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1.4542 UNS S17400 630 17-4PH Precipitation Hardening Martensitic Stainless Steel

1.4542 UNS S17400 630 17-4PH Precipitation Hardening Martensitic Stainless Steel martensitic stainless steel 1.4542 UNS S17400 630 17-4PH Precipitation Hardening Martensitic Stainless Steel 1

1.4542 UNS S17400 630 17-4PH Precipitation Hardening Martensitic Stainless Steel


Alloy 17-4PH (UNS S17400), Type 630, is a chromium-nickel-copper precipitation hardening martensitic stainless steel with an addition of niobium. 17-4PH combines high strength and hardness with good corrosion resistance.
The alloy is furnished in the solution annealed condition (Condition A). It should not be used at temperatures above 572°F (300°C) or for cryogenic service. Optimal mechanical properties can be
obtained by subjecting the alloy to age hardening heat treatments. Heat treatment in the 900°F (482°C) range produces the highest strength.
The corrosion resistance of Alloy 17-4PH is comparable to 304 stainless steel in most environments,
and is generally superior to the 400 series stainless steels. It is used in applications where the combination of moderate corrosion resistance and unusually high strength are required.
Alloy 17-4PH can be easily welded and processed by standard shop fabrication practices.


• Aerospace  —  structural and parts
• Biomedical  —  hand tools
• Chemical Processing
• Food Process Equipment
• Gate Valves
• Mechanical Components
• Nuclear Waste Processing and Storage
• Oil and Gas Production  —  foils, helicopter deck platforms, etc.
• Pulp and Paper  —  paper mill equipment

Quality Standard:
ASTM A564 2004 Standard Specification for Hot Rolled and Cold Finished Age Hardening Stainless Steel Bars and Shapes
ASTM A705 Standard Specification for Age Hardening Stainless Steel Forgings

All Grades Comparison

1.4542 Grade 630(AMS 5604B) X5CrNiCuNb 16-4 S17400 Z5 17-4PH 0Cr17Ni4Cu4Nb

Chemical Composition(%)

C Si Mn P S Cr Ni Cu Nb
0.07 max 1.0 max 1.0 max 0.030 max 0.035 max 15.5-17.5 3.0-5.0 3.0-5.0 0.15-0.45

Mechanical Properties

Delivery Condition Electrical Resistivity(microhm-cm) Modulus of Elasticity(GPa) Modulus of Rigidity(GPa) Tensile Strength Rm (Mpa) Yield Strength Rp0.2 (Mpa) Elongation % in 2″ (50.8 mm) Reduction Of Area (%) Hardness (HRC)
A(annealed) 98 196 77.2 1030 min 760 min 8 / 33 max
H 900 77 196 77.2 1310 min 1170 min 10 40 40-47
H925 / / / 1170 min 1070 min 10 44 38-45
H1025 / / / 1070 min 1000 min 12 45 35-42
H1075 80 196 77.2 1000 min 860 min 13 45 31-39
H1150 86 196 77.2 930 min 725 min 16 50 28-37

Heat Treatment

Delivery Condition Heat to Time at Temperature Type of Cooling Density (g/cm3)
A(annealed) / / / 7.75
H 900 900°F ±10°F 60 min. ±5 min. Air 7.81
H925 925°F ±10°F 4 hrs. ±0.25 hrs. Air /
H1025 1025°F ±10°F 4 hrs. ±0.25 hrs. Air /
H1075 1075°F ±10°F 4 hrs. ±0.25 hrs. Air 7.83
H1150 1150°F ±10°F 4 hrs. ±0.25 hrs. Air 7.86


Solution treatment (Condition A):Grade 630 stainless steels are heated at 1040°C for 0.5 h, then air-cooled to 30°C. Small sections of these grades can be oil quenched.

Cold Working: Alloy 17-4PH has limited cold forming properties. Cold forming can only be undertaken on plates in the fully annealed condition. Stress corrosion resistance is enhanced by re-aging at the precipitation hardening temperature after cold working.

Hot Forming:Heat uniformly at 1742–2192°F (950–1200°C). A full solution anneal, cooling lower than 76°F (25°C) and aging at the required temperature must occur after
hot forming. The post forming heat treatment should be a function of the desired mechanical properties.
Annealing: 440C stainless steel is annealed at 843-871°C (1550-1600°F) followed by slowly cooling in the furnace.

Hardening: Grade 630 stainless steels are age-hardened at low temperatures to achieve the required mechanical properties. During the process, superficial discoloration occurs followed by shrinkage at 0.10% for condition H1150, and 0.05% for condition H900.

Welding: Alloy 17-4PH can be readily welded by most standard processes including SMAW, GTAW, PAW and GMAW.

Machinability: Alloy 17-4PH can be machined in both the solution treated and
precipitation hardened conditions. Machining characteristics may vary according to the hardness of the
metal. High speed tools are acceptable, but carbide tools are preferred. Standard lubrication should be used. Dimensional changes as a result heat treatment should be taken into account if very stringent tolerances are required.

Mill′s test certificate:

EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.