Ductile Ni-Resist Iron

By alloying SG iron with Nickel, a stable austenitic nodular iron is produced, giving excellent resistance to growth and oxidation up to 925ēC.

The main application for Ni-Resist is in Gas Turbines and Automotive Exhaust and Turbocharger Systems, where temperature fluctuates between 500 and 1050ēC.  Ni-Resist is suitable in these applications because its ductility, hot strength and low coefficient of thermal expansion provide best resistance to such severe themal shocks.

Physical properties depend on operating temperatures and the exact nickel composition of the SG iron alloy. However typical values for the austenitic Ni-Resist grade D5S are detailed below:

Castings PLC Ni-Resist Ductile Iron conforms to:

ASTM AS71:1984, grade D5S
EN-GJSA-XNiSiCr35-5-2
BS 3468:1986
DIN 1694: GGG-NiSiCr35.5.2

 
Typical Chemical Composition
C 2.0% max
Si 4.0 – 6.0%
Mn 0.5 – 1.5%
Ni 34.0 – 36.0%
Cr 1.5 – 2.5%
P 0.08% max
Cu 0.50% max
 
Mechanical Properties
Tensile Strength (Rm) 380 – 500 N/mm2
Proof Stress (Rp0.2) 210 – 270 N/mm2
Elongation (A) 10 – 20 %
Modulus of Elasticity (E) 130 to 150 kN/mm2
Brinell Hardness 130 – 170 HB

Ni Resist
Ni Resist Microstructure


Guideline figures for maximum Manifold temperatures

        Max. Manifold Temp.°C        Max. Exhaust Gas Temp.°C
                     SG400/15                         700                                       770
                     SiMo 0.5%                       750                                       820
                     SiMo 1%                          780                                       820
                     SiMo Ni                            795                                       835
                     Ni Resist D5S                   870                                       950