transus temperature is 1023 ℃ and the results acquired using both methods of thermal expansion and DSC are 1029.2 ℃ and 1029.85 ℃,respectively.The transus temperature is 1029 ℃ by means of metallographic observation.It is found that the calculated tempera...