|After the steel has been poured, the crucible is replaced in the furnace and another charge of raw steel is added for melting. Most of the crucibles can be re-used for three melts before becoming too weak, when they are thrown away.
The crucible steel process was developed by Bejamin Huntsman in great secrecy. Many attempts were made by rival businesses to discover Huntsman's secret process. One story about these attempts involves an iron founder called Walker who had a foundry at Grenoside, on the northern outskirts of Sheffield.
It has been written that Walker disguised himself as a tramp and arrived outside Huntsman's works pretending to be ill. It was a very cold night and snow was falling. Walker pleaded with the workers to let him in so that he could warm himself.
The workmen allowed the beggar to take shelter and sleep in a corner of the workshop. Whilst he pretended to sleep. Walker watched all the operations of the crucible steel process. He discovered that part of the secret was in the flux. He saw the workmen break up some old green bottles which were then put in the crucibles on top of the steel.
About three months after this cold night, it is claimed that Walker's foundry in Grenoside was also making crucible steel.