EBW bronze to CI and visual cracks 1

[Alan11]

Hi all,
please help, we have observed small cracks, radial and longitudual in the welds on some products. My first guess was press fit stresses between the 2 components, but does anyone have any experience of the causes of such cracks by the EBW itself. I wanted some background info before I send them away for analysis which is very expensive. We don't have any criteria for judging these. I might surface grind them to try to understand the depth. Anyone with any thoughts much appreciated
thanks
alan

 

[metengr]

Alan11;
Look at the bronze composition - should be similar to a phosphor bronze casting. Next look at joint design. Cracks of this type most likely would originate from shrinkage stresses with an improper joint design. Joint design is critical for EB welding. Otherwise, solidification cracks can occur within the weld region.