AH36 | HSLA Steel | Shipbuilding Steel
AH36 | HSLA Steel | Shipbuilding Steel
AH36 is a high-strength shipbuilding steel used worldwide. It meets the ASTM A131/A131M standard. The “A” stands for the shipbuilding grade, “H” indicates high strength, and “36” represents the minimum yield strength of 36,000 psi. Equivalent grades include ABS AH36 and LR AH36. AH36 has excellent toughness, good weldability, and high strength. It is commonly used in shipbuilding, offshore structures, and marine engineering.
Description
What Is AH36?
AH36 is a type of high-strength structural steel primarily used in shipbuilding. It is composed of 98% iron and 2% carbon and manganese. AH36 is typically supplied as flat plates or sections and is solid with a standard steel color. This steel is known for its high strength, toughness, and good weldability, which makes it suitable for the harsh conditions at sea. AH36 is predominantly used in the construction of ship hulls and offshore structures. It is processed through hot rolling, ensuring its strength and durability. AH36 can be further classified under the ASTM A131/A131M standard for structural steels in marine applications.Characteristics of AH36
AH36 steel is strong, tough, and weldable. It resists harsh marine conditions well. Its high tensile strength makes it ideal for shipbuilding. This steel is also durable and reliable for offshore structures. Alternative steel grades like DH36, EH36, and FH36 can offer higher strength or toughness. AH36 is mainly used in ship hulls, offshore platforms, and marine structures.Chemical Compositions
| Element | Content (%) |
|---|---|
| Carbon, C | ≤ 0.18 |
| Manganese, Mn | 0.90-1.60 |
| Silicon, Si | ≤ 0.50 |
| Phosphorus, P | ≤ 0.035 |
| Sulfur, S | ≤ 0.035 |
| Aluminum, Al (acid-soluble) | ≥ 0.015 |
| Nitrogen, N | ≤ 0.020 |
| Copper, Cu | ≤ 0.35 |
| Nickel, Ni | ≤ 0.40 |
| Chromium, Cr | ≤ 0.25 |
| Molybdenum, Mo | ≤ 0.08 |
| Vanadium, V | ≤ 0.05 |
| Niobium, Nb | ≤ 0.02 |
| Titanium, Ti | ≤ 0.02 |
| Calcium, Ca | ≤ 0.05 |
Physical Properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1,510 °C | 2,750 °F |
| Boiling Point | – | – |
| Thermal Conductivity | 40 W/m·K | 277 BTU·in/hr·ft²·°F |
| Electrical Conductivity | – | – |
| Specific Heat Capacity | 0.49 J/g·K | 0.117 BTU/lb·°F |
| Thermal Expansion Coefficient | 12 µm/m·°C | 6.7 µin/in·°F |
| Electrical Resistivity | 0.2 µΩ·m | 7.87 µΩ·in |
Mechanical Properties
AC (Air Cooled) Sate
| Property | Metric Units | Imperial Units |
|---|---|---|
| Tensile Strength | 510-690 MPa | 74-100 ksi |
| Yield Strength | 355 MPa | 51.5 ksi |
| Brinell Hardness HB | 170-210 | 170-210 |
| Rockwell Hardness HRB | 73 – 91 | 73 – 91 |
| Vickers Hardness HV | 180 – 230 | 180 – 230 |
| Elongation | 21% | 21% |
| Elastic Modulus | 200 GPa | 29 msi |
QT (Quenched & Tempered) State
| Property | Metric Value | Imperial Value |
|---|---|---|
| Tensile Strength | 490-620 MPa | 71-90 ksi |
| Yield Strength | ≥ 355 MPa | ≥ 51 ksi |
| Elongation | ≥ 21% | ≥ 21% |
| Reduction of Area | ≥ 40% | ≥ 40% |
| Impact Absorption Energy | ≥ 27 J at -40°C | ≥ 20 ft-lbs at -40°F |
| Elastic Modulus | 200 GPa | 29 msi |
Industries & Applications
| Industry | Application |
|---|---|
| Shipbuilding | Hull structures, Deck plating, Bulkheads, Keels |
| Offshore Structures | Oil rig platforms, Subsea pipelines, Wind turbine foundations, Support frames |
| Bridge Construction | Main bridge girders, Suspension cables, Bridge deck panels, Arch ribs |
| Heavy Machinery | Excavator arms, Crane booms, Bulldozer blades, Forklift frames |
| Automotive | Chassis components, Frame rails, Suspension arms, Crossmembers |
| Construction | Structural beams, Column supports, Reinforcement bars, Steel pilings |
| Pressure Vessels | Boiler shells, Reactor vessels, Heat exchangers, Storage tanks |
| Energy | Wind turbine towers, Power plant boilers, Solar panel mounts, Turbine casings |
| Tool & Die | Dies, Punches, Molds, Forming Tools |
Machining
Heat Treatment
- Normalization: Heat the steel to 900-950°C (1652-1742°F), hold until uniformly heated, then cool in still air.
- Stress Relieving: Heat to 550-650°C (1022-1202°F), hold for 1 hour per inch of thickness, then cool in still air.
- Quenching: Heat to 890-950°C (1634-1742°F), quench in water or oil.
- Tempering: Reheat to 550-700°C (1022-1292°F) based on desired properties, hold for 1 hour per inch of thickness, then cool in still air.
Surface Finish
- As Rolled (AR): Unprocessed with scale.
- Shot Blasted and Primed: Cleaned and coated to prevent corrosion.
- Pickled and Oiled: Acid-treated and oiled for rust prevention.
- Sand Blasted: Sand-cleaned for a smooth surface.
- Painted or Coated: Additional protective layers applied.
*Customization is available upon request.
Disclaimer
The provided heat treatment and surface treatment processes are general guidelines. Actual conditions may vary depending on specific applications and requirements. It is recommended to consult with a professional metallurgist or material scientist to tailor the processes to your particular needs. The information herein is not a substitute for professional advice and should not be relied upon as such.
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