The effect on Ba, Ca and Sr ladle inoculation in grey iron of variations in S content (0.02-0.10%), Al content (0.001-0.010%) and carbon equivalent (CE) (3.5-4.0%)was studied. Chilling properties were measured in a large range of cooling modulus wedge samples (0.1-0.5 cm). Sulphur content has a particularly large influence on chilling behaviour. The difference between the inoculation performance of Ba, Ca and Sr alloy became more pronounced as cooling rate increased. As a general rule, the graphitising efficiency of the three inoculating elements is in the order Ba <= Ca < Sr. It was found that Ba and Ca show an appropriate effect only in the most favourable conditions (high CE, high S, high Al), whereas Sr is significantly more effective in all experimental conditions. For thin wall grey iron castings, 0.07-0.10%S, 0.005-0.010%Al, 3.8-4.0% CE and Sr-FeSi inoculation are recommended.
