Fine-grained high-quality hot alloy steel,4Cr5MoSiV,high hardenability, high toughness, and fine-grained. Fine-grained high-quality hot alloy steel,4Cr5MoSiV,high hardenability, high toughness, and fine ... of composition designhigh hardenability, high toughness, and fine-grained.The use of Electric arc furnace (EAF+ refiningLF+ VacuumVD + Vacuum Electro-slag (ESRmake the ...