AISI A514 Grade H Alloy Steel, also known as UNS K11576, is a high-strength, low-alloy steel with superior toughness, weldability, and corrosion resistance. This steel is popular among industrial manufacturers and fabricators for its unique and exceptional properties. This blog will dive into the composition, mechanical and physical properties, various uses, corrosion resistance, heat treatment, machining, and AISI A514 Grade H Alloy Steel welding.
AISI A514 Steel Composition
AISI A514 Grade H Alloy Steel comprises high carbon, chromium, and molybdenum. The carbon content of this steel ranges from 0.12% to 0.21%. This alloy steel’s maximum percentage of elements includes 0.95% manganese, 0.035% phosphorus, 0.04% sulfur, and 0.15-0.20% silicon. Molybdenum (typically between 0.50-0.67%) enhances the steel’s strength, toughness, and wear resistance. Additionally, chromium (0.80-1.10%) adds to the corrosion resistance of the steel.
| Element | Content (%) |
|---|---|
| Iron, Fe | 97 |
| Nickel, Ni | 0.85 |
| Manganese, Mn | 0.8 |
| Molybdenum, Mo | 0.5 |
| Chromium, Cr | 0.48 |
| Copper, Cu | 0.33 |
| Silicon, Si | 0.25 |
| Carbon, C | 0.10 – 0.20 |
| Vanadium, V | 0.06 |
| Boron, B | 0.003 |
AISI A514 Steel Mechanical Properties
AISI A514 Grade H Alloy Steel has excellent mechanical properties such as high strength, toughness, and superior fatigue strength. The yield strength of this alloy is 690 MPa (100 ksi), and it has a tensile strength of 760-895 MPa (110-130 ksi). The elongation at break for this alloy is approximately 18%. This steel has good thermal conductivity and can function even at low temperatures.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength, ultimate | 760 – 895 MPa | 110000 – 130000 psi |
| Tensile strength, yield (@0.200%) | 690 MPa | 100000 psi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear modulus (typical for steel) | 80.0 GPa | 11600 ksi |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Poisson’s ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break (in 50 mm) | 18% | 18% |
| Hardness, Brinell (@9.50 mm/0.374 in, for plates) | 235 – 293 | 235 – 293 |
| Hardness, Knoop (converted from Brinell hardness) | 289 | 289 |
| Hardness, Rockwell B (converted from Brinell hardness) | 98 | 98 |
| Hardness, Rockwell C (converted from Brinell hardness) | 26 | 26 |
| Hardness, Vickers (converted from Brinell hardness) | 278 | 278 |
AISI A514 Steel Physical Properties
AISI A514 Grade H Alloy Steel (UNS K11576) is a high-strength, quenched and tempered alloy steel featuring a yield strength of 100 ksi min. Its physical properties include a Brinell hardness of 217-235 HBW with an elongation at the maximum hardness of 13-15%.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.7 – 8.03 g/cm3 | 0.278 – 0.290 lb/in³ |
AISI A514 Steel Equivalents
- ASTM A514 (F)
- ASTM A517 (F)
- ASTM A592 (F)
AISI A514 Steel Uses
AISI A514 Grade H Alloy Steel is used in construction, mining, shipbuilding, and energy industries. It is commonly used in manufacturing heavy-load parts and equipment that require high strength and toughness, like bulldozer blades and excavator buckets. This alloy steel is also used for manufacturing oil rigs, platforms, and pipelines.
AISI A514 Steel Corrosion Resistance
The addition of chromium enhances the corrosion resistance of AISI A514 Grade H Alloy Steel. This steel is immune to atmospheric corrosion, making it an ideal choice for applications in harsh environments. It can be exposed to rain, snow, saltwater, and other corrosive substances without damage. However, it is prone to localized corrosion, such as pitting and crevice corrosion, when exposed to stagnant seawater, acidic solutions, and chloride ions.
AISI A514 Steel Heat Treatment
AISI A514 Grade H Alloy Steel can be heat treated using the quench and temper method, which involves heating the steel at high temperatures and then cooling it rapidly in a water or oil bath. The heat treatment process enhances the mechanical properties of the steel and improves its toughness and strength. Additionally, it can be strengthened by cold-working or strain-hardening.
AISI A514 Steel Machining
This alloy steel is rugged and robust, making it difficult to machine. It can be machined using conventional techniques, provided they are correctly applied. The use of water-soluble coolants and low speeds are recommended. Carbide tooling, rather than high-speed steel, should be used whenever possible.
AISI A514 Steel Welding
AISI A514 Grade H Alloy Steel can be welded using conventional methods, but extra care must be taken because of its heat-affected zone and toughness. Preheat and inter-pass temperatures must be carefully controlled, and low hydrogen welding rods should be considered. Post-weld heat treatment may also be necessary to reduce the risk of hydrogen cracking.
Conclusion
To sum it up, AISI A514 Grade H Alloy Steel (UNS K11576) is an excellent material for manufacturing heavy-duty parts and equipment in various industries due to its exceptional properties such as high strength, toughness, weldability, and corrosion resistance. Care should be taken during the machining and welding of this steel, and heat treatment can be used to optimize its properties. A thorough understanding of this material’s composition and properties will help manufacturers and fabricators maximize its potential in their production processes.
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