Perhaps better to call them cast semi steel, 'cast steel' is a material, not a process, it is a subset of crucible steel. Making a vise by 'casting' with steel is usually actully casting with a blend of cast iron and remelted steel. It is , in theory possible to cast actual steel, but it is not easy, and I suspect very few vices are truely pure steel that has been cast....
There are also different kinds of cast iron, which is mostly why sometimes a cast iron vise will be reasonably durable, and others break with the slightest tap..