HAYNES® 556® alloy is readily welded by Gas Tungsten Arc (GTAW), Gas Metal Arc (GMAW), Shielded Metal Arc (SMAW), and resistance welding techniques.  Submerged Arc welding is not recommended, as this process is 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 joint surface and adjacent area should be thoroughly cleaned before welding.  All grease, oil, crayon marks, sulfur compounds, and other foreign matter should be removed.  Contact with copper or copper-bearing materials in the joint area should be avoided.  It is preferable, but not necessary, that the alloy be in the solution-annealed condition when welded.

Filler Metal Selection

Matching composition filler metal is recommended for joining 556® alloy. For shielded metal-arc welding, MULTIMET® electrodes (AMS 5795) are suggested. For dissimilar metal joining of 556® alloy to nickel- or cobalt-base materials, 556® filler metal will generally be a good selection, but HASTELLOY® S alloy (AMS 5838) or HASTELLOY® W alloy (AMS 5786, 5787) welding products may be used. For dissimilar welding to iron-base materials, 556® filler metal is recommended. Please click here or the Haynes Welding SmartGuide for more information.

Preheating, Interpass Temperatures, and Postweld Heat Treatment

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.  Postweld heat treatment is not generally required for 188 alloy.  For further information, please click here.

Typical Tensile Properties

Condition Test Temperature Ultimate Tensile Strength 0.2% Yield Strength Elongation
°F °C ksi MPa ksi MPa %
Transverse Tensile RT RT 120.6 832 63.6 439 42.8
1000 540 95.6 659 41.1 283 50.3
1200 650 84.8 585 38.3 264 47.6
1400 760 63.1 435 34.1 235 44.8
All Weld Metal RT RT 107.3 739 67.3 464 43.1
1200 650 71.4 492 44.6 308 39.4
1400 760 55.2 381 42.4 292 55.2

556 - Typical crack-free face and root bends
Typical crack-free face and root bends for welded HAYNES® 556® alloy
0.5 inch (13 mm) plate and matching filler metal.
Bend radius was 0.75 inch (19 mm).