Nitronic 50 (UNS S20910) - High Strength Austenitic Stainless Supplier of Bars, Forgings & Fasteners | Shanghai Hangbo Alloy Group
Date: 2026年8月7日 Categories: News Views: 222
By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360
Quick Answer: What Is Nitronic 50?
Nitronic 50 (UNS S20910 / XM-19 / W.Nr. 1.3964) is a nitrogen-strengthened high-strength austenitic stainless steel with 22% chromium, 12.5% nickel, 5% manganese, and 0.3% nitrogen that delivers approximately twice the yield strength of 316L (>=380 MPa vs 205 MPa) while remaining fully austenitic, non-magnetic, and ductile down to cryogenic temperatures. It is the standard choice for high-strength fasteners, pump shafts, marine hardware, and pulp & paper equipment where 316L lacks strength and duplex grades are overkill or unavailable. Shanghai Hangbo Alloy Group supplies Nitronic 50 as round bars, forgings, and fasteners.
Industry Pain Point: Pump shaft designers face a classic trade-off: 316L shafts (yield 205 MPa) must be oversized for high-torque service, adding weight and cost; duplex stainless (yield 450 MPa) offers strength but introduces pitting risk from the ferrite phase and requires careful fabrication. Nitronic 50 splits the difference perfectly -- 380 MPa minimum yield with fully austenitic structure, seawater-grade pitting resistance (PREN ~33), and galling resistance superior to both -- allowing shaft diameter reduction of 20-30% at the same torque capacity with zero fabrication premium.
Key Properties at a Glance
| Property | Value |
|---|---|
| UNS Number | S20910 |
| W.Nr. | 1.3964 |
| Alloy Family | Nitrogen-Strengthened Austenitic Stainless |
| Density | 7.88 g/cm3 |
| Melting Range | 1400-1450C |
| PREN | ~33 |
| Max Service Temp. | ~650C (continuous) |
| Yield Strength (Ann.) | >= 380 MPa (55 ksi) |
| Tensile Strength (Ann.) | >= 690 MPa (100 ksi) |
| Elongation (Ann.) | >= 35% |
| Key Standards | ASTM A276, A479, A240 |
Product Overview
Nitronic 50 is the flagship of the "Nitronic" family of nitrogen-strengthened stainless steels developed by Armco. The alloy's chemistry is a masterclass in nitrogen metallurgy: 0.20-0.40% nitrogen provides massive interstitial solid-solution strengthening (approximately 4.5x the strengthening efficiency of carbon, atom-for-atom), while 5% manganese maintains the austenitic structure that nitrogen would otherwise destabilize.
The result is an austenitic stainless that behaves like a precipitation-hardening grade at a fraction of the cost:
The Nitronic 50 value proposition:
- 2x yield strength of 316L (380 vs 205 MPa): Enables 20-30% smaller shaft diameters, thinner-wall pressure vessels, and stronger fasteners.
- Full austenitic stability: Unlike duplex (which contains ferrite), Nitronic 50 is single-phase FCC -- non-magnetic, immune to hydrogen embrittlement, and free of the 475C embrittlement window.
- Outstanding galling resistance: The high nitrogen content suppresses cold-welding between mating surfaces, making Nitronic 50 the standard for fasteners, valve stems, and pump shafts that must disassemble after years of service.
- Cryogenic toughness: Retains >150 J Charpy impact energy at -196C (liquid nitrogen temperature), with no ductile-to-brittle transition -- suitable for LNG and superconducting applications.
- PREN ~33: Superior to 316L (24) and comparable to 2205 duplex -- adequate for seawater and chloride service to moderate temperatures.
Shanghai Hangbo Alloy Group supplies Nitronic 50 as round bars, forgings, and fasteners (bolts, studs, nuts).
Executive Standards
| Product Form | ASTM | ASME |
|---|---|---|
| Bar & Rod | ASTM A276 / A479 | ASME SA-479 |
| Plate, Sheet & Strip | ASTM A240 | ASME SA-240 |
| Forgings | ASTM A182 Gr.FXM-19 / A473 | ASME SA-182 |
| Wire | ASTM A580 | -- |
| Fasteners | ASTM A453 Gr.651 | -- |
Chemical Composition (wt.%)
| Element | Min | Max | Role |
|---|---|---|---|
| Cr | 20.5 | 23.5 | Passive film; pitting resistance |
| Ni | 11.5 | 13.5 | Austenite stabilizer |
| Mn | 4.0 | 6.0 | Austenite stabilizer -- enables high N |
| Mo | 1.5 | 3.0 | Pitting/crevice resistance |
| N | 0.20 | 0.40 | Massive strength + PREN booster |
| Nb + V | 0.10 | 0.30 | Carbide stabilization; strength |
| Si | -- | 1.0 | Deoxidizer |
| C | -- | 0.06 | Ultra-low for weldability |
| S | -- | 0.030 | Impurity control |
| Fe | Balance | -- | Matrix |
PREN Calculation: PREN = Cr + 3.3xMo + 16xN = 20.5 + 3.3x1.5 + 16x0.20 = 28.4 minimum, typical 33-36.
