DIN 17745 NiFe48Cr: Low-Expansion Alloy for Glass Sealing & Surge Protection

The expansion material NiFe48Cr possesses a relatively low thermal expansion at 450 °C. (Temperature interval RT to 400 °C: coefficient of thermal expansion 9.9 to 10.7 10^-6 K^-1). It is applied for sealings for soft glasses as well as as surge voltage protection. The alloy is of good durability at normal temperatures in air with normal weather conditions as well as in fresh water and sea water. NiFe48Cr is well weldable by using the tungsten inert-gas method and is also applied as welding filler material.

Properties

General

Property	Temperature	Value
Density	20.0 °C	8.3 g/cm³

Mechanical

Property	Temperature	Value	Comment
Elastic modulus	20.0 °C	157 GPa
Elongation	20.0 °C	3 - 30 %
Hardness, Brinell	20.0 °C	135 - 250 [-]
Poisson's ratio	23.0 °C	0.28 [-]	Typical for Nickel Iron Alloy
Tensile strength	20.0 °C	550 - 800 MPa
Yield strength Rp0.2	20.0 °C	250 - 790 MPa

Thermal

Property	Temperature	Value	Comment
Coefficient of thermal expansion	100.0 °C	1.03E-5 1/K
	200.0 °C	1.03E-5 1/K
	300.0 °C	1.02E-5 1/K
	400.0 °C	1.02E-5 1/K
	500.0 °C	1.03E-5 1/K
	600.0 °C	1.1E-5 1/K

Melting point		1450 °C	Typical for Nickel Iron Alloy
Specific heat capacity	20.0 °C	500 J/(kg·K)
Thermal conductivity	20.0 °C	17 W/(m·K)

Electrical

Property	Temperature	Value
Electrical resistivity	20.0 °C	4.3E-7 Ω·m

Chemical properties

Property	Value
Carbon	0.02 %
Chromium	0.7 - 1.5 %
Iron	45 - 48 %
Manganese	1 %
Nickel	49.18 %
Silicon	0.3 %

SEW 087 Grade WTSt 37-3: Normalized and Normalized Formed Steel for Structural Applications DIN 17480 Grade X45 CrNiW 18-9: Heat‑Treated & Precipitation Hardened Valve Steel for High‑Temperature Applications

Metal