Determination of phase transformation point of TA24 alloy by composition calculating method and differential scanning calorimetry
LI Chunhui1, ZHANG Congyi1, WANG Shuo1, CHEN Jieming1, LIU Pan1,2,3, ZHANG Xinyao1,3,4
1. Luoyang Ship Material Research Institute, Luoyang 471023, China; 2. National New Material Production and Application Demonstration Platform (Advanced Marine Engineering and High-tech Ship Materials), Luoyang 471023, China; 3. State Key Laboratory for Marine Corrosion and Protection, Luoyang 471023, China; 4. Henan Key Laboratory of Technology and Application of Structural Materials for Ship and Marine Equipment, Luoyang 471023, China
Abstract:The β transformation temperatures of 11 pieces of TA24 near α titanium alloy samples in 4 specifications were measured by composition calculating method and differential scanning calorimetry. In the composition calculating method, the β transformation temperature of titanium alloy was determined according to the contribution rate of alloying elements and impurity elements to the phase transformation temperature. In the differential scanning calorimetry, the β transformation temperature was measured based on the heat change of titanium alloy during phase transition. The results showed that under the condition of 95% confidence, the deviation between methods was (-1.3±5.8) ℃, and the absolute value of deviation was (2.4 ± 3.9) ℃. The measurement results of composition calculating method and differential scanning calorimetry method were consistent, and the deviation was between -6.9 ℃ and 2.4 ℃, which were both less than the allowable deviation (±8 ℃) of two parallel tests in the laboratory specified by HB 6623.1-1992 and HB 6623.2-1992. The composition calculating method could be used as a convenient and effective method to quickly predict the β transformation temperature of TA24 titanium alloy.