Sep 27 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Cold Working
Annealing
Tempering
Introduction
Alloy steels are designated by AISI four-digit numbers. They are
more responsive to heat and mechanical treatments than carbon steels.
They comprise various types 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 more details about AISI 4815 alloy
steel, which can be heat treated to obtain good ductility and core
strength.
Chemical Composition
The chemical composition of AISI 4815 alloy steel is listed in the
following table.
| Element |
Content
(%) |
Iron, Fe
|
Balance
|
| Carbon, C |
0.13-0.18 |
| Manganese, Mn |
0.40-0.60 |
| Phosphorous, P |
0.035 (max) |
| Sulfur, S |
0.04 (max) |
| Silicon, Si |
0.15-0.30 |
| Nickel, Ni |
3.25-3.75 |
| Molybdenum, Mo |
0.20-0.30 |
Physical Properties
The following table shows the physical properties of AISI 4815 alloy
steel.
| Properties |
Metric |
Imperial |
| Density |
7.7 – 8.03 g/cm3 |
0.278 – 0.290 lb/in³ |
| Melting point |
1427ºC |
2600ºF |
Mechanical Properties
The mechanical properties of AISI 4815 alloy steel are outlined in
the following table.
| Properties |
Metric |
English |
| Elastic modulus |
190-210 GPa |
27557-30458 ksi |
| Poisson's ratio |
0.27-0.30 |
0.27-0.30 |
Other Designations
Other designations that are equivalent to AISI 4815 alloy steel
include the following:
- ASTM A29
- ASTM A322
- ASTM A331
- ASTM A519
- ASTM A752
- SAE J1397
- SAE J404
- SAE J412
- ASTM A505
- SAE J770
Fabrication and Heat Treatment
Machinability
AISI 4815 steel can be easily machined in annealed or normalized
conditions.
Forming
Forming of AISI 4815 steel can be performed using conventional
methods in annealed or normalized conditions.
Welding
AISI 4815 steel has welding property.
Heat Treatment
AISI 4815 steel is normalized at 927ºC (1700ºF) prior to heat
treatment. This steel is hardened or carburized at 927ºC (1700ºF) and
then oil quenched.
Forging
Forging of AISI 4815 steel is performed at temperatures ranging from
982 to 1177ºC (1800 to 2150ºF).
Cold Working
AISI 4815 steel can be easily cold worked using conventional methods
as the ductility of the steel is good in annealed or normalized
conditions.
Annealing
AISI 4815 steel can be annealed at 857ºC (1575ºF) and then slow
furnace cooled at a rate not more than 10ºC (50ºF) per hour followed by
air cooling.
Tempering
Tempering of AISI 4815 steel can be done at 149 to 649ºC (300 to
1200ºF).