L3, L4 cast iron

Cast iron - iron alloy with carbon (more than 2% C), separate into the undoped and alloyed, containing chrome, nickel, manganese and other doping elements.
On structure distinguish white iron (with a white fracture) in which carbon is in a type of cement carbide, and gray iron (with a gray fracture) in which carbon is in the basic in the form of graphite. Gray iron is subdivided on gray foundry, high - strength, forgeable, heat - resistant, heat resisting, corrosion - resistant and antifriction.

Designation of brands of different groups of cast iron:
• conversion pig iron - P1, P2; conversion pig iron for castings - PL1, PL2, conversion phosphorous pig iron - PF1, PF2, PF3, conversion PVK1, PVK2, PVK3 high - duty cast iron
• cast iron with the SCh lamellar graphite; the digits standing after the letters "SCh" designate size temporary to tear resistance in kgf/mm;
• the AChS antifriction cast iron - antifriction gray, AChV - antifriction high - strength, AChK - antifriction forgeable;
• cast iron with globular raphite for castings of VCh; digits after the letters "VCh" mean temporary tear resistance in kgf/mm;
• the cast iron alloyed with special properties Ch;
letters after a letter "Ch" mean doping elements: X - chrome, With - silicon, - manganese, N - nickel, D - copper, M - molybdenum, T - titanium, P - phosphorus, Yu - aluminum. Digits after letters mean the average content of the basic alloying elements as a percentage.
The letter "Sh" at the end of a pig iron grade specifies that cast iron has graphite of spherical shape.
• KCh malleable iron; the digits standing after the letters "KCh" mean temporary tear resistance in kgf/mm and percentage elongation as a percentage.