13-8 stainless is a martensitic precipitation hardening stainless steel that has excellent strength, high hardness, superior toughness and good corrosion resistance. Good transverse toughness properties are achieved by tight chemical composition control, low carbon content, and vacuum melting. Typical applications are large airframe structural components and injection molding equipment.
Chemistry
|
|
Ni
|
Cr
|
Mo
|
C
|
P
|
S
|
Si
|
Mn
|
N
|
Al
|
Fe
|
|
MIN
|
7.5
|
12.25
|
2.0
|
-
|
-
|
-
|
-
|
-
|
-
|
0.90
|
-
|
|
MAX
|
8.5
|
13.25
|
2.5
|
0.05
|
0.01
|
0.008
|
0.1
|
0.2
|
0.1
|
1.35
|
Balance
|
Specifications
Inventory
13-8 PH Round Bar
Common Trade Names
13-8 Stainless
Features
· Martensitic, precipitation hardening (maraging) stainless steel.
Applications
· Aerospace components
· Injection molding equipment
· Components in the petrochemical and nuclear industries
Physical Properties
Density: 0.279 lb/inch3
Melting Range: 2560 - 2680°F
Electrical Resistivity: 613 Ohm-circ mil/ft
|
Temperature, °F
|
70
|
212
|
392
|
572
|
|
Coefficient of Thermal Expansion, in/in°F x 10-6
|
-
|
7.2
|
7.5
|
7.8
|
|
Thermal Conductivity
Btu • ft/ft2 • hr • °F
|
8.6
|
9.2
|
9.8
|
10.4
|
|
Modulus of Elasticity,
psi X 106
|
29.0
|
28.1
|
27.0
|
26.1
|
* 70°F to indicated temperature.
Mechanical Properties
Strength varies with heat treatment condition. The following table shows minimum mechanical properties for the various aged conditions, per AMS 5864.
|
|
H950
|
H1000
|
H1025
|
H1050
|
H1100
|
H1150
|
|
0.2 Offset Yield Strength, ksi
|
205
|
190
|
175
|
165
|
135
|
90
|
|
Ultimate Tensile Strength, ksi
|
220
|
205
|
185
|
175
|
150
|
135
|
|
Elongation in 2", %
|
10
|
10
|
11
|
12
|
14
|
14
|
|
Reduction of Area, % (Longitudinal)
|
45
|
50
|
50
|
50
|
50
|
50
|
|
Reduction of Area, % (Transverse)
|
45
|
50
|
50
|
50
|
50
|
50
|
|
Reduction of Area, % (Short-Transverse)
|
35
|
40
|
45
|
45
|
50
|
50
|
|
Min Hardness, Rockwell
|
45
|
43
|
-
|
40
|
34
|
30
|
Heat Treament
13-8 Stainless is available in the annealed condition, which is also called the solution heat treat condition or Condition A. Solution treat from 1675 - 1725°F for 15 to 30 minutes at temperature. Air cool or oil quench to below 60°F to effect complete transformation to martensite. Aging is normally carried out from 950 - 1150°F, depending on the desired final properties. Heat treatment is usually performed in air. Heat treatment of brazed components may be done in inert atmospheres. Reducing atmospheres should not be used because of the potential for nitrogen contamination.
|
Condition
|
H950
|
H1000
|
H1025
|
H1050
|
H1100
|
H1150
|
|
Temperature, °F
|
950±10
|
1000±10
|
1025±10
|
1050±10
|
1100±10
|
1150±10
|
|
Time, hours
|
4±0.25
|
4±0.25
|
4±0.25
|
4±0.25
|
4±0.25
|
4±0.25
|
