Effect of Heat Treating Regime on Mechanical Property and Microstructure of BT18Y Titanium Alloy

摘要

How heat treatment affect on mechanical property and microstructure of BT18Y titanium alloy were studied. 6 heat treating regime was selected. They are 900°C/3h, AC, 930°C/3h, AC; 950°C/3h, AC, 900°C/3h, AC+600°C/6h, AC, 930°C/3h, AC+600°C/6h, AC, 950°C/3h, AC+600°C/6h,AC. It is shown that alpha phase and transformed beta appear after heat treatment. And size of primary alpha phase is smaller after annealing than after duplex-annealing. At room temperature, tensile strength after annealing was lower than after duplex-annealing. On annealing, room temperature tensile strength increases with increasing heat treatment temperature. On duplexannealing, room temperature tensile strength reduces with increasing first heat treatment temperature. High temperature tensile strength is changed very slowly with changing heat treating regime. And strength difference is 30MPa. Impact-toughness on annealing is higher than on duplex-annealing. On annealing, impact toughness steeply increases with increasing heat treatment temperature. On duplexannealing,impact-toughness slowly increases with increasing first temperature.