stainless steel 17-4 ph
QUALITY EXCELLENCE AWARD
UDYOG BHARATI AWARD
iso 9001: 2008 certified
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).
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
Offshore (foils, helicopter deck platforms, etc.)
Pulp and paper industry
Aerospace (turbine blades, etc.)
Nuclear waste casks
ASTM A693 grade 630 (AMS 5604B) UNS S17400
EURONORM 1.4542 X5CrNiCuNb 16-4
AFNOR Z5 CNU 17-4PH
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).
Allegheny Ludlum's AL 17-4™ Precipitation Hardening
Alloy (S17400), Type 630, is a chromium-nickel-copper
precipitation hardening stainless steel used for applications
requiring high strength and a moderate level of
corrosion resistance. High strength is maintained to approximately
The S17400 alloy is martensitic in structure in the annealed
condition and is further strengthened by a low
temperature treatment which precipitates a copper containing
phase in the alloy. In comparison to many alloys
in the precipitation hardening family, the S17400 alloy
requires a simple heat treatment; a one step process
conducted at a temperature in the range 900°F (482°C)
to 1150°F (621°C) depending on the combination of
strength and toughness desired. A wide range of properties
can be produced by this one step heat treatment.
Heat treatment in the 900°F (482°C) range produces
highest strength, although slightly less than that of alloys
like S17700 or S15700. The latter precipitation hardening
alloys generally require more steps to complete
FORMS AND CONDITIONS
The Allegheny Ludlum AL 17-4 Precipitation Hardening
Alloy is furnished as plate. Long products are produced
by Allvac, an Allegheny Technologies Company. In all
forms, the material is furnished in the annealed condition
Tests have shown that the corrosion resistance of
AL 17-4 Precipitation Hardening Alloy is comparable to
that of Type 304 stainless steel in most media. In general,
the corrosion resistance of AL 17-4 alloy is superior
to that of the hardenable 400 series stainless steels.
As with other precipitation hardening alloys, AL 17-4 Precipitation
Hardening Alloy is more susceptible to stress
corrosion cracking at peak strength. Consequently, in
applications in which chloride stress corrosion cracking
is a possibility, the material should be precipitation hardened
to produce the lowest hardness compatible with
the intended end use. This is done by heat treating at
the highest temperature which will produce suitable
Material in the annealed condition should not generally
be put into service. In this condition, the material has
an untempered martensite structure and is less ductile
than aged material. The untempered martensite may
be subject to unpredictable brittle fractures. In corrosive
environments, the untempered martensite is more
sensitive to embrittling phenomena such as hydrogen
embrittlement than material which has had one of the
AISI 630 AMS 5604 AMS 5622 AMS 5643 ASTM A564 (630) ASTM A693 (630) ASTM A705 (630) MIL C-24111 MIL P-47183 MIL S-81591 UNS S17400
15 - 17.5
3 - 5
3 - 5
0.15 - 0.45
0.15 - 0.45
Principal Design Features
One of the most widely used precipitation hardening grades in the business. While soft and ductile in the solution annealed condition, it is capable of high properties with a single precipitation or aging treatment. Characterized by good corrosion resistance, high harness, toughness and strength.
Commonly used in both aircraft and gas turbines, nuclear reactor, paper mill, oil field, and chemical process components.
Long, gummy chips characterize this alloys machinability. It can be machined in the annealed condition, however condition H1150M will yield best results. Post machining solution treatment of parts will be required prior to final hardening if machining in this condition.
This alloy is capable of being only mildly formed. If forming is required, do so in the overaged condition for best results.
Successfully welded by common fusion and resistance methods, this alloy should not be joined by oxyacetylene welding. AWS E/ER630 filler metal is recommended if required.
CONDITION A--Soak at 1900 F (1038 C) for 30 minutes and cool below 60 F (16 C) for complete martensite transformation. CONDITION H 950- Treat Condition A material at 900 F(482 C) for 1 hour, air cool.. CONDITION H925, H1025, H1075, H1100, H1150- Soak solution treated material for 4 hours at specified temperature, air cool, CONDITION H1150M- Soak solution treated material at 1400 F (760 C) for 2 hours, air cool, then re-heat to 1150 F (620 C) for 4 hours and air cool.
Soak for 1 hour at 2150 F (1177 C) prior to forging. Do not work below 1850 F (1010 C). Post-work solution treatment is required prior to final hardening.
17-4 PH can be easily hot worked using most of the common processes. It is suggested that material be solution treated at 1900 F(1038 C) then formed during cooling while the material is still austenitic. Post-work solution treatment is required prior to final hardening.
Despite its high initial yield strength, 17-4 can be cold worked successfully by most common methods.
1900 F (1038 C), hold for 1/2 hour, rapid cool.
This alloy has good ductility and may be readily formed by all conventional methods. Because the alloy is stronger than regular steel it requires more powerful equipment to accomplish forming. Heavy-duty lubricants should be used during cold forming.
Density (lb / cu. in.)
Specific Heat (Btu/lb/Deg F - [32-212 Deg F])
Electrical Resistivity (microhm-cm (at 68 Deg F))
MSO currently has no data available for this grade.