17-4PH is a widely-used martensitic precipitation-hardening
stainless steel with a high concentration of chromium and nickel. It has many
favorable properties, including excellent strength, good corrosion resistance,
and excellent mechanical properties up to 600 °F (316 °C).
The alloy also possesses good toughness when welded, while short
low-temperature heat treatments reduce warping and scaling. Additionally,
17-4PH is easy to machine and fabricate.
Thanks to the beneficial properties, 17-4PH finds use in various
industries. Typical parts include mechanical seals, oil patch, and pump shafts.
Furthermore, the alloy also finds use in the aerospace industry,
petroleum industry, and chemical industry, food processing equipment, paper and
pulp industry, nuclear waste processing and storage, and general metalworking.
Anita
Steel & Metals offers Stainless Steel 17-4PH in two
sub-type specifications and multiple shapes/forms:
·
AMS 5604 (Plate, Sheet, and Strip)
·
AMS 5643 (Bar, Forging, Ring, Tubing, and
Wire)
Stainless
Steel 17-4PH Chemical Composition
|
Element
|
Min
(%)
|
Max
(%)
|
|
Carbon,
C
|
–
|
0.07
|
|
Manganese,
Mn
|
–
|
1
|
|
Silicon,
Si
|
–
|
1
|
|
Sulfur,
S
|
–
|
0.03
|
|
Phosphorus,
P
|
–
|
0.04
|
|
Chromium,
Cr
|
15
|
17.5
|
|
Niobium
+ Tantalum, Nb + Ta
|
0.15
|
0.45
|
|
Nickel,
Ni
|
3.0
|
5.0
|
|
Copper,
Cu
|
3.0
|
5.0
|
|
Iron,
Fe
|
–
|
*Balance
|
*Not exclusively to the element mentioned, but that one
predominates other elements that are used in smaller quantities.
Fabrication
and Working Instructions
Stainless Steel 17-4PH reacts best to hot forming at 1742 to 2192
°F (950 to 1200 °C), with annealing at 76 °F (25 °C) and aging. The alloy can
also be cold-formed in limited form, primarily to plates in the annealed
condition. However, stress corrosion resistance can be improved with re-aging.
Furthermore, 17-4PH can be cut using mechanical operations, such
as abrasive waterjets, machining, bandsaw, and shearing. However, plasma
cutting isn’t recommended on this alloy.
17-4PH has the best welding characteristics of competing stainless
steel alloys. Moreover, it can be welded using all standard techniques,
including gas tungsten arc, gas metal arc, shielded metal arc, and plasma arc.
To achieve desired mechanical properties, pre-weld and post-weld heat treatments
are recommended. For the best results, we recommend the AMS 5643 wire.
Physical
Properties of Stainless Steel 17-4PH
|
Property
|
Imperial
|
Metric
|
|
Melting
Range
|
2560-2625 °F
|
1404-1440 °C
|
|
Specific
Heat
|
0.11
Btu/lb.-°F
|
460
Joules/gg-K
|
|
Specific
Density
|
0.282 lb/in3
|
7.8 g/cm3
|
|
Electrical
Resistivity
|
38.6
µΩ in
|
98
µΩ cm
|
|
Linear
Coefficient of Thermal Expansion (70 °F to 200 °F) (21 °C to 93 °C)
|
6 [in/in/°F·106]
|
10.8 [μm/m·°C]
