17-4PH Stainless Steel
17-4 Precipitation Hardening also known as Type 630 is a
chromium-copper precipitation hardening stainless steel used for
applications requiring high strength and a moderate level of
corrosion resistance. High strength is maintained to approximately
600 degrees Fahrenheit (316 degrees Celsius).
General Properties
Alloy 17-4 PH is a precipitation hardening martensitic stainless
steel with Cu and Nb/Cb additions. The grade combines high
strength, hardness (up to 572°F / 300°C), and corrosion resistance.
Mechanical properties can be optimized with heat treatment. Very
high yield strength up to 1100-1300 MPa (160-190 ksi) can be
achieved.
The grade should not be used at temperatures above 572°F (300°C) or
at very low temperatures. It has adequate resistance to atmospheric
corrosion or in diluted acids or salts where its corrosion
resistance is equivalent to Alloy 304 or 430.
| Applications | Standards |
- Offshore (foils, helicopter deck platforms, etc.)
- Food industry
- Pulp and paper industry
- Aerospace (turbine blades, etc.)
- Mechanical components
- Nuclear waste casks
| - ASTM A693 grade 630 (AMS 5604B) UNS S17400
- EURONORM 1.4542 X5CrNiCuNb 16-4
- AFNOR Z5 CNU 17-4PH
- DIN 1.4542
|
Corrosion Resistance
Alloy 17-4 PH withstands corrosive attacks better than any of the
standard hardenable stainless steels and is comparable to Alloy 304
in most media.
If there are potential risks of stress corrosion cracking, the
higher aging temperatures then must be selected over 1022°F
(550°C), preferably 1094°F (590°C). 1022°F (550°C) is the optimum
tempering temperature in chloride media.
1094°F (590°C) is the optimum tempering temperature in H2S media.
The alloy is subject to crevice or pitting attack if exposed to
stagnant seawater for any length of time.
It is corrosion resistant in some chemical, petroleum, paper, dairy
and food processing industries (equivalent to 304L grade).
If you would like to know more about 17-4PH stainless steel then
click 17-4PH Technical Data.
The properties mentioned below pertain to commonly available grade
630 bar products in ASTM A564. The specifications may not be
similar to other forms such as forgings and plates.
Composition Composition of 17-4PH stainless Steel
The compositional ranges of grade 630 stainless steels are
displayed below:
| Grade | C | Mn | Si | P | S | Cr | Ni | Cu | Nb+Ta |
| 630 | min. max | - 0.07 | - 1 | - 1 | - 0.04 | - 0.030 | 15 17.5 | 3 5 | 3 5 | 0.15 0.45 |
