FRICTION WELDING OF HIGH-NB TIAL ALLOY AND 40CR STEEL RODS

Xin Wang, Minghao Liang, Dayong Lu

ABSTRACT:High-Nb TiAl alloy and 40Cr steel rods were welded together using friction welding method. The microstructure and microhardness distribution of the interface of the welded joint were investigated. The tensile strengths of the welded joints in as-welded and in annealing state were determined. The results indicated that the friction welding is an effective method for achieving the solid joint between high-Nb TiAl alloy and 40Cr steel. The tensile strength of as-welded joint reached about 150MPa, and fracture occurred at the interface. However, after annealing at 500°C for 10h, the tensile strength of the joint reached about 400MPa, and fracture occurred on the high-Nb TiAl alloy side. The microhardness at the welded interface was much higher than those of the 40Cr steel and high-Nb TiAl alloy in as-welded state.

Keywords:High-Nb TiAl alloy, 40Cr steel, friction welding, microstructure, mechanical properties