5083 forged aluminum round bar is a high-strength, non-heat-treatable aluminum-magnesium alloy specifically engineered to deliver exceptional performance in extremely harsh environments, particularly marine and cryogenic applications. Its precisely controlled forging process optimizes its internal microstructure, providing superior toughness, corrosion resistance, weldability, and fatigue strength, making it an ideal choice for shipbuilding, oil & gas, cryogenic engineering, and military applications:

Primary Alloying Elements:

Magnesium (Mg): 4.0-4.9% (primary strengthening element, provides high strength and good weldability)

Manganese (Mn): 0.4-1.0% (further enhances strength and refines grain)

Chromium (Cr): 0.05-0.25% (inhibits recrystallization, improves stress corrosion resistance)

Base Material:

Aluminum (Al): ≥93.2% (balance)

Controlled Impurities:

Iron (Fe): ≤0.40% max

Silicon (Si): ≤0.40% max

Copper (Cu): ≤0.10% max

Zinc (Zn): ≤0.25% max

Titanium (Ti): ≤0.15% max

Other elements: ≤0.05% each, ≤0.15% total

Premium Forging Process:

Melt Preparation:

High-purity primary aluminum (99.7% minimum)

Precise alloying element additions with ±0.05% tolerance

Advanced filtration through ceramic foam filters (30-40 ppi)

Advanced degassing treatment (hydrogen < 0.10 ml/100g)

Grain refinement with Al-Ti-B master alloy

Direct-chill (DC) semi-continuous casting to produce large-sized ingots

Homogenization:

420-450°C for 10-24 hours

Uniform temperature control: ±5°C

Controlled cooling rate: 15-25°C/hour

Eliminates microsegregation and homogenizes alloy composition

Billet Preparation:

Surface conditioning (scalping)

Ultrasonic inspection (100% volumetric)

Preheating: 380-420°C for uniform temperature

Forging Sequence:

Open-die preforming: 380-420°C

Closed-die or radial forging for finishing: 350-400°C

Hydraulic press capacity: 2,000-10,000 tons (depending on bar size)

Computer-controlled ram speed and pressure

Multi-stage forging to optimize grain flow and refine grains

Minimum reduction ratio: 3:1 to 5:1, ensuring dense and uniform internal structure

Annealing (O Temper) / Strain Hardening (H Tempers):

O Temper: 340-360°C for 1-3 hours, ensuring maximum ductility

H Tempers: Achieved through cold working (e.g., stretching, straightening), such as H111, H112

Final Processing:

Surface conditioning (e.g., peeled, ground, or precision turned)

Precision straightening

Dimensional verification

Surface quality inspection

All production stages are subject to stringent quality control and traceability management.

 

Property	O (Annealed)	H111	H112	Test Method
Ultimate Tensile Strength	270-305 MPa	290-330 MPa	280-320 MPa	ASTM E8
Yield Strength (0.2%)	110-135 MPa	130-160 MPa	115-145 MPa	ASTM E8
Elongation (2 inch)	16-22%	14-20%	16-22%	ASTM E8
Hardness (Brinell)	65-75 HB	75-85 HB	70-80 HB	ASTM E10
Fatigue Strength (5×10⁸ Cycles)	120-140 MPa	130-150 MPa	125-145 MPa	ASTM E466
Shear Strength	160-180 MPa	175-195 MPa	170-190 MPa	ASTM B769
Modulus of Elasticity	70.3 GPa	70.3 GPa	70.3 GPa	ASTM E111
Fracture Toughness (K1C, typical)	26-30 MPa√m	28-32 MPa√m	27-31 MPa√m	ASTM E399

 

Property Distribution:

Axial vs. Radial properties: <3% variation in strength properties (due to forged isotropy)

Internal property variation across large diameter bars: typically less than 5%

Core to surface hardness variation: <3 HB

Property retention after welding: Welded zones can retain over 90% of parent material strength with good ductility

Cryogenic performance: Strength and toughness even improve at -196°C (liquid nitrogen temperature), with no brittle transition

Key Microstructural Features:

Grain Structure:

Fine, uniform equiaxed grains

ASTM grain size 6-8 (45-22μm)

Forging process ensures grain flow follows the bar’s contour, enhancing mechanical properties and fatigue resistance

Uniform grain distribution across the entire cross-section, free from coarse grain segregation

Precipitate Distribution:

β-Mg₅Al₈ phase: Fine and uniformly dispersed, acting as the primary strengthening phase

AlMn or AlFeMn dispersoids: Further refines grains and inhibits recrystallization

AlCr phase: Improves stress corrosion resistance

Texture Development:

Mild texture induced by forging, designed to optimize multi-directional properties

Forged bars exhibit superior isotropy compared to rolled products

Special Features:

