Sep 26 2012
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
Tempering
Hardening
Introduction
Alloy steels are designated by AISI four-digit numbers and are more susceptible to heat and mechanical treatments than carbon steels. They comprise different kinds of steels having compositions which exceed the limitations of Va, Cr, Si, Ni, Mo, C and B in the carbon steels.
The following datasheet provides an overview of AISI 4620 alloy steel, which has good strength and toughness. AISI 4620 alloy steel can be heat treated to obtain high strength.
Chemical Composition
The chemical composition of AISI 4620 alloy steel is listed in the following table.
|
Element |
Content (%) |
|
Iron, Fe |
96.405 - 97.38 |
|
Nickel, Ni |
1.65 - 2 |
|
Manganese, Mn |
0.450 - 0.650 |
|
Molybdenum, Mo |
0.2 - 0.3 |
|
Carbon, C |
0.170 - 0.220 |
|
Silicon, Si |
0.150 - 0.350 |
|
Sulfur, S |
0.04 |
|
Phosphorous, P |
0.0350 |
Physical Properties
The following table shows the physical properties of AISI 4620 alloy steel.
|
Properties |
Metric |
Imperial |
|
Density |
7.85 g/cm3 |
0.284 lb/in3 |
|
Melting point |
1421°C |
2590°F |
Mechanical Properties
The mechanical properties of annealed AISI 4620 alloy steel are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength, ultimate |
510 MPa |
74000 psi |
|
Tensile strength, yield |
370 MPa |
53700 psi |
|
Modulus of elasticity |
190-210 GPa |
27557-30458 ksi |
|
Bulk modulus (typical for steel) |
140 GPa |
20300 ksi |
|
Shear modulus (typical for steel)) |
80 GPa |
11600 ksi |
|
Poissons ratio |
0.27-0.30 |
0.27-0.30 |
|
Elongation at break (in 50 mm) |
31.30% |
31.30% |
|
Reduction of area |
60.30% |
60.30% |
|
Hardness, Brinell |
149 |
149 |
|
Hardness, Knoop (converted from Brinell hardness) |
169 |
169 |
|
Hardness, Rockwell B |
80 |
80 |
|
Hardness, Vickers (converted from Brinell hardness) |
155 |
155 |
|
Machinability (hot rolled and cold drawn. Based on 100 machinability for AISI 1212 steel) |
65 |
65 |
Other Designations
Other designations that are equivalent to AISI 4620 alloy steel include the following:
-
AMS 6294
-
AMS 6294C
-
ASTM A29 (4620)
-
ASTM A322 (4620)
-
ASTM A331 (4620)
-
ASTM A505
-
ASTM A519 (4620)
-
ASTM A535 (4620)
-
ASTM A646 (4620-3)
-
ASTM A752 (4620)
-
ASTM A829
-
SAE J1397 (4620)
-
SAE J404 (4620)
-
SAE J412 (4620)
-
MIL SPEC MIL-S-7493 (A4620)
Fabrication and Heat Treatment
Machinability
AISI 4620 steel can be easily machined in annealed or normalized conditions.
Forming
Forming of AISI 4620 steel can be performed in annealed or normalized conditions.
Welding
AISI 4620 steel can be welded using conventional methods.
Heat Treatment
AISI 4620 steel can be heat treated at 843ºC (1550ºF) and oil quenched. This steel can be normalized at 927ºC (1700ºF) and then air cooled prior to heat treatment.
Forging
AISI 4620 steel can be forged at temperature ranging from 982 to 1232ºC (1800 to 2250ºF).
Hot Working
Hot working of AISI 4620 steel can be performed at 816 to 1038ºC (1500 to 1900ºF).
Cold Working
AISI 4815 steel can be cold worked in the annealed conditions using conventional methods.
Tempering
Tempering of AISI 4620 steel can be done at 204 to 704ºC (400 to 1300ºF) based on the desired strength levels.
Hardening
AISI 4620 steel can be hardened by heat treatment or cold working.