ThePipingMart Blog Grades HY-80 Alloy Steel – Composition, Properties, and Uses

HY-80 Alloy Steel – Composition, Properties, and Uses

HY80 Alloy Steel

Are you looking for high-strength steel that can withstand extreme pressures, temperatures, and corrosive environments? Look no further than HY80 Alloy Steel! This steel has been a go-to material for industries requiring robust and reliable metals, such as naval vessels, submarines, and pressure vessels. This ultimate guide deepens into HY80 Alloy Steel, its composition, mechanical and physical properties, uses heat treatment, machining, welding characteristics, and more. So let’s get started!

What is HY80 Alloy Steel?

HY80 Alloy Steel is a high-yield carbon steel alloy used for structural and ballistic applications. It combines excellent strength, toughness, weldability, and notch ductility, making it an ideal material for military-grade rifles and other high-demand applications requiring enhanced tensile strength.

HY-80 Steel Composition

HY80 Alloy Steel is a low-carbon, high-strength steel with various alloying elements to improve its mechanical and physical properties. It generally consists of 0.2% carbon, 1.65% manganese, 0.5% chromium, 0.3% molybdenum, 0.08% vanadium, 0.02% niobium, and 0.015% titanium. Adding these elements enhances the steel’s strength, toughness, and corrosion resistance while increasing its weldability and machinability.

Element Content (%)
Iron, Fe 93.1 – 96.4
Nickel, Ni 2.0 – 3.25
Chromium, Cr 1.0 – 1.80
Copper, Cu ≤ 0.25
Molybdenum, Mo 0.20 – 0.60
Silicon, Si 0.15 – 0.35
Carbon, C 0.12 – 0.18
Manganese, Mn 0.10 – 0.40
Phosphorous, P ≤ 0.025
Sulfur, S ≤ 0.025
Titanium, Ti ≤ 0.020
Vanadium, V ≤ 0.030

HY-80 Steel Mechanical Properties

HY80 Alloy Steel is renowned for its exceptional mechanical properties. It has a yield strength of 552 MPa, tensile strength of 690-895 MPa, and elongation of 15-20%, making it ideal for high-pressure applications. Additionally, it has a high fatigue strength, impact resistance, and ductility, making it a reliable material even in harsh conditions.

Properties Metric Imperial
Tensile strength, yield ≥ 552 MPa ≥ 80000 psi
Modulus of elasticity (typical of steel) 205 GPa 29700 ksi
Shear modulus (typical of steel) 80 GPa 11600 ksi
Poissons ratio (calculated) 0.28 0.28

HY-80 Steel Physical Properties

Besides its mechanical properties, HY80 Alloy Steel also boasts impressive physical properties. It has a density of 7.8 g/cm3, a thermal conductivity of 41 W/mK, a specific heat capacity of 450 J/kgK, and a coefficient of thermal expansion of 11.5-13.5 x 10-6/K. These properties make it suitable for high-temperature environments and applications requiring good thermal stability.

Properties Metric Imperial
Density 7.87 g/cc 0.284 lb/in³
Melting point 1424°C 2595°F

HY-80 Steel Equivalents

  • MIL S-16216
  • MIL S-21952

HY-80 Steel Uses

HY80 Alloy Steel is commonly used in various applications that require high strength and toughness, particularly in the military and defence sectors. Its primary use is in naval vessels and submarines, which are used for constructing pressure hulls, decking, and bulkheads. It is also utilized to build pressure vessels, offshore drilling rigs, and pipelines. It is also used in aeronautics for aircraft landing gear and wings.

HY-80 Steel Heat Treatment

Heat-treating HY-80 alloy steel requires a controlled heating and cooling process. The steel should be heated to 900 °C, then cooled slowly in an oven at 600 °C before tempering at different temperatures depending on the desired hardness of the resulting material. It is important to note that overheating during this process can lead to reduced strength and ductility in the alloy.

HY-80 Steel Corrosion Resistance

Additionally, HY80 Alloy Steel has good resistance to corrosion, particularly in seawater and other corrosive environments. It also exhibits high resistance to stress corrosion cracking and hydrogen embrittlement.

HY-80 Steel Welding

Welding HY80 Alloy Steel can be challenging due to its high hardenability and low carbon content. However, with the proper welding procedures and precautions, the steel can be welded without sacrificing its mechanical properties.

HY-80 Steel Machining

HY80 Alloy Steel is a high-strength, low-alloy steel that can be machined with conventional tools and processes. It offers superior toughness at cold temperatures and has excellent corrosion resistance, making it an ideal choice for aerospace parts and components. Coolants should be used to promote chip formation and reduce friction between the cutting tool and material to maximize performance in machining processes.


In conclusion, HY80 Alloy Steel is a high-strength and robust material widely used in various industries requiring reliable metals capable of withstanding extreme conditions. Its unique mechanical and physical properties and excellent corrosion resistance make it a go-to material for naval vessels, submarines, pressure vessels, offshore drilling rigs, and many other critical applications. So if you’re searching for a reliable metal that can handle any challenge, HY80 Alloy Steel should be at the top of your list!

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