Project Description
14-5PH, commercially known as Carpenter Custom 450, NAS 450, or GTD 450, designated UNS S45000 and ASTM XM-25, is a martensitic age-hardenable stainless steel that achieves an exceptionally well-balanced combination of corrosion resistance approaching Type 304 and yield strength approximately three times that of standard 304—over 100 ksi (689 MPa) in the annealed (Condition A) state alone. Unlike 17-4PH, which typically requires aging to develop a stable microstructure, Custom 450 forms a stable low-carbon martensite directly from solution-annealing, allowing many components to be placed into service without post-fabrication heat treatment. A single-step aging treatment between 482°C and 621°C (900°F–1150°F) then develops higher strength levels—up to 1351 MPa (196 ksi)—while retaining excellent ductility and notch toughness. The alloy is covered under AMS 5763, AMS 5773, AMS 5863 (strip), ASTM A564/A693/A705 (XM-25), and ASTM A959. With its chromium content of 14–16%, deliberate additions of molybdenum (0.5–1.0%) for pitting resistance, and copper-niobium precipitation hardening, 14-5PH is widely specified in the oil & gas, chemical processing, power generation, marine, aerospace, and medical sectors.
14-5PH / Custom 450 / S45000 — Overview
14-5PH (UNS S45000 / XM-25) occupies a unique position in the precipitation-hardening stainless portfolio: it is the alloy of choice when standard 304/316 austenitics lack the mechanical strength for a pressure-containing or load-bearing design, yet martensitic grades such as 410 and 420 lack sufficient corrosion resistance in chloride-bearing produced fluids or aggressive chemical environments. The alloy bridges this gap with corrosion resistance essentially equivalent to Type 304—verified in salt spray, pitting, and intergranular corrosion tests—while delivering annealed yield strength above 689 MPa. The strengthening mechanism relies on a martensitic matrix hardened by fine copper-rich precipitates and niobium carbonitrides during aging, yielding a material that is fully magnetic, weldable by common processes (GTAW, GMAW, resistance welding), and machinable in the annealed condition with noticeably lower work-hardening rate than 17-4PH—typically allowing 20–30% higher cutting speeds. SHUNFU METAL supplies 14-5PH bar stock under a comprehensive ISO 9001 and API Q1 quality management system. Every heat lot undergoes optical emission spectrometry (OES) for full chemistry verification, ultrasonic testing in accordance with AMS-STD-2154 to confirm internal soundness, macro-etch evaluation for freedom from harmful segregation, and mechanical testing at the certified aging condition against ASTM A564 and AMS 5763/5773 minimum requirements. Where additional cleanliness is required, ESR-remelted stock is available, enhancing transverse toughness and reducing inclusion stringer populations for critical rotating and pressure-boundary components.
14-5PH / S45000 — Equivalent Standards
| Standard | Specification | Grade / Designation |
|---|---|---|
| ASTM | A564 / A693 / A705 | XM-25 |
| AMS | 5763, 5773, 5863 | Custom 450 |
| UNS | — | S45000 |
| SAE / AISI | — | 14-5PH |
| EN | 10088-3 | 1.4594 / X5CrNiMoCuNb14-5 |
| DIN | EN 10088 | X5CrNiMoCuNb14-5 |
| GOST | — | 05Х15Н6М1Д2БФ |
| JIS | — | SUS 630J1 / SUS XM25 |
| GB | S51290 | 04Cr15Ni7Cu2MoNbVN |
| AFNOR | — | Z7CNU15-05 |
| ASTM | A959 | S45000 |
14-5PH / S45000 — Oil & Gas Applications
Valve Stems & Valve Bodies
Gate, globe, and ball valve stems requiring 304-grade corrosion resistance in produced water with CO2 and H2S, plus yield strength sufficient to prevent stem buckling under high actuator thrust loads. Bodies for small-bore instrument valves and chemical injection quills.
Pump Shafts & Rotors
Centrifugal pump shafts, positive-displacement pump rotors, and progressive-cavity pump drive shafts in chemical injection, produced-water transfer, and refinery services. The alloy’s high annealed strength resists shaft deflection under hydraulic radial loads.
Wellhead & Xmas Tree Components
Gate and seat rings, stem nuts, wear bushings, and lock-down screws in land and platform wellhead systems. Corrosion resistance withstands atmospheric exposure and wellbore fluids without protective coatings.
BOP & Pressure Control Equipment
Ram shafts, operating rods, bonnet studs, and hydraulic actuator pistons in blowout preventers. The combination of strength, corrosion resistance, and Charpy V-notch toughness (up to 132 J at H1150) supports safe operation in HSEC applications.
Downhole Completion Tools
Nipple profiles, sliding sleeves, packer mandrels, and setting-tool components for both conventional and intelligent completions. Good machinability and low distortion during aging make it suitable for close-tolerance downhole tooling.
High-Strength Fasteners
API flange studs and nuts, clamp-hub bolting, tensioner studs, and structural fasteners for topside and subsea modules. When aged to H1000+, the alloy avoids the hydrogen embrittlement risk associated with high-strength low-alloy steel bolting.
Chemical Injection & Metering Systems
Chemical injection quills, metering valve spindles, and dosing-pump internals handling methanol, corrosion inhibitors, scale inhibitors, and biocides. The 304-equivalent corrosion resistance ensures against pitting from aggressive chemical concentrates.
Subsea Hardware
Subsea tree connector pins, stab-plate alignment components, ROV-operable torque-tool drive shafts, and corrosion-resistant load pins. Molybdenum content (0.5–1.0%) enhances resistance to crevice corrosion in oxygen-depleted subsea environments.
