fusion ratio

1. In the field of welding, the fusion ratio refers to the volume percentage of the base material that is melted during welding, as part of the weld metal. The fusion ratio can also be calculated as the ratio of the cross-sectional area SB of the base metal that has melted in the weld metal to the total cross-sectional area SA+SB of the entire weld, that is: Fusion ratio = SB/(SA+SB). 2. When the shape of the groove and the molten pool changes, the fusion ratio also changes; for example, when a groove is created in the weldment, the fusion ratio decreases significantly compared to when no groove is used. When arc welding carbon steel, alloy steel, and non-ferrous metals, the chemical composition of the weld is often adjusted by changing the fusion ratio, in order to reduce sensitivity to welding cracks and improve the mechanical properties of the weld metal.

Is it better to have a larger fusion ratio, or a smaller one?

A large fusion ratio is not good, and a small one is also not good. If it is too large, it will result in excessive heat input and waste of material. If it is too small, it will result in substandard performance. As long as the performance is satisfactory, the fusion ratio can be within a certain range.