Continuous precipitation of β-phase at grain boundaries effectively controlled to avoid stress corrosion sensitivity

Moderate dislocation density, beneficial for work hardening

Absence of coarse primary intermetallic compounds

Parameter	Standard Range	Precision Tolerance	Commercial Tolerance	Test Method
Diameter	100-800 mm	±0.5mm up to 300mm	±1.0mm up to 300mm	Micrometer/Caliper
		±0.2% above 300mm	±0.5% above 300mm
Ovality	N/A	50% of diameter tolerance	75% of diameter tolerance	Micrometer/Caliper
Length	1000-6000 mm	±5mm	±10mm	Tape measure
Straightness	N/A	0.5mm/m	1.0mm/m	Straightedge/Laser
Surface Roughness	N/A	3.2 μm Ra max	6.3 μm Ra max	Profilometer
Cut End Squareness	N/A	0.5° max	1.0° max	Protractor

 

Standard Available Forms:

Forged Round Bar: Diameters 100mm to 800mm

Custom cut-to-length service available

Special tolerances and surface finishes (e.g., peeled, ground, precision turned) available upon request

Available in various forged tempers, such as O, H111, H112

 

Temper Code	Process Description	Optimal Applications	Key Characteristics
O	Fully annealed, softened	Applications requiring maximum formability	Maximum ductility, lowest strength
H111	Moderately strain hardened after full annealing	General structures, excellent post-weld properties	Good balance of strength and ductility
H112	Flattened only after forging	Retains residual stresses from forging	Suitable for further processing before machining
H321	Stabilized H32 temper	High strength, strict corrosion resistance requirements	Excellent SCC resistance, higher strength

 

Temper Selection Guidance:

O: For complex cold forming operations or where further deep processing is needed

H111: For structural components requiring high strength, weldability, and good corrosion resistance

H112: Used directly after forging, suitable for parts with significant machining

H321: For marine and cryogenic applications with extremely high stress corrosion cracking resistance requirements

Operation	Tool Material	Recommended Parameters	Comments
Turning	Carbide, PCD	Vc=150-400 m/min, f=0.1-0.4 mm/rev	Easy to achieve good surface finish, moderate tool wear
Drilling	Carbide, TiN coated	Vc=60-150 m/min, f=0.15-0.35 mm/rev	Through-coolant drills recommended, good for deep holes
Milling	Carbide, HSS	Vc=200-600 m/min, fz=0.1-0.25 mm	High-positive rake angle tools, large depth of cut, high feed
Tapping	HSS-E-PM, TiCN coated	Vc=15-30 m/min	Proper lubrication for good thread quality
Reaming	Carbide, HSS	Vc=50-100 m/min, f=0.2-0.5 mm/rev	H7/H8 tolerance achievable
Sawing	Carbide-tipped blade	Vc=800-2000 m/min	Efficient cutting for large diameter bars

 

Fabrication Guidance:

Machinability Rating: 70% (1100 aluminum = 100%), slightly lower machinability in strain-hardened tempers

Chip Formation: Gummy chips, tend to wrap around tools, requires good chip breakers

Coolant: Water-soluble cutting fluid (8-12% concentration), high flow rate cooling

Tool Wear: Moderate, regular tool inspection needed

Weldability: Excellent with TIG and MIG welding, one of the best weldable aluminum alloys

Cold Working: Good formability in O temper, moderate in H111 temper

Hot Working: Recommended temperature range 300-400°C

Stress Corrosion Cracking: O, H111, H112 tempers have excellent resistance to stress corrosion cracking

Cryogenic Properties: Retains or improves strength and toughness at extremely low temperatures

 

Environment Type	Resistance Rating	Protection Method	Expected Performance
Industrial Atmosphere	Excellent	Clean surface	20+ years
Marine Atmosphere	Excellent	Clean surface	15-20+ years
Seawater Immersion	Very Good	Cathodic protection or painting	10-15+ years with maintenance
High Humidity	Excellent	Clean surface	20+ years
Stress Corrosion	Excellent	Appropriate temper selection (H111/H112/H321)	Extremely low susceptibility
Exfoliation	Excellent	Standard protection	Extremely low susceptibility
Galvanic Corrosion	Good	Proper isolation	Careful design with dissimilar metals

 

Surface Protection Options:

Anodizing:

Type II (Sulfuric): 10-25μm thickness, provides additional protection and aesthetics

Type III (Hard): 25-75μm thickness, increases wear resistance and hardness

Dyeing and sealing: Enhances aesthetics and corrosion resistance

Conversion Coatings:

Chromate conversion coatings (MIL-DTL-5541): Excellent base for paints or adhesives

Chromium-free alternatives: Environmentally compliant

Painting Systems:

Epoxy primer + polyurethane topcoat: Provides excellent long-term protection, especially for marine applications

