2013

Auerkari, Pertti; Salonen, Jorma; Pohja, Rami; Nevasmaa, Pekka; Yli-Olli, Sanni

Mineral wool fibre is produced from a melt stream by spinning wheels that are eroded by abrasive fibre particles at locations where the wheel rim is not protected by a solidified melt layer. Erosion of the A430 overlay weld of the rim requires relatively frequent overlay replacement, while productivity (rotation speed) is also limited by the base materials strength. This work aimed to propose alternative materials to extend the lifetime and production capacity of the (3rd) spinning wheel. For this purpose a new and used 3rd spinning wheel rims were provided to VTT by the customer. A microstructural evaluation was performed to assess the temperature distribution across the rim in the regions of heavy erosion and hot spot below the mineral deposit. The results suggest a peak surface temperature of about 930°C at the deposit-covered hot spot surface, but probably about 850°C or less on the surface suffering highest rate of erosion.