Nitrodur 8550 QT: High-Performance Nitriding Steel for Automotive and Mechanical Applications

1.8550 (34CrAlNi7-10) is a nitriding steel used in automotive and mechanical industry for heat-treated parts which the surface needs to have high wear resistance.

Properties

General

Property	Value
Density	7.6 g/cm³

Dimension

Property	Value	Comment
Diameter	250 mm	max.

Mechanical

Property	Value	Comment
Charpy impact energy, V-notch	30 - 35 J
Elastic modulus	210 GPa
Elongation	10 - 13 %	A5
Hardness, Brinell	248 [-]	annealed
Tensile strength	800 - 1100 MPa
Yield strength	600 - 680 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion	100 °C	1.11e-05 1/K	for 20°C to the mentioned temperature
	200 °C	1.21e-05 1/K	for 20°C to the mentioned temperature
	300 °C	1.29e-05 1/K	for 20°C to the mentioned temperature
	400 °C	1.35e-05 1/K	for 20°C to the mentioned temperature
Specific heat capacity		420 J/(kg·K)
Thermal conductivity		42.6 W/(m·K)

Electrical

Property	Value
Electrical resistivity	1.9e-07 Ω·m

Chemical properties

Property	Value
Aluminium	0.8 - 1.2 %
Carbon	0.3 - 0.37 %
Chromium	1.5 - 1.8 %
Iron	Balance
Manganese	0.4 - 0.7 %
Molybdenum	0.15 - 0.25 %
Nickel	0.85 - 1.15 %
Phosphorus	0.025 %
Silicon	0.4 %
Sulfur	0.035 %

Technological properties

Property
Application areas	It is used in Automotive and Mechanical engineering for heat-treated components which have been subjected to very high wear stresses, such as cam plates, eccentrics or pinion shafts.
Heat Treatment	Soft annealing: 650-700°C (Slow furnace cooling down), Quenching: 870-930°C (Oil, Water, Polymer), Tempering: 580-700°C (Air), Nitriding: 480-570°C
Hot forming	It is formable at 850-1050°C and should then cooled slowly.
Processing history	Quenched and Tempered
Welding	It is difficult to weld and should will not used be in welded constructions.

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Metal