Introduction
5454 aluminum is the 5xxx alloy specifically rated for elevated-temperature marine and chemical service — its magnesium content (2.4–3.0%) stays deliberately below the 3% stress-corrosion-cracking threshold, so it resists intergranular attack at temperatures up to about 150°C, where 5083 and 5456 become susceptible. This guide covers where 5454 fits against 5052, 5083, and 6061, what the temper options mean for pressure vessels, and how to decide whether it is the right grade for hot-chemical or warm-marine applications.
Chemical Composition
- Magnesium: 2.4–3.0%
- Manganese: 0.5–1.0%
- Iron: ≤0.4%
- Silicon: ≤0.25%
- Copper: ≤0.1%
- Chromium: 0.05–0.2%
- Zinc: ≤0.25%
- Titanium: ≤0.2%
- Balance: Aluminum
Key Properties
Strength and Thermal Stability
5454 is non-heat-treatable. In H32 temper, tensile strength is approximately 250–305 MPa with yield in the 180–230 MPa range. In H34, tensile reaches ~270–330 MPa. The defining advantage of 5454 over 5083 is NOT higher room-temperature strength — it is the ability to hold that strength without stress-corrosion-cracking at temperatures above 65°C, where high-Mg 5xxx alloys (5083 at 4.5% Mg, 5456 at 5% Mg) become susceptible to intergranular attack. For chemical-process and hot-marine applications, this thermal window makes 5454 the standard pressure-vessel grade in the 5xxx family.
Corrosion Resistance
5454 resists saltwater, marine atmosphere, mild chemical exposure, and industrial waste. The moderate Mg level keeps the corrosion resistance strong while staying below the SCC-susceptibility threshold. It is one of the few aluminum alloys rated for ammonium nitrate and certain petrochemical storage at moderate temperatures.
Weldability
5454 welds with GTAW (TIG) and GMAW (MIG) using 5356 or 5554 filler. 5356 provides higher weld strength but slightly reduces SCC resistance in the weld zone at elevated temperatures; 5554 matches the base Mg level and preserves the full thermal rating. For pressure-vessel code work, the filler choice should be confirmed against the design temperature and code requirements.
Formability
In O (annealed) and H32 tempers, 5454 bends, roll-forms, and stamps well. The work-hardening rate is moderate — higher than 5052 but lower than 5083, making it practical for pressure-vessel forming and tank fabrication without intermediate annealing steps.
5454 vs. Other Alloys
5454 vs. 5052
5052 is the baseline low-cost Al-Mg sheet alloy (2.2–2.8% Mg) — general-purpose marine and sheet-metal work. 5454 adds manganese (0.5–1.0%) for higher strength at comparable Mg levels and is specifically rated for elevated-temperature service. The choice: 5052 for standard sheet-metal and general enclosure work; 5454 when the part will see heat or aggressive chemical exposure and a pressure-vessel or tank-code rating is required.
5454 vs. 5083
5083 has higher Mg (4.0–4.9%) and delivers stronger room-temperature tensile performance (~305 MPa UTS in H116 vs. 5454-H32’s ~275 MPa). But 5083 is NOT recommended above 65°C due to SCC risk. 5454 is the standard alternative when the service temperature exceeds that threshold — chemical transport tanks, warm-process vessels, and marine exhaust components are classic 5454 applications.
5454 vs. 6061
6061-T6 is heat-treatable, machinable, and stronger at room temperature — but it is not the default pressure-vessel or chemical-service grade. Bare 6061 corrodes in saltwater and many chemicals. 5454 is the code-qualified 5xxx choice for welded pressure vessels, chemical storage, and elevated-temperature marine service where corrosion integrity matters more than peak tensile strength.
Common Tempers
- O: Annealed — maximum formability. Used when the part will be formed and then welded without needing high as-delivered strength.
- H32: Strain-hardened and stabilized to quarter-hard. The most commonly specified temper for pressure vessels and chemical tanks — balances strength and formability.
- H34: Half-hard stabilized. Higher strength where forming requirements are less demanding. Typical for flat and lightly formed pressure-vessel components.
Go/No-Go Limits
Use this quick reference to decide whether 5454 fits your application.
Go — use 5454 when:
- Service temperature is between 65°C and 150°C and the environment involves saltwater, chemicals, or industrial waste — 5454 is the 5xxx alloy specifically engineered NOT to stress-corrosion-crack in this thermal window. Typical applications: chemical transport tanks, warm-process pressure vessels, marine exhaust and cooling-system components.
