ABSTRACT
The welding structure of the gear should focus on solving the following problems in heat treatment:
1. Mechanical properties of the welded HAZ zone decreased.
The content of high carbon martensite in the HAZ area increased after welding. In the welding process, it was difficult to be heated evenly, and the high temperature tempering zone would appear in the near-crack zone, which decreases the whole structure strength, thereby resulting in the brittleness and hardening of the gear. 2. Crack and deformation of the weld zone In the heating and cooling process of the welding structure of the gear, the thermal conductivity of different gear surfaces and internal temperatures changed to thermal expansion and contraction, and thermal stress could make the gear crack and lead to deformation.
