Nickel and nickel alloys · Alloy G-30 / Hastelloy G-30 / UNS N06030

Hastelloy G-30 Alloy (UNS N06030): Engineering Reference Guide

Engineering Specifications and Nomenclature of Hastelloy G-30 Alloy

Product TypesMarking and Trade NamesKey Specifications
Wire, precision strip, bar stock, sheet, strips, forgings, seamless and welded fittingsAlloy G-30, Hastelloy G-30, UNS N06030ASTM / ASME
Wire, precision strip, bar stock, sheet, strips, forgings, seamless and welded fittingsAlloy G-30, Hastelloy G-30, UNS N06030ASTM / ASME
Wire, precision strip, bar stock, sheet, strips, forgings, seamless and welded fittingsAlloy G-30, Hastelloy G-30, UNS N06030ASTM B581, ASTM B582, ASTM B622, ASTM B619, ASTM B775, ASTM B626, ASTM B751, ASTM B366, ASTM B462, ASTM B472

Hastelloy G-30 (UNS N06030) is a nickel-chromium alloy, alloyed with iron and molybdenum, specifically designed for operation in highly aggressive industrial environments. Its composition provides excellent resistance in concentrated phosphoric acid (P₂O₅), used in the chemical industry. EV Group China technologists confirm its outstanding resistance to chloride stress corrosion cracking (SCC), which is a critical factor for chemical production equipment.

Standardized Chemical Composition of Hastelloy G-30 Alloy (% by mass)

NiBase
C<0.03
Cu1.0-2.4
P<0.04
S<0.02
Mn<1.5
Si<0.8
Cr28.0-31.5
Mo4.0-6.0
Co<5.0
W1.0-4.0
Nb0.3-1.5
Fe13.0-17.0

A high chromium concentration (up to 31.5%) forms a stable passive film on the alloy surface, providing exceptional resistance in oxidizing environments, particularly in nitric acid. Alloying with molybdenum and tungsten significantly increases resistance to localized corrosion and expands the application range to reducing environments, including solutions of hydrochloric and sulfuric acids.

Mechanical Properties of G-30 Alloy in Annealed Condition

Tensile strength, max.Rockwell Hardness, max.
100 ksi81 HRBW
689 MPa81 HRBW
0.2% Yield Strength, max.Elongation at break, min.
51 ksi54 %
352 MPa54 %
54 %

Thermophysical Parameters of G-30 Alloy Depending on Temperature

TemperatureElectrical ResistivityDynamic Modulus of Elasticity
RT (20°C)1.16 μohm.m-
RT (20°C)1.16 μohm.m-
100°C1.17 μohm.m202 GPa
200°C1.19 μohm.m196 GPa
300°C1.21 μohm.m195 GPa
400°C1.23 μohm.m192 GPa
500°C1.24 μohm.m187 GPa
600°C1.25 μohm.m-
Thermal Conductivity
10 W/m.°C
10 W/m.°C
12 W/m.°C
14 W/m.°C
17 W/m.°C
19 W/m.°C
20 W/m.°C
21 W/m.°C

Physical Constants and Processing Aspects

The calculated density of Hastelloy G-30 material at room temperature is 8.22 g/cm³.

G-30 alloy has excellent weldability with all standard arc welding methods (TIG, MIG). To prevent the formation of intermetallic phases, which reduce corrosion resistance and ductility, EV Group China technologists insist on minimizing heat input and strictly adhering to subsequent heat treatment regimes. All wrought semi-finished products are supplied in an austenitized (quenched) condition to ensure a homogeneous microstructure and maximum corrosion resistance.

The technological regulation for Hastelloy G-30 alloy heat treatment provides for solid solution annealing at a temperature of 1177°C (2150°F) with mandatory rapid cooling (water quenching or forced air quenching) to fix the austenitic structure. Hot plastic deformation, including forging, should be carried out in the temperature range from 1149°C (2100°F) to 927°C (1700°F).