Effects of triple heat treatment on stress relaxation resistance of BT20 alloy

The BT20 alloy was treated by triple heat treatment as follows: quenching at 1020 °C with water cooling followed by aging at 750 °C for 100 min and aging at 550 °C for 2 h. And basketweave microstructure was obtained, which shows random relative orientation between α and β phase. BT20 alloy treated with “Triple heat treatment” shows higher stress relaxation resistance than that in equiaxed and widmenstaten microstructure.