41NiCrMo7-3-2, 1.6563, A320 L43 - structural alloy steel

41NiCrMo7-3-2, 1.6563, A320 L43 - Engineering steel for quenching and tempering according to EN 10263-4 and ASTM A320

41NiCrMo7-3-2, 1.6563, 4340 – description

The steel is used in factories and power stations. Gear, pipes and fasteners are the most common elements made of this alloy.

The steel is often used for making elements operating in high and, especially, very low temperature. The parts made from this alloy can operate in a large range of temperature, from -101°C to +343°C.

Welding is doable when the alloy is in the annealed condition, but welding in hardened or tempered state should be avoided. Pre-heating to approximately 200-300°C is needed. Cool slowly in ash or sand. Stress-relieving of welded parts is recommended.

Physical and mechanical properties

Physical properties of 41NiCrMo7-3-2, 1.6563 steel:

• Density: 7.85 g/cm³

L43 grade mechanical properties

• Rods for fasteners (bolts) for low-temperature service:
  • Quenched and tempered (+QT):
    • Yield strength Re: > 725 MPa
    • Tensile strength Rm: > 860 MPa
    • Elongation A: > 18 %
    • Percent reduction of area Z: > 50 %
    • Impact energy KV. -100°С: > 27 J
    • Hardness HRC: < 35
    • Hardness HB: < 321

41NiCrMo7-3-2, 1.6563 mechanical properties

• Rods for fasteners for low-temperature service:
  • Quenched and tempered (+QT):
    • Diameter D: < 100 mm
      • Yield strength Re: > 725 MPa
      • Tensile strength Rm: 860-1060 MPa
      • Elongation A: > 16 %
      • Percent reduction of area Z: > 50 %
      • Impact energy KV. 20°С: > 50 J
    • Diameter D: 100-160 mm
      • Yield strength Re: > 690 MPa
      • Tensile strength Rm: 790-950 MPa
      • Elongation A: > 15 %
      • Percent reduction of area Z: > 50 %
      • Impact energy KV. 20°С: > 50 J
      • Impact energy KV. -100°С: > 27 J
• Bars for cold forming:
  • Spheroized or spheroized and peeled (+AC or +AC+PE):
    • Diameter D: 5-40 mm
      • Yield strength Re: < 720 MPa
      • Percent reduction of area Z: > 58 %
  • Spheroized, cold-drawn and spheroized again (+AC+C+AC):
    • Diameter D: 2-5 mm
      • Yield strength Re: < 710 MPa
      • Percent reduction of area Z: > 60 %
    • Diameter D: 5-40 mm
      • Yield strength Re: < 700 MPa
      • Percent reduction of area Z: > 60 %
  • Spheroized, cold-drawn, spheroized again and skin passed (+AC+C+AC+LC):
    • Diameter D: 2-5 mm
      • Yield strength Re: < 750 MPa
      • Percent reduction of area Z: > 58 %
    • Diameter D: 5-40 mm
      • Yield strength Re: < 740 MPa
      • Percent reduction of area Z: > 58 %

Heat treatment and working

Recommended working and heat treatment parameters for 1.6563 alloy:

• Quenching: 840-880 °C
• Tempering: 600-700 °C
• Normalizing annealing: 840-880 °C

We deliver this steel alloy as:

• Bars
• Wires
• Forgings

Replacements, equivalents and other designations:

1.6563, 41NiCrMo7-3-2, A320 grade L43, SA320 grade L43, 4340