To cast high carbon steels you would probably want to go with a vacuum melt system to prevent contamination of the metal as various gasses tend to be absorbed by the molten steel and various alloying components can be "burnt off".
You also need to be carefull of alloy element segregation when the melt is cooling; (take a look at zone refining for an extreme case).
Cooling from a melt is generally done slowly and slow cooling makes for a larger grain size that is weaker. There are methods to get around all of this but they tend to be high tech and expensive.
Probably a lot more efficient to find a place that does such castings and work with them to create the molds and cast the pieces.
Remember that to do a one-off you should expect it to cost several times what even a low number production casting piece costs. So *MUCH* *MUCH* *MUCH* chaper to buy one of his than to try to replicate one by casting. Me I'd forge my own.
If you look at historical methods of casting steel, they would cast an in got and then refine the grain by substantial forging---think steam hammers---and then use the hammered out stock to make things from. They did not cast to shape.
__________________
Thomas
|