Aug 9 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Hot Working
Cold Working
Annealing
Tempering
Hardening
Applications
Introduction
Alloy steels are designated by AISI four-digit numbers. They are more responsive to mechanical and heat treatments than carbon steels. They comprise different types of steels with compositions which exceed the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va in the carbon steels.
The datasheet given below provides more details about HY80 alloy steel, which has good ductility and excellent notch toughness and weldability.
Chemical Composition
The chemical composition of HY80 alloy steel is listed in the following table.
|
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 |
Physical Properties
The following table shows the physical properties of HY80 alloy steel.
|
Properties |
Metric |
Imperial |
|
Density |
7.87 g/cc |
0.284 lb/in³ |
|
Melting point |
1424°C |
2595°F |
Mechanical Properties
The mechanical properties of HY80 alloy steel are outlined in the following table.
|
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 |
Other Designations
Other designations that are equivalent to HY80 alloy steel include the following:
Fabrication and Heat Treatment
Machinability
HY-80 steel can be machined in the quenched and tempered condition.
Forming
HY-80 may be readily cold or hot formed by conventional bending, or forming, processes.
Welding
HY-80 steel can be efficiently heated with metal-arc process using low hydrogen electrodes of type E-11018 or E-10018. HY 80 steel, except for heavy section, does not require pre-heating. Post-heating is not required.
Heat Treatment
Heat treatment is not required for HY-80 steel as it is supplied in quenched and tempered conditions. If necessary, it may be heated at 649°C (1200°F) for 1 h followed by slow furnace cooling and air cooling.
Forging
HY-80 alloy steel should not be reheated for forging as it is supplied in the heat treated and tempered condition.
Hot Working
Hot working of HY-80 steel can be performed at temperatures ranging between 93 and 316°C (200 and 600°F).
Cold Working
HY-80 steel can be cold worked using conventional methods.
Annealing
HY-80 steel can be annealed at 649°C (1200°F) and then furnace cooled at a temperature ranging from 93 to 260°C (200 to 500°F).
Tempering
HY-80 steel is tempered with 80 ksi minimum yield strength.
Hardening
HY-80 steel can be hardened by cold working.
Applications
HY-80 alloy steel is best suited for use in shipbuilding for welded hull plates.