Welding and Fabrication

HASTELLOY® G-35® alloy is very amenable to the Gas Metal Arc (GMA/MIG), Gas Tungsten Arc (GTA/TIG), and Shielded Metal Arc (SMA/Stick) welding processes.  For matching filler metals (i.e. solid wires and coated electrodes) that are available for these processes, and welding guidelines, please click here.

Wrought products of HASTELLOY® G-35® alloy are supplied in the Mill Annealed (MA) condition, unless otherwise specified. This solution annealing procedure has been designed to optimize the alloy’s corrosion resistance and ductility. Following all hot forming operations, the material should be re-annealed, to restore optimum properties. The alloy should also be re-annealed after any cold forming operations that result in an outer fiber elongation of 7% or more. The annealing temperature for HASTELLOY® G-35® alloy is 1121°C (2050°F), and water quenching is advised (rapid air cooling is feasible with structures thinner than 10 mm (0.375 in). A hold time at the annealing temperature of 10 to 30 minutes is recommended, depending on the thickness of the structure (thicker structures need the full 30 minutes). More details concerning the heat treatment of HASTELLOY® G-35® alloy, click here.

HASTELLOY® G-35® alloy can be hot forged, hot rolled, hot upset, hot extruded, and hot formed. However, it is more sensitive to strain and strain rates than the austenitic stainless steels, and the hot working temperature range is quite narrow. For example, the recommended start temperature for hot forging is 1204°C (2200°F) and the recommended finish temperature is 954°C (1750°F). Moderate reductions and frequent re-heating provide the best results, as described here. This reference also provides guidelines for cold forming, spinning, drop hammering, punching, and shearing of the HASTELLOY® alloys. G-35® alloy is stiffer than most austenitic stainless steels, and more energy is required during cold forming. Also, G-35® alloy work hardens more readily than most austenitic stainless steels, and may require several stages of cold work, with intermediate anneals.

While cold work does not usually affect the resistance of HASTELLOY® G-35® alloy to general corrosion, and to chloride-induced pitting and crevice attack, it can affect resistance to stress corrosion cracking. For optimum corrosion performance, therefore, the re-annealing of cold worked parts (following an outer fiber elongation of 7% or more) is important.

Tensile Data for Weldments

Welding Process   Form  Test Temperature   0.2% Offset Yield Strength Ultimate Tensile Strength  Elongation 
°F °C ksi MPa ksi MPa   %
Gas Tungsten Arc Welding (GTAW) Transverse Sample from Welded Plate of Thickness 12.7 mm/0.5 in RT RT  63.5  438  101.0  696   44.0
500 260  44.9  310  79.0  545   40.0
1000 538  36.1  249  65.0  448   37.0
Synergic Gas Metal Arc Welding (GMAW) Transverse Sample from Welded Plate of Thickness 12.7 mm/0.5 in RT  RT  66.5  459  105.0  724   31.5
500  260  48.6  335  80.5  555   43.0
1000  538  35.7  246  72.7  501   51.0
All Weld Metal Sample of Diameter 12.7 mm/0.5 in from Cruciform RT  RT  70.5  486  101.0  696   43.0
500  560  48.8  336  78.0  538   46.0
1000  238  43.8  302  64.0  441   42.0

Charpy V-Notch Impact Data for Weldments

Welding Process
Form  Notch Position  Test Temperature  Impact Strength 
°F  °C   ft.lbf 
Synergic Gas Metal Arc Welding (GMAW)
Transverse Sample from Welded Plate of Thickness 12.7 mm/0.5 in  Mid-Weld  RT  RT  201  273 
-320  -196  153  207 
Heat Affected Zone  RT  RT  >264  >358 
-320  -196  >264  >358 

Room Temperature Charpy V-Notch Data for Aged Weldments
(Synergic Gas Metal Arc Welding, Transverse Samples from Welded 12.7 mm Plate)

Notch Position Aging Time  Aging Temperature  Impact Strength 
ºF  ºC  ft.lbf 
Mid-Weld 2000  800  427  223  302 
Mid-Weld  2000  900  482  219  297 
Mid-Weld  2000  1000  538  224  304 
Mid-Weld  2000  1100  593  125  169 
Mid-Weld  2000  1200  649  79  107