Sustainable trunnion mounting on steel and pig iron ladles

Even without lubrication a newly developed heat-treatable / hardened manganese steel tribological pairing will as a trunnion mounting on heavy duty steel and pig iron casting ladles achieve a service life of at least 10 to 12 years, whereas the average service life of conventional tribological pairings made of ferritic steel and miscellaneous copper alloys or other steel matrices is only 0.4 to 0.8 years despite intensive periodic lubrication. The new pairing makes it possible to significantly reduce the lubrication or render it unnecessary. The article describes operating results from the re-equipment of Hüttenwerke Krupp Mannesmann GmbH in 1999/2000 with 26 steel and mixing ladles of the latest generation and apayload of 375 t. At the steelworks of Salzgitter Flachstahl in Germany the bearing arrangement was adapted to the existing 250-t vessels. The findings from theory and experiment are confirmed by the many years' experience available today on the whole. In addition to significant savings in costs and resources, the new steel friction bearing leads to a considerable environmental protection. The operational reliability will also undergo a sustainable increase.