Influence of Nickel on Abrasion and Erosion Wear Behavior of Thin and Thick Section Permanent Molded Austempered Ductile Iron for Wind Turbine Hubs

The influence of 2.0% nickel on thin and section permanent molded austempered ductile iron samples were investigated for abrasion and erosion behavior. The section sizes of samples were varied at two levels viz. 25 mm and 50 mm. Wind turbine hubs which were subjected to wear and erosion were made from thin and thick section PMADI castings. The austempering temperature and time were optimized for improved wear behavior and strength at 3000 C for 60 mins. Nickel additions showed about 7% improvement in the wear resistance of thin section PMADI samples over unalloyed PMADI samples. For the purpose of comparison, sand-cast austempered ductile iron was also evaluated for abrasion, erosion resistance. Thin section (25 mm) PMADI samples subjected to austempering at 3000 C for 60 mins showed improved abrasion and erosion behavior in addition to higher strength values over thick section (50 mm) PMADI and sand cast ADI samples. Further these data were analyzed with structure property correlation and were well supported by light photomicrographs.