- The application is a welded pressure vessel or storage tank requiring code qualification — 5454 is recognized in ASME pressure-vessel code for moderate-temperature aluminum construction. Typical applications: ammonium nitrate storage, petrochemical process vessels, road tanker bodies.
- Corrosion resistance plus weldability plus thermal stability are all required in one alloy — 5454 covers the intersection that 5083 (SCC risk above 65°C), 6061 (corrosion in chemicals), and 304 stainless (weight penalty) each fail individually.
No-Go — do not use 5454 when:
- Room-temperature tensile strength above 330 MPa is the primary requirement — 5083-H116 delivers higher strength at room temperature; 6061-T6 or 7075-T6 are stronger still if heat-treatable alloys are acceptable.
- Service temperature exceeds 150°C continuously — aluminum loses strength rapidly above ~200°C regardless of alloy; stainless steel or nickel alloys become the standard material choice.
- Anodizing quality is a cosmetic or specification requirement — like all 5xxx alloys, 5454 produces a less uniform anodized finish than 6xxx grades.
- High-volume CNC machining is the primary production method — 5xxx alloys are gummier than 6xxx; 6061-T6 or 7075-T6 are standard machining-grade aluminum.
Applications
The Go/No-Go criteria above cover selection logic. The list below maps specific systems where 5454 is standard practice:
- Chemical processing — storage tanks, transport vessels, piping for ammonium nitrate and petrochemical service
- Marine — exhaust system components, cooling-water piping, warm-process tanks
- Pressure vessels — ASME-code welded aluminum vessels for moderate-temperature service
- Transportation — road tanker bodies, rail tank cars for chemical and fuel transport
- Industrial — heat-exchanger shells, process piping, scrubber components
Conclusion
5454 is not the strongest 5xxx alloy — 5083 and 5456 both deliver higher room-temperature tensile strength. What 5454 gives you instead is a working temperature window between 65°C and 150°C where high-Mg 5xxx alloys become unreliable. For chemical transport, warm-process vessels, and hot-marine service, this thermal stability is the reason 5454 appears in pressure-vessel codes where 5083 does not. The trade-off is moderate strength and a cost premium for the narrower availability of a specialty temper-controlled grade.
Linsy Aluminum stocks 5454 in plate, sheet, and custom-cut dimensions, with low-MOQ production available for non-stock specifications. Full MTC documentation, composition certification, and SGS mechanical testing reports are available for every order. If the project involves a specific temper, code qualification, or chemical-service requirement, send the specification for a technical review.
Frequently Asked Questions
What makes 5454 suitable for elevated-temperature service?
The magnesium content is deliberately kept below 3% (range: 2.4–3.0%). Above ~3% Mg, 5xxx alloys become susceptible to stress-corrosion cracking at temperatures above 65°C as Mg-rich beta-phase precipitates along grain boundaries. By capping the Mg at 3%, 5454 minimizes this precipitation — making it usable up to approximately 150°C while retaining corrosion resistance.
Can 5454 be welded?
Yes — GTAW (TIG) and GMAW (MIG) with 5356 or 5554 filler are standard. 5356 gives higher as-welded strength but slightly reduces the elevated-temperature SCC resistance in the weld zone. 5554 matches the lower Mg content and preserves the full thermal rating. For code-qualified pressure-vessel work, confirm the filler specification against the design temperature.
How does 5454 compare to 5083 in pressure-vessel applications?
5083 is stronger at room temperature (~305 MPa UTS vs. 5454’s ~275 MPa) and is the standard shipbuilding grade. But 5083 is not recommended above 65°C due to SCC risk, while 5454 maintains its pressure-vessel code rating up to ~150°C. The choice depends on whether the design temperature crosses the 65°C line — if it does, 5454 is the specified 5xxx alloy.
What is the main difference between 5454-H32 and H34?
H32 is quarter-hard and stabilized — slightly softer and more formable, the standard choice for welded pressure vessels where forming is part of the fabrication. H34 is half-hard — higher strength with somewhat lower formability, used for flatter components with less demanding forming requirements. Both are stabilized to lock in the cold-worked properties.
What filler metal should be used for welding 5454?
5356 (Al-5%Mg) is the most common choice and gives higher as-welded strength. 5554 (Al-2.7%Mg) matches the base Mg level more closely and preserves the full elevated-temperature corrosion resistance. The choice depends on whether strength or thermal SCC resistance ranks higher in the service conditions. For code work, confirm the filler with the welding procedure specification.
