Introduction:

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.

Applications:

• 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

DIN:1.4542

ASTM:Grade 630(AMS 5604B)

EN:X5CrNiCuNb 16-4

UNS:S17400

AFNOR:Z5

CNU:14-4PH

Chemical Composition(%)

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

Mechanical Properties

Delivery Condition:A(annealed)

Electrical Resistivity(microhm-cm):98

Modulus of Elasticity(GPa):196

Tensile Strength Rm (Mpa):77.2

Yield Strength Rp0.2 (Mpa):1030min

Elongation % in 2″ (50.8 mm):760min

Elongation % in 2″ (50.8 mm):8

Hardness (HRC):33max

 

Delivery Condition:H900
Electrical Resistivity(microhm-cm):77
Modulus of Elasticity(GPa):196

Modulus of Rigidity(GPa):77.2
Tensile Strength Rm (Mpa):1310min
Yield Strength Rp0.2 (Mpa):1170min
Elongation % in 2″ (50.8 mm):10

Reduction Of Area (%): 40
Hardness (HRC): 40-47

 

Delivery Condition:H925
Tensile Strength Rm (Mpa):1170min
Yield Strength Rp0.2 (Mpa):1070min
Elongation % in 2″ (50.8 mm):10
Reduction Of Area (%): 55
Hardness (HRC):  38-45

 

Delivery Condition:H1025
Tensile Strength Rm (Mpa):1070min
Yield Strength Rp0.2 (Mpa):1000min
Elongation % in 2″ (50.8 mm):12
Reduction Of Area (%): 45
Hardness (HRC):  35-42

 

Delivery Condition:H1075
Electrical Resistivity(microhm-cm):80
Modulus of Elasticity(GPa):196
Modulus of Rigidity(GPa):77.2
Tensile Strength Rm (Mpa):1000min
Yield Strength Rp0.2 (Mpa):860min
Elongation % in 2″ (50.8 mm):13
Reduction Of Area (%): 45
Hardness (HRC):  31-39

 

Delivery Condition:H1150
Electrical Resistivity(microhm-cm):196
Modulus of Elasticity(GPa):77.2
Modulus of Rigidity(GPa):930min
Tensile Strength Rm (Mpa):930min
Yield Strength Rp0.2 (Mpa):725min
Elongation % in 2″ (50.8 mm):16
Reduction Of Area (%): 50
Hardness (HRC):  28-37

 

Heat treatment

Delivery Condition:A(annealed)
Density (g/cm3) :7.75

 

Delivery Condition:H900
Heat to:900°F ±10°F
Time at Temperature:60 min. ±5 min.
Type of Cooling:Air
Density (g/cm3): 7.81

 

Delivery Condition:H925
Heat to:925°F ±10°F
Time at Temperature:4 hrs. ±0.25 hrs.
Type of Cooling:Air

 

Delivery Condition:H1025
Heat to:1025°F ±10°F
Time at Temperature:4 hrs. ±0.25 hrs.
Type of Cooling:Air

Delivery Condition:H1075
Heat to:1075°F ±10°F
Time at Temperature:4 hrs. ±0.25 hrs.
Type of Cooling:Air
Density (g/cm3): 7.83

 

Delivery Condition:H1150
Heat to:1150°F ±10°F
Time at Temperature:4 hrs. ±0.25 hrs.
Type of Cooling:Air
Density (g/cm3): 7.86

 

 

HEAT TREATMENT and FABRICATION:

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.