Mechanical & Physical Properties
Room-Temperature (Solution-Annealed 1038-1093C/WQ)
| Property | Value |
|---|---|
| Tensile Strength | >= 690 MPa (100 ksi) |
| Yield Strength 0.2% | >= 380 MPa (55 ksi) |
| Elongation | >= 35% |
| Hardness | <= 100 HRB |
| Charpy-V Impact (-196C) | >= 150 J |
| Young's Modulus | ~196 GPa |
Elevated-Temperature (Typical)
| Temperature | Tensile (MPa) | Yield (MPa) |
|---|---|---|
| 20C | 800 | 450 |
| 300C | 620 | 330 |
| 500C | 520 | 280 |
| 650C | 380 | 220 |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.88 g/cm3 |
| Thermal Conductivity (20C) | ~14 W/m-K |
| Melting Range | 1400-1450C |
| Magnetic Permeability | <= 1.01 (non-magnetic) |
| Electrical Resistivity | ~0.80 micro-ohm-m |
Heat Treatment
Solution Annealing: 1038-1093C (1900-2000F), soak 30-60 min, water quench or rapid air cool. No precipitation hardening -- all strength is derived from nitrogen solid-solution strengthening.
Cold Working: Nitrogen-strengthened austenitic grades work-harden rapidly. Cold-drawn bar (approx. 15-20% reduction) can achieve yield strengths of 600-800 MPa.
Production Process
1. Round Bars
- Melting: AOD or VIM. Nitrogen added at the AOD stage with precise control (+/-0.02%). The nitrogen content is the single most important process variable.
- Hot Rolling: 1150-1200C, finishing >=950C, reduction >=4:1.
- Solution Anneal: 1038-1093C, WQ. Hardness <=100 HRB.
- Finishing: Peeled or ground surface. 100% UT for bars >=50mm. PMI every piece.
2. Forgings & Fasteners
- Forge: 1100-1150C, finishing >=950C.
- Solution Anneal: 1038-1093C, WQ.
- Machining: Nitronic 50 is "gummy" in the annealed condition -- use sharp carbide tools, reduced speeds, generous coolant.
- Cold Heading (Fasteners): Nitrogen-strengthened material cold-heads well; final cold work adds strength.
Industry Applications
| Industry | Component | Why Nitronic 50? |
|---|---|---|
| Marine | Pump shafts, propeller shafts, valve stems | 2x yield of 316L + seawater pitting resistance + galling resistance |
| Pulp & Paper | Blow tank agitators, digester valves, screw conveyors | Abrasion + corrosion + chloride environments |
| Petrochemical | High-pressure fasteners, valve trim | Strength retention to 650C + sour service |
| Nuclear | Reactor internals, spent fuel racks | Neutron-transparent (low Co) + cryogenic toughness |
| Cryogenics | LNG piping, superconducting magnet supports | No ductile-to-brittle transition; >150 J at -196C |
| Mining | Slurry pump components, screen plates | Abrasion resistance + corrosion |
Quality Assurance: 7-Stage
- Raw Material: FeCr, Ni, FeMnN analyzed by OES. Nitrogen content of FeMnN verified.
- AOD/VIM Melt: N +/-0.02%, Mo +/-0.15%, Cr +/-0.3% control.
- Hot Working: 1150-1200C, finishing >=950C, reduction >=4:1.
- Solution Anneal: 1038-1093C, WQ. Hardness verification.
- Mechanical Testing: Tensile per heat-treatment lot. Cryogenic Charpy on request.
- NDE: 100% UT bars >=50mm. PMI every piece.
- Documentation: EN 10204 3.1 MTC. SGS/TUV/BV witness.
Frequently Asked Questions
Q1: What is Nitronic 50 used for?
