Assessing the impact of carbonitriding on residual weld hydrogen in the manufacture of a gear component

In this paper, we report on the direct measurement of hydrogen flux from a machined car gear component immediately following carbonitriding treatment and prior to its welding to the gear train. Carbonitriding is a thermochemical process by which carbon and nitrogen are purposely introduced into the surface of steel components leading to an improvement of their wear and fatigue performance. Hydrogen bearing gases used in the treatment also cause hydrogen uptake in the steel. This hydrogen is subs