Antifouling paint: For submerged parts of ships

 

Property	Value	Design Consideration
Density	2.66 g/cm³	Lightweight design, center of gravity control
Melting Range	575-635°C	Welding and casting parameters
Thermal Conductivity	121 W/m·K	Thermal management, heat transfer design
Electrical Conductivity	34% IACS	Electrical conductivity in electrical applications
Specific Heat	897 J/kg·K	Thermal mass and heat capacity calculations
Thermal Expansion (CTE)	24.0 ×10⁻⁶/K	Dimensional changes due to temperature variations
Young’s Modulus	70.0 GPa	Deflection and stiffness calculations
Poisson’s Ratio	0.33	Structural analysis parameter
Damping Capacity	Moderate	Vibration and noise control

 

Design Considerations:

Operating Temperature Range: -200°C to +80°C (performance degrades above this)

Cryogenic Performance: Maintains or improves strength and toughness at extremely low temperatures, ideal for cryogenic structural materials

Magnetic Properties: Non-magnetic

Recyclability: 100% recyclable with high scrap value

Formability: Good in O temper, moderate in H111 temper

Dimensional Stability: Good dimensional stability after forging and stress relief

Strength-to-Weight Ratio: Advantageous in applications requiring high strength and corrosion resistance

 

Standard Testing Procedures:

Chemical Composition:

Optical emission spectroscopy

X-ray fluorescence analysis

Verification of all major elements and impurity content

Mechanical Testing:

Tensile testing (longitudinal, transverse, and radial)

Hardness testing (Brinell, multiple locations)

Impact testing (Charpy V-notch, especially for cryogenic applications)

Fatigue testing (as required)

Nondestructive Testing:

Ultrasonic inspection (100% volumetric, per ASTM B594/E2375, or AMS 2630)

Eddy current testing (surface and near-surface defects)

Penetrant inspection (surface defects)

Radiographic testing (internal macroscopic defects)

Microstructural Analysis:

Grain size determination

Precipitate and intermetallic evaluation

Grain flow pattern verification

Stress corrosion sensitivity testing

Dimensional Inspection:

CMM (Coordinate Measuring Machine) verification

Diameter, length, straightness, ovality, etc.

Standard Certifications:

Material Test Report (EN 10204 3.1 or 3.2)

Chemical analysis certification

Mechanical properties certification

Heat treatment/forging certification

Nondestructive testing certification

Conformance to ASTM B247 (forged bar), AMS 4114, EN AW-5083, etc.

 

Primary Applications:

Marine Industry:

Shipbuilding and yacht construction (hull structures, masts, deck equipment)

Offshore drilling platform structures

Desalination equipment

Submarine components

Cryogenic Engineering:

Liquefied Natural Gas (LNG) storage tanks and transfer pipelines

Aerospace cryogenic fuel tanks

Ultra-low temperature equipment components

Transportation Industry:

Railway vehicles (high-speed train bodies, freight cars)

Automotive fuel tanks and structural components

Tankers, bulk material carriers

Military and Defense:

Armored vehicle structures

Naval ship and submarine components

Military bridges

Pressure Vessels:

Medium to high-pressure vessels

Aerospace pressure vessels

Design Advantages:

Excellent corrosion resistance, especially in marine and industrial environments

Superior weldability, high weld strength with no need for post-weld heat treatment

Exceptional cryogenic toughness, with improved properties at extremely low temperatures

High strength and good ductility, suitable for structural components

Forging process optimizes grain flow and internal quality

Excellent resistance to stress corrosion cracking and exfoliation corrosion

Lightweight, contributing to energy savings and emission reduction

Non-magnetic, suitable for specific applications

Design Limitations:

Not strengthened by heat treatment

Lower strength compared to 2xxx and 7xxx series high-strength alloys

Long-term use above 65°C may lead to sensitization (Mg₂Al₃ precipitation), increasing susceptibility to stress corrosion; H111 or H321 tempers should be selected

Machinability is not as good as alloys like 6061

Relatively higher cost

Economic Considerations:

High-performance material, higher initial cost but long lifespan and low maintenance costs

Excellent corrosion resistance reduces long-term protection needs

Good weldability lowers the cost of fabricating complex structures

Lightweight properties help reduce transportation fuel costs

Sustainability Aspects:

100% recyclable, high resource utilization efficiency

Aluminum production processes are becoming increasingly environmentally friendly, with reduced energy consumption

Long service life reduces waste generation

Material Selection Guidance:

Choose 5083 when the highest levels of corrosion resistance, weldability, and cryogenic performance are required

5083 is ideal when high strength is needed for service in marine environments

For structures serving long-term at temperatures above 65°C, H111 or H321 tempers should be selected

Consider 7xxx series alloys when higher strength is paramount and corrosion resistance or cryogenic performance are not primary concerns