Marine pump shafts, high-strength fasteners, pulp & paper equipment, nuclear internals, cryogenic components, and valve trim -- anywhere 2x the yield strength of 316L with full austenitic properties is needed.
Q2: Nitronic 50 vs 316L?
Yield: 380 vs 205 MPa (2x). PREN: 33 vs 24. Galling resistance: far superior. Cost premium: 1.3-1.8x. Upgrade when strength or galling is the design limit.
Q3: Nitronic 50 vs 2205 duplex?
Nitronic 50: fully austenitic (non-magnetic, no H-embrittlement), yield 380 MPa. 2205: duplex (magnetic, 50% ferrite), yield 450 MPa. Choose 50 for non-magnetic or hydrogen service; 2205 for maximum strength.
Q4: Is it magnetic?
No -- fully austenitic, non-magnetic (mu-r <=1.01). Suitable for degaussing-sensitive and MRI-adjacent applications.
Q5: What is the yield strength?
>=380 MPa (55 ksi) annealed; 600-800 MPa in cold-worked condition.
Q6: Is it weldable?
Yes, with 316L-type filler or matching Nitronic 50 filler (ER209). Nitrogen retention in the weld is critical -- use N-bearing shielding gas.
Q7: Does it resist galling?
Yes -- outstanding galling resistance is a defining property, making it the standard for fasteners that must be disassembled.
Q8: What is the cryogenic toughness?
>150 J Charpy at -196C with no ductile-to-brittle transition.
Q9: What is the price?
$20-35/kg EXW. Contact sales@hangboalloy.com.
Q10: What product forms?
Bars (6-300mm), forgings, fasteners (ASTM A453 Gr.651), plate (A240), wire. SGS available.
Q11: What is the maximum service temperature?
~650C continuous. Above this, carbides precipitate and toughness degrades.
Q12: Does Shanghai Hangbo ship internationally?
Yes -- FOB/CIF/DAP to 40+ countries.
Q13: Why nitrogen at 0.3%?
Nitrogen provides ~4.5x the solid-solution strengthening of carbon, doubling yield strength while maintaining ductility and austenite stability.
Q14: What heat treatment?
Solution annealing at 1038-1093C, water quench. No aging.
Q15: Can it replace Inconel 625 in some applications?
For room-temperature to 300C corrosive service where strength is the limit, Nitronic 50 offers 90% of 625's capability at 30% of the cost. For high-temperature (600C+) or extreme chloride service, 625 remains necessary.
Contact Shanghai Hangbo Alloy Group
| Channel | Details |
|---|---|
| Company | Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier |
| Website | www.nickel-alloy.com |
| Email (Sales) | sales@hangboalloy.com |
| Email (Technical) | hangbo@nickel-alloy.com |
| WhatsApp (Lisa) | +86 13611656360 |
| Address | Room 1508, No. 288 Shiyi Road, Baoshan District, Shanghai 200940, China |
Shanghai Hangbo Alloy Group - Complete Product Range
| Family | Available Grades |
|---|---|
| Pure Nickel | NI200, NI201, N4, N5, N6 |
| Monel | 400, 401, 404, K-500, R-405 |
| Inconel | 600, 601, 617, 625, 690, 693, 718, X-750, 725 |
| Incoloy | 800, 800H, 800HT, 825, 925, 926, A-286, 25-6HN, 27-7MO |
| Hastelloy | C-276, C-22, C-2000, C-4, G-30, G-35, X, B-2, B-3, B-4, N |
| Super Austenitic | 904L, Alloy 28, Alloy 31, 254SMO |
| Chromium-Rich | Alloy 33 |
| High-Strength Stainless | Nitronic 50, PH13-8Mo |
| Nimonic | 75, 80A, 90, 95, 105, 115, 263 |
| Haynes | 25, 188, 214, 230, 242, 282, 556, HR-120, HR-160 |
| RA Series | RA330, RA333 |
| Precision | 1J22, 1J46, 1J50, 1J79, 1J85, 3J21, 4J32, 4J36, 4J45 |
| High-Strength | 18Ni250, 18Ni300, AerMet 100 |
| Heating | Cr20Ni80, Cr40Ni60 |
| Specialty | Alloy 20, Alloy 59, Inconel 686, 602CA |
Product Forms: Bars(6-500mm) | Tubes(OD 6-610mm) | Plates(0.1-100mm) | Forgings | Welded Pipes | Fittings | Wire(0.05-10mm) | Strip(0.02-4.0mm)
SGS/BV/TUV. Contact: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com
