Reparation of a Massive Machine Part Made of Grey Cast Iron

Abstract The analysis of the reparation procedure of the damaged turbine diaphragm from the ironworks plant, which was subjected to wear during the long-term exploitation process, is presented in this paper. The two-thirds of the bearing volume of the turbine diaphragm, made of grey cast iron EN-GJL-150, were damaged, and its functional properties were lost. The reparation was executed by the multi-layer hard-facing process. The procedure included verification of the material’s chemical composition, mechanical properties and metallographic structure, necessary for definition of the appropriate methodology for the part’s rehabilitation. The hard-facing was executed with preheating, as well as the post-welding heat treatment, with specifically selected filler materials and all the adequate welding process parameters. The executed hard-facing procedure turned out to be the cost efficient since, as a rule, the costs of reparation did not exceed 20 % of the price of that would be paid for acquiring the new part.