HAYNES® 718 alloy is readily welded by Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW), Shielded Metal Arc Welding (SMAW), Electron Beam (EB) and resistance welding techniques. Its welding characteristics are similar to those for HASTELLOY® X alloy. Submerged Arc Welding (SAW) and oxyacetylene are not recommended as these processes are characterized by high heat input to the base metal and slow cooling of the weld. These factors can increase weld restraint and promote cracking.
Base Metal Preparation
The welding surface and adjacent regions should be thoroughly cleaned with an appropriate solvent prior to any welding operation. All greases, oils, cutting oils, crayon marks, machining solutions, corrosion products, paint, scale, dye penetrant solutions, and other foreign matter should be completely removed.
Filler Metal Selection
HAYNES® 718 alloy should be joined using matching filler metal (AWS A5.14 ERNiFeCr-2, AMS5832). For welding 718 alloy to other alloys, HASTELLOY® S (AMS 5838) or W (AWS A5.14 ERNiMo-3, AMS 5786) filler wires are suggested. Please click here or see the Haynes Welding SmartGuide for more information.
Preheating and Interpass Temperatures
Preheat is not required. Preheat is generally specified as room temperature (typical shop conditions). Interpass temperature should be maintained below 200°F (93°C). Auxiliary cooling methods may be used between weld passes, as needed, providing that such methods do not introduce contaminants. For further information, please click here.
Postweld Heat Treatment
HAYNES® 718 alloy is normally used in the fully-aged condition. Following forming and welding, a full solution anneal prior to aging is often employed in order to develop the best joint and overall fabrication properties. The best practice is dependent upon the specific condition of the fabrication prior to aging. Contact Haynes International, Inc. for further information.
Nominal Welding Parameters
Details for GTAW, GMAW and SMAW welding are given here. Nominal welding parameters are provided as a guide for performing typical operations and are based upon welding conditions used in our laboratories.