51 - Fatigue Resistance of Weld Repaired Ductile Iron Castings

Abstract:

Sometimes casting suppliers find that a casting has imperfections, such as pores, in an area of the casting that the customer has indicated is critical to its performance. This indication of criticality may be due to cyclic stress loading that can cause the growth of a fatigue crack. Welding repair is widely used for cosmetic repairs or repairs in non-critical areas. But in the critical areas, the resistance of the welds to fatigue cracking may be considered unacceptable without data and require replacement of the casting. This possibility may prevent clients from choosing ductile iron, choosing instead steel casting or plate solutions. An understanding of the fatigue performance of welds in ductile iron castings would allow the critical regions to be judged to determine if repairs can be performed which will meet the criteria for performance in the critical area.