Effect of solution aging heat treatment on microstructure and properties of Ti-6Al-4V-1Mo-1Zr alloy for drill pipe
The impact of solution and aging heat treatment process on the microstructure and mechanical properties of Ti-6Al-4V-1 Mo-1Zr alloy for drill pipes were studied by mechanical property test and microstructure observation.The results show that after solution aging in two-phase region,the experimental materials with duplex microstructure can be obtained;the volume fraction of primary αphase is decreased with increasing solution temperature,while the size and volume fraction of the β transition structure and secondaryα phase is increased with increasing solution temperature.After solution aging above the phase transformation temperature,the ex-perimental materials with lamellar microstructure can be obtained,as result of which the crack path is deflected during the fracture process.This has improved the crack propagation path,increased the energy absorbed by titanium alloy in the impact process,and enhanced the impact toughness of titanium alloy.The titanium alloy after TSSA treatment has the yield strength over 932 MPa,the elongation of 14.1%,and the impact energy greater than 45J,demonstrating ideal strength and toughness matching properties.
oil drill pipeTi-6Al-4V-1 Mo-1 Zr titanium alloysolution agingmicrostructuremechanical propertiesimpact energy