Sep 13 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Hot Working
Cold Working
Annealing
Tempering
Hardening
Introduction
Alloy steels are designated by AISI four-digit numbers. They comprise different kinds of steels having compositions exceeding the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon steels.
AISI 4150 alloy steel is a higher carbon variation of chromium, manganese, molybdenum 4100 low alloy steel. The following datasheet gives an overview of AISI 4150 alloy steel.
Chemical Composition
The following table shows the chemical composition of AISI 4150 alloy steel.
|
Element |
Content (%) |
|
Iron, Fe |
96.745 - 97.67 |
|
Chromium, Cr |
0.800 - 1.10 |
|
Manganese, Mn |
0.750 - 1.00 |
|
Carbon, C |
0.480 - 0.530 |
|
Silicon, Si |
0.150 - 0.300 |
|
Molybdenum, Mo |
0.150 - 0.250 |
|
Sulfur, S |
0.0400 |
|
Phosphorous, P |
0.0350 |
Physical Properties
The physical properties of AISI 4150 alloy steel are given in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
7.85 g/cm3 |
0.284 lb/in³ |
|
Melting point |
1427°C |
2600°F |
Mechanical Properties
The following table outlines the mechanical properties of annealed AISI 4150 alloy steel.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
731 MPa |
106000 psi |
|
Yield strength |
380 MPa |
55100 psi |
|
Izod Impact |
24 J |
17.7 ft-lb |
|
Bulk modulus (typical for steel) |
140 GPa |
20300 ksi |
|
Shear modulus (typical for steel) |
80 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) |
20.20% |
20.20% |
|
Reduction of area |
40% |
40% |
|
Hardness, Brinell |
197 |
197 |
|
Hardness, Knoop (converted from Brinell hardness) |
219 |
219 |
|
Hardness, Rockwell B (converted from Brinell hardness) |
92 |
92 |
|
Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) |
13 |
13 |
|
Hardness, Vickers (converted from Brinell hardness) |
207 |
207 |
|
Machinability (annealed and cold drawn; based on AISI 1212 as 100 machinability) |
55 |
55 |
Thermal Properties
The thermal properties of AISI 4150 alloy steel are highlighted in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal conductivity (typical steel) |
44.5 W/mK |
309 BTU in/hr.ft².°F |
Other Designations
Other designations that are equivalent to AISI 4150 alloy steel include:
-
ASTM A29 (4150)
-
ASTM A322 (4150)
-
ASTM A331 (4150)
-
ASTM A519 (4150)
-
ASTM A711
-
ASTM A752 (4150)
-
MIL S-11595 (ORD4150)
-
SAE J1397 (4150)
-
SAE J404 (4150)
-
SAE J412 (4150)
Fabrication and Heat Treatment
Machinability
AISI 4150 alloy steel has good machinability in annealed or normalized conditions.
Forming
AISI 4150 alloy steel has good formability and ductility in the annealed condition.
Welding
AISI 4150 alloy steel can be welded using all conventional techniques. The mechanical properties of this steel can be affected if it is welded in the hardened condition. Post-weld heat treatment should be performed followed by an approved welding procedure
Heat Treatment
AISI 4150 alloy steel can be normalized at 899°C (1650°F) before heat treatment. It is then heated at 816°C (1500°F) followed by quenching in water in order to harden the steel.
Forging
AISI 4150 alloy steel is forged at 983 to 1205°C (1800 to 2200°F).
Hot Working
AISI 4150 alloy steel is hot worked at 872 to 1038°C (1600 to 1900°F)
Cold Working
AISI 4150 alloy steel is cold worked using conventional methods in the annealed condition.
Annealing
AISI 4150 alloy steel is annealed at 899°C (1650°F) followed by slowly cooling in the furnace.
Tempering
AISI 4150 alloy steel is tempered at 205 to 649°C (400 to 1200°F) based on the desired hardness level. The hardness of this steel can be reduced if the tempering temperature is higher.
Hardening
AISI 4150 alloy steel can be hardened by cold working or by heat treatment and tempering.