17-4 - UNS S17400:

Type 17-4 is the most common grade of martensitic precipitation hardenable (PH) alloys. 17-4 provides an outstanding combination of high strength, good mechanical properties at temperatures up to 600°F (316°C), and short-duration, low-temperature heat treatments that minimize warpage and scaling. Its good corrosion resistance, formability and weldability make it ideal for a variety of applications in aerospace, petrochemical, and other structural applications. In the annealed condition 17-4 maintains high mechanical properties making some forming operations difficult.

Physical Properties:

• Melting Point: 2560 - 2625°F (1404 – 1440°C)
• Density: 0.282 lbs/in3 / 7.8 g/cm3
• Modulus of Elasticity in Tension: 28.5 X 106 psi / 197 GPa

Mechanical Properties:

Condition: Solution Treated (A)
• Tensile Strength Minimum (psi): 160,000
• Yield Strength Minimum 0.2% offset (psi): 145,000
• % Elongation in 2” Typical: 5%
• Hardness: Rockwell B85

Condition: Hardened + Aged (TH1050)
• Tensile Strength Typical (psi): 200,000
• Yield Strength Typical 2% offset (psi): 185,000
• % Elongation in 2": 8%
• Hardness: Rockwell C35

Condition: Aged (H1075)
• Tensile Strength Typical (psi): 175,000
• Yield Strength Typical 2% offset (psi): 165,000
• % Elongation in 2": 8%
• Hardness: Rockwell C37

Condition: Aged (H900)
• Tensile Strength Typical (psi): 210,000
• Yield Strength Typical 2% offset (psi): 200,000
• % Elongation in 2": 7%
• Hardness: Rockwell C45

Composition:

• Carbon: 0.07 max
• Manganese: 1.00 max
• Phosphorus: 0.040 max
• Sulfur: 0.030 max
• Silicon: 1.00 max
• Chromium: 15.00 - 17.50
• Nickel: 3.00 - 5.00
• Copper: 3.00 - 5.00
• Iron: Balance

Heat Treatments:

17-4 is typically supplied in Condition A, and can be heat treated at a variety of temperatures and times to achieve a wide range of properties. Below is a sampling of standard heat treatments for Condition A 17-4 material:

Condition	Heat To (+/- 15°F / 8.4°C)	Time at Temperature (h)
H900	900°F / 482°C	1
H1025	1025°F / 551°C	4
H1075	1075°F / 580°C	4

Corrosion Resistance:

Type 17-4 PH stainless steel withstands corrosive attack better than any of the standard hardenable (martensitic) stainless steels and is comparable to Type 304 in most media. The alloy exposed to seacoast atmosphere will gradually develop overall light rusting and pitting in all heat-treated conditions. In common with other stainless steels, 17-4 material is subject to crevice attack if exposed to stagnant seawater for any length of time.

OD (in.)	KVA STAINLESS MSS As-Welded Tube Capabilities In Inches
0.500
0.625
0.750
0.875
1.00
1.125
1.250
1.375
1.500
1.750
2.000
2.500
	0.016	0.020	0.024	0.028	0.031	0.035	0.039	0.043	0.047	0.051	0.055	0.059	0.063	0.067	0.071	0.075	0.079	0.098	0.110
Wall Thickness (in.)
				New Tooling Required								In House Tooling

OD (mm)	KVA STAINLESS MSS As-Welded Tube Capabilities In Millimeters
12.7
16.0
19.1
22.2
25.4
28.6
31.8
34.9
38.1
44.4
50.8
63.5
	0.40	0.50	0.60	0.70	0.80	0.90	1.00	1.10	1.20	1.30	1.40	1.50	1.60	1.70	1.80	1.90	2.00	2.50	2.75
Wall Thickness (mm)
				New Tooling Required								In House Tooling