Chemical composition 
 C Cr Mo Ni Si V Mn 
 0.56 0.25 0.1 0.7 1.1 0.5 1.7 
 Thermal effect of high toughness characteristics of steel, has excellent resistance to high temperature tempering softening; and 1.2713 in comparison, has a better hardenability. General delivery hardness HRC40 ~ 42 
 Apply all the standard forging die materials, particularly the air drop hammer die. Also used for punch die forging parts, hot shears, extrusion machine parts, mold base, forging the whole side mode. 
 Heat treatment 
 Soft annealed hardness HB cooling methods 
 650 ~ 700 ° C furnace cooling HB250max Xu 
 Hardness after quenching HRC quenching 
 Oil cooler oil cold high pressure air air 
 830 ~ 870 ° C 860 ~ 900 ° C HRC58 HRC56 
 Tempering temperature 100 200 300 400 450,500,550,600,650 
 After oil quenching HRC 55 54 52 49 47 46 43 38 34 
 Air-cooled after quenching HRC 55 52 50 47 45 43 40 36 32