... ,EN9,EN19,EN24,EN31,51200,SUJ2,100Cr6,K310,34CrNiMo6,36CrNiMo4,42CrMo4,86CrMoV7,Cr 2%, Cr3%, Cr 5%, etc.3 Surface Hardness ... reduction ratio:≥46 Manufacturing process:steel ingot→forging→rough machining→QT→2th rough machining→induction quenching→finishing machining→packing→delivery7 Quality ...