Crucible steel

Common card · No. 207926

Crucible steel is steel made by melting pig iron, cast iron, iron, and sometimes steel, often along with sand, glass, ashes, and other fluxes, in a crucible. Crucible steel was first developed in the middle of the 1st millennium BCE in Southern India and Sri Lanka using the wootz process. In pre-industrial times, it was not possible to produce sufficient temperatures with charcoal or coal fires required to melt iron or steel. However, pig iron, having a higher net alloy content and thus a lower melting point, could be melted. This is due to the effect of freezing-point depression. By co-heating wrought iron or steel with pig-iron for a long time, Carbon content in the pig iron could be reduced as it slowly diffused into the iron. In addition, H2O containing organic materials could be mixed into fluxing agents. Oxygen reacted with excess phosphorus, sulfur, and silicon typical of pig iron producing additional heat and low density slag. The additional heat was sufficient to dissolve some...

Read on Wikipedia · Image Rahil Alipour Ata Abadi, GFDL