Refinery & Petrochemical Equipment
Heat exchanger tie-rods, compressor valve plates, pump wear rings, and tray hardware in sour-water strippers and amine units. Resistance to ammonium bisulfide and organic acid corrosion extends service intervals versus standard martensitic stainlesses.
14-5PH / S45000 Bar Stock — Availability from SHUNFU METAL
Hot Rolled Round Bar
Diameter 8 mm – 160 mm (0.31″ – 6.30″), length 3,000 – 6,000 mm. Supplied in solution-annealed (Condition A) or aged to order (H900–H1150). Surface: hot-rolled black, rough-turned, or peeled & polished. Typical stock range: 15–100 mm.
Hot Rolled Flat Bar
Thickness 6 mm – 80 mm, width 30 mm – 400 mm, length up to 6,000 mm. Suitable for machining into valve bodies, flanges, and structural brackets. Straightness tolerance ≤ 2 mm/m per ASTM A484.
Forged Round Bar
Diameter 100 mm – 600 mm (3.94″ – 23.62″), length up to 8,000 mm. Open-die forged from ESR/VAR ingot for large pump shafts, compressor rotors, and wellhead components. Forging reduction ratio ≥ 4:1 to ensure grain refinement and structural uniformity.
Forged Flat & Block
Thickness 30 mm – 300 mm, width 100 mm – 800 mm, length up to 5,000 mm. Forged flats and step-forged blocks for machined components. All forged stock supplied with full ultrasonic inspection to AMS-STD-2154 or EN 10228-3, SHUNFU METAL ISO 9001 / API Q1 certified.
14-5PH / S45000 — Chemical Composition
Chemical composition per AMS 5763 and ASTM A564 Grade XM-25 (weight percent, balance Fe). The alloy achieves precipitation-hardening response through the combined effect of copper—which forms fine, coherent Cu-rich BCC clusters that impede dislocation motion—and niobium, which precipitates as stable Nb(C,N) carbonitrides that refine grain size and contribute secondary strengthening. Molybdenum at 0.5–1.0% is deliberately retained to improve resistance to pitting and crevice corrosion in chloride-containing environments, a key differentiator from the leaner 17-4PH chemistry.
| Element | C | Mn | Si | P | S | Cr | Ni | Cu | Mo | Nb |
|---|---|---|---|---|---|---|---|---|---|---|
| Min | — | — | — | — | — | 14.00 | 5.00 | 1.25 | 0.50 | 8 × C |
| Max | 0.05 | 1.00 | 1.00 | 0.030 | 0.030 | 16.00 | 7.00 | 1.75 | 1.00 | — |
At SHUNFU METAL, every incoming heat undergoes full OES chemistry verification against the above AMS 5763 composition window before release to stock and further processing. The ISO 9001 and API Q1-certified quality system enforces full traceability from the mill certification through to dispatch, with each bar or forging individually identified by heat number. Positive material identification (PMI) using handheld XRF is performed on all shipments as a supplementary verification layer.
14-5PH / S45000 — Mechanical Properties
Room-temperature mechanical properties per AMS 5763 / ASTM A564 for 1.0-inch (25.4 mm) round bar. Solution annealing is performed at 1038°C ± 14°C (1900°F ± 25°F) for a time commensurate with section size, followed by rapid air or oil cooling to form a fully martensitic structure. Aging is conducted between 482°C and 621°C (900°F–1150°F) for 4 hours, air cooled. The Condition A (annealed) state already exceeds 100 ksi yield strength; for sour-service oil & gas applications requiring NACE MR0175 / ISO 15156 compliance, the H1150 condition (maximum hardness 28 HRC / 302 HBW) is the standard selection due to its resistance to sulfide stress cracking. SHUNFU METAL verifies tensile properties per ASTM A370 on samples from each heat-treatment lot, with Charpy V-notch impact testing conducted at −46°C for Arctic and subsea service qualification.
| Condition | YS 0.2% (ksi / MPa) | UTS (ksi / MPa) | Elong. (%) | RA (%) | Hardness (HRC) | Charpy V-Notch (ft-lb / J) |
|---|---|---|---|---|---|---|
| Condition A (Annealed) | 118 / 814 | 142 / 979 | 13 | 50 | 28 max. | 98 / 133 |
| H900 — Aged 482°C / 900°F | 188 / 1296 | 196 / 1351 | 14 | 56 | 42.5 | 40 / 54 |
| H950 — Aged 510°C / 950°F | 184 / 1269 | 187 / 1289 | 16 | 58 | 41.5 | 47 / 64 |
| H1000 — Aged 538°C / 1000°F | 169 / 1165 | 173 / 1193 | 17 | 63 | 39 | 51 / 69 |
| H1050 — Aged 566°C / 1050°F | 152 / 1048 | 160 / 1103 | 20 | 66 | 37 | 69 / 94 |
| H1150 — Aged 621°C / 1150°F | 92 / 634 | 142 / 979 | 23 | 69 | 28 | 97 / 132 |
NACE MR0175 / ISO 15156 compliance: In the H1150 condition, 14-5PH meets the maximum hardness criterion of HRC 33 (HBW 321) for sour service in H2S-containing environments. SHUNFU METAL can supply Charpy V-notch impact test reports at −46°C and NACE TM0177 sulfide stress cracking test certification upon request. The alloy also exhibits good elevated-temperature strength retention: at 300°C the yield strength remains approximately 690 MPa, making it viable for moderate-temperature refinery and power-generation applications where 304 would be structurally insufficient.