Úvod
5356 is the standard 5%-magnesium hliník filler alloy for welding 5xxx-series base metals — it is not a structural wrought grade but a filler wire, rod, and electrode alloy. Its high Mg content (4.5–5.5%) matches the chemistry of 5083, 5086, 5056, and 5456, keeping weld-zone corrosion compatibility and mechanical performance consistent with the parent metal. This guide covers the specification, temper variants, and how to choose between 5356 and 4043 for different base-metal and service conditions.
Chemické složení
- Magnesium: 4.5–5.5%
- Manganese: 0.05–0.2%
- Iron: ≤0.4%
- Silicon: ≤0.25%
- Copper: ≤0.1%
- Chromium: 0.05–0.2%
- Zinc: ≤0.1%
- Titanium: 0.06–0.2%
- Balance: Aluminum
Klíčové vlastnosti
Filler Performance
5356 is designed to melt, flow, and solidify into a weld bead that matches the chemistry and corrosion potential of the 5xxx base metal. The ~5% Mg level provides as-deposited tensile strength consistent with 5083 and 5086 in the as-welded condition — typically 240–290 MPa UTS depending on dilution and welding parameters. The low silicon content avoids the brittle intermetallic phases that can form in Mg-Si systems.
Corrosion Compatibility
The primary reason to choose 5356 over general-purpose fillers like 4043 is electrochemical compatibility: 5356-welded 5xxx joints resist galvanic corrosion in saltwater because the filler and base metal share a similar corrosion potential. Using 4043 to weld 5083 in marine service, for example, creates a more anodic weld bead that corrodes preferentially — this is a real failure risk in ship and boat construction.
Smyková pevnost
Typical transverse shear strength is approximately 180–190 MPa (26 ksi) — above the 4043 filler (typically ~140 MPa) and sufficient for most structural weldments in marine and automotive applications where the design load passes through the weld throat.
Anodizing Response
5356-welded joints produce a more uniform anodized appearance than 4043-welded joints, because the Mg-rich weld bead responds to anodizing similarly to the Mg-rich base metal. For architectural and decorative aluminum welding where appearance matters, color-match consistency is better with 5356.
5356 vs. 4043 Filler
This is the most common filler-selection decision in aluminum welding:
- 5356: For 5xxx base metals (5083, 5086, 5052, 5454, 5456) where corrosion compatibility, weld strength, and anodizing match matter. The standard marine and structural filler.
- 4043: For 6xxx base metals (6061, 6063) and general-purpose aluminum fabrication. Lower melting point, better fluidity, and less hot-cracking risk — but weaker and less corrosion-compatible with 5xxx base metals.
The rule: match the filler Mg level to the base metal. 5xxx base → 5356 filler. 6xxx base → 4043 or 5356 depending on anodizing and service conditions. Never use 4043 to weld 5xxx marine structures — the galvanic corrosion mismatch is a known failure mode.
Běžné stavy zpracování
- O: Annealed — maximum formability for wire feeding and spooling. Softest condition.
- H18: Full-hard — highest strength condition, commonly used for wire that will be drawn through a welding gun without excessive deformation before the arc.
- H32: Quarter-hard and stabilized — balances feedability with a moderate strength level, preferred for manual TIG rod where the welder feeds by hand.
Go/No-Go Limits
Use this quick reference to decide whether 5356 is the right filler for the job.
Go — use 5356 when:
- The base metal is a 5xxx alloy (5083, 5086, 5052, 5454, 5056, 5456) — 5356 matches the Mg content and preserves corrosion compatibility in the weld zone. Typical applications: ship panels, marine fuel tanks, structural boat and yacht construction.
- Saltwater exposure or marine atmosphere is the service condition — the electrochemical match between 5356 filler and 5xxx base metal prevents preferential weld-zone corrosion.
- Post-weld anodizing is planned and color uniformity across the weld matters — 5356 produces a better anodizing match than 4043 on 5xxx and many 6xxx base metals.
- Higher as-welded shear strength (~190 MPa) is required than 4043 can deliver (~140 MPa) — structural weldments where the load path crosses the weld throat benefit from the higher filler strength.
No-Go — do not use 5356 when:
- The base metal is a 6xxx casting alloy (e.g., 356, 319) with high silicon content — 4043 is the standard casting-repair filler and the Si-rich composition prevents hot cracking in castings.
- High-volume automated welding of 6061 extrusions where fluidity and crack resistance matter more than corrosion compatibility — 4043’s silicon content gives it better puddle fluidity and lower hot-cracking susceptibility for 6xxx production welding.
- The filler will be the primary structural load-bearing material outside a weld joint — 5356 is not a wrought structural alloy and should not be specified as base plate, sheet, or bar.
Aplikace
- Marine — ship and boat structural welding, hull plating, fuel and water tank fabrication
- Automotive — truck trailers, tanker bodies, aluminum frame welds
- Pressure vessels — 5083 and 5454 vessel weldments requiring corrosion compatibility
- Architectural — welded aluminum structures where anodizing color match is a specification requirement
Závěr
5356 hliník is not a structural alloy — it is the standard welding filler for 5xxx base metals, selected because its ~5% Mg chemistry gives it the same corrosion potential, similar as-welded strength, and better anodizing match compared to general-purpose fillers like 4043. The trade-off is that it is only a filler — the base metal selection drives the engineering decision, and 5356 follows to keep the weld zone performing like the rest of the part.
Linsy Aluminum supplies 5356 in wire (spooled for MIG and cut lengths for TIG), rod, and electrode forms, with custom diameter and packaging specifications available at low minimum order quantities. MTC and composition certification are standard for every order. If the project involves a specific filler diameter or spool weight, send the welding specification for a technical review.
Často kladené otázky
What is the difference between 5356 and 4043 filler?
5356 is an Al-5%Mg filler for welding 5xxx base metals — it matches the chemistry and corrosion potential of 5083, 5052, 5454, and similar alloys. 4043 is an Al-5%Si filler for welding 6xxx base metals — better fluidity but weaker and not corrosion-compatible with 5xxx marine alloys. The rule: 5xxx base → 5356; 6xxx base → 4043 (or 5356 if anodizing match matters).
Can 5356 be used to weld 6061 aluminum?
Yes — 5356 can be used on 6061 and typically gives a better anodizing color match than 4043. However, 4043 is often preferred for high-volume 6061 production welding because its silicon content reduces hot-cracking risk and improves puddle fluidity. For structural 6061 weldments, the choice depends on whether anodizing appearance or crack resistance matters more.
Is 5356 heat-treatable?
No — 5356, like all common aluminum filler alloys, is non-heat-treatable. Weld strength comes from the Mg content in solid solution. Post-weld heat treatment of the assembly will affect the base metal but will not precipitation-harden the 5356 filler itself.
What welding processes work with 5356 filler?
5356 is compatible with GTAW (TIG), GMAW (MIG), and plasma arc welding. It is available as spooled wire for MIG and cut-length rod for TIG. Argon or argon-helium shielding gas is standard. Confirm the wire diameter and temper (O, H18, or H32) match the welding gun and feed system.
Is 5356 suitable for marine welding?
Yes — for welding 5xxx alloys in marine service (5083, 5086, 5052 hulls and tanks), 5356 is the standard filler. Its Mg content creates an electrochemical match with the base metal, so the weld zone does not become a preferential corrosion site in saltwater. Using 4043 for marine 5xxx welds risks galvanic corrosion of the filler zone — a known failure mode in boat construction.
