Laser welding of cast iron and carburized steel for differential gear
Jiyoung Yu, Taikmin Jung, Sulae Kim and Sehun Rhee*
The Journal of Mechanical Science and Technology, vol. 25, no. 11, pp.2887-2893, 2011
Abstract : This study concerned laser welding replacing the traditional bolted connection of the ring gear and differential case in the power train
of the automobile. Laser welding is necessary to reduce weight and manufacturing cost, since the bolted connection method requires
additional parts and space. In the differential gear, however, it is difficult to control the welding processes because cast iron and carburized
steel contain high carbon content. To solve these welding problems, laser welding using Ni-base filler metal was used in this work.
The results of welding with Ni-base filler metal satisfied the torsional stiffness and durability, but compared to the bolted connection
method, noise and hardness problems occurred. Therefore, to solve these problems, penetration depth was decrease from 5mm to 4mm
and the carburized layer of the ring gear was cut with 1mm. As well, numerical method was used to evaluate welding deformation, torsional
stiffness and fatigue.
Keyword : Carburized steel; Cast iron; Computer simulation; Differential gear; Laser welding |