|
|
Linear
Coefficient of Thermal Expansion (70 °F to 400 °F) (21 °C to 204 °C)
|
6
[in/in/°F·106]
|
10.8
[μm/m·°C]
|
|
Linear
Coefficient of Thermal Expansion (70 °F to 600 °F) (27 °C to 316 °C)
|
6.2 [in/in/°F·106]
|
11.2 [μm/m·°C]
|
|
Linear
Coefficient of Thermal Expansion (70 °F to 800 °F) (21 °C to 427 °C)
|
6.3
[in/in/°F·106]
|
11.2
[μm/m·°C]
|
|
Thermal
Conductivity (@ 300 °F) (@ 149 °C)
|
124 Btu/(hr/ft²/in/°F)
|
17.9 [W/m-K]
|
|
Thermal
Conductivity (@ 500 °F) (@ 260 °C)
|
135
Btu/(hr/ft²/in/°F)
|
19.5
[W/m-K]
|
|
Thermal
Conductivity (@ 860 °F) (@ 460 °C)
|
156 Btu/(hr/ft²/in/°F)
|
22.5 [W/m-K]
|
|
Thermal
Conductivity (@ 900 °F) (@ 482 °C)
|
157
Btu/(hr/ft²/in/°F)
|
22.6
[W/m-K]
|
|
Poisson’s
Ratio (H900 Condition)
|
0.272
|
0.272
|
|
Modulus
of Elasticity (H900 Condition)
|
28
x 106 ksi
|
197
x 103 MPa
|
|
Modulus
of Rigidity in Torsion
|
9.68 x 103 ksi
|
67 x 103 MPa
|
Stainless Steel
17-4PH Mechanical Properties
|
Property
|
Imperial
|
Metric
|
|
Ultimate
Tensile Strength
|
23,300 psi
|
160 MPa
|
|
Yield
Strength (0.02%)
|
16,680
psi
|
115
MPa
|
|
Elongation
(% in 2’’)
|
5%
|
5%
|
|
Rockwell
Hardness C
|
35
|
35
|
Heat
Treatment
Stainless Steel 17-4PH is available in the solution annealed
condition at 1900 °F (1038 °C) and then air-cooled to 90 °F (32 °C).
However, additional heat treatments can produce various hardness
and toughness levels. The most common treatments are listed in the table below.
|
Condition
|
Temperature
[± 15 °F (± 8.4 °C)]
|
Cooling
Method and Duration
|
|
H 900
|
900 °F (482 °C)
|
Air cooling for 1 hour
|
|
H 925
|
925
°F (496 °C)
|
Air
cooling for 4 hours
|
|
H
1025
|
1025 °F (551 °C)
|
Air cooling for 4 hours
|
|
H
1075
|
1075
°F (580 °C)
|
Air
cooling for 4 hours
|
|
H
1100
|
1100 °F (593 °C)
|
Air cooling for 4 hours
|
|
H
1150
|
1150
°F (621 °C)
|
Air
cooling for 4 hours
|
|
H
1150 + 1150
|
1150 °F (621 °C)
followed by
1150 °F (621 °C)
|
Air cooling for 4 hours
followed by
Air cooling for 4 hours
|
|
H
1150-M
|
1400
°F (760 °C)
followed by
1150 °F (621 °C)
|
Air
cooling for 2 hours
followed by
Air cooling for 4 hours
|
Select AMS
Number:
|
AMS
Number
|
Alloy
|
Type
|
UNS
|
Misc./Shape
|
|
AMS 5604
|
17-4PH
|
Stainless Steel
|
S17400
|
|
|
AMS
5604 Plate
|
17-4PH
|
Stainless
Steel
|
S17400
|
Plate
|
|
AMS
5604 Sheet
|
17-4PH
|
Stainless Steel
|
S17400
|
Sheet
|
|
AMS
5604 Strip
|
17-4PH
|
Stainless
Steel
|
S17400
|
Strip
|
|
AMS
5643
|
17-4PH
|
Stainless Steel
|
S17400
|
|
|
AMS
5643 Bar
|
17-4PH
|
Stainless
Steel
|
S17400
|
Bar
|
|
AMS
5643 Forging
|
17-4PH
|
Stainless Steel
|
S17400
|
Forging
|
|
AMS
5643 Ring
|
17-4PH
|
Stainless
Steel
|
S17400
|
Ring
|
|
AMS
5643 Tubing
|
17-4PH
|
Stainless Steel
|
S17400
|
Tubing
|
|
AMS
5643 Wire
|
17-4PH
|
Stainless
Steel
|
S17400
|
Wire
|
