Roll grinding efficiency boosted with Norton products

Both wheel types are engineered with a vitreous bond structure, resulting in free-cutting grinding. This maximises metal removal rate, while drawing low power from the machine tool and generating minimal heat, consequently avoiding metallurgical damage. Tests were carried out at Saint-Gobain Abrasives' research and development centre with a 915 mm diameter by 76 mm wide Quantum wheel on an 80 kW grinding machine. It processed a range of four different work roll and back-up roll materials – ICDP (indefinite chilled double poured) cast iron, high-chrome cast iron, CPC (continuous pouring process for cladding) high speed steel, and (HSS) standard high speed steel – all for hot rolling mills. Surface finish achieved was between a half and one micron. Results on ICDP were astonishing, says Saint Gobain. Compared with the next best ceramic grinding wheel, Quantum had a 60% higher grinding ratio, or G ratio, which is the amount in grams of metal removed per gram of wheel consumed. Compared with the worst wheel, Quantum performance was 140%. When processing a CPC HSS roll, the G ratio of the Saint-Gobain Abrasives product was around 60% better than all the other ceramic grain wheels benchmarked. Chrome-iron and HSS roll grinding showed a smaller, but still appreciable increase in wheel longevity. Across all the trials, the manufacturer claims an average increase in wheel life of 35%. Another test showed a rise in metal removal rate using Quantum of over 60% - from a Q of 2.3 up to 3.7 mm3/s/mm - while the power drawn from the grinder was 20% less. Vortex aluminium oxide grinding wheels have also proved effective at processing most rolls, but not work rolls, as used in hot rolling mills. The abrasive wheels cost less than Quantum and offer a proportionately lower G ratio. Nevertheless, Vortex performance in roll grinding is still very high, it is claimed.