17-4 PH Stainless Steel Bars & Rods(AISI 17-4PH, SAE 17-4PH)

Product Description

1. Core Mechanical Properties & Heat Treatment (Conditions)

The unique advantage of 17-4 PH is that its mechanical properties can be precisely tailored using different aging temperatures (precipitation hardening). It is typically supplied in Condition A (Solution Annealed) and can then be heat-treated to various H-conditions.

⚠️ Machining Note: Condition A is highly martensitic and can be difficult to machine. It is often preferable to rough-machine the material in an overaged state (like H1150) or fully machine it in Condition A before final heat treatment, as the low-temperature aging process causes minimal dimensional distortion (typically <0.05%).

2. Chemical Composition (Weight %)

The inclusion of Copper (Cu) is what allows for precipitation hardening, forming intermetallic precipitates that block dislocations and increase strength.

• Chromium (Cr): 15.0 – 17.5% (Provides standard corrosion resistance similar to 304)

• Nickel (Ni): 3.0 – 5.0% (Stabilizes austenite during solution treatment)

• Copper (Cu): 3.0 – 5.0% (The primary precipitation hardening agent)

• Niobium + Tantalum (Nb + Ta): 0.15 – 0.45% (Grain refinement and carbide stabilization)

• Manganese (Mn): Max 1.0%

• Silicon (Si): Max 1.0%

• Carbon (C): Max 0.07%

3. Global Standard Equivalents

When cross-referencing across international material specifications, 17-4 PH corresponds to:

• UNS: S17400

• AISI / SAE: Grade 630 / 17-4PH

• EN / WNr: 1.4542 (X5CrNiCuNb16-4)

• AFNOR: Z6CNU17-04

• JIS: SUS630

• GOST: 07Kh16N4B (07Ð¥16Н4Б)

4. Corrosion Resistance

• General Performance: 17-4 PH behaves similarly to 304 stainless steel in most environments. It resists atmospheric corrosion and mild acids/alkalis better than standard hardenable martensitic steels (like the 400 series).

• Limitations: It is susceptible to pitting and crevice corrosion when exposed to stagnant seawater. For harsh marine or chloride-heavy environments, higher aging temperatures (e.g., H1150M) are utilized to improve resistance to Stress Corrosion Cracking (SCC), though this reduces overall strength.

5. Common Applications for Bars & Rods

Because of its high load-bearing capacity and resistance to environmental degradation, 17-4 PH round and hex bars are widely used for:

• Shafts & Rotors: Pump shafts, boat propeller shafts, and valve stems.

• Fasteners & Hardware: High-strength bolts, heavy-duty studs, clamping components, and specialized pins.

• Aerospace: Structural components, engine parts, and aircraft gears.

• Oil & Gas: Valve internals, gate valves, and offshore drilling equipment components.