--- title: SA789 Duplex Stainless Steel Tube, S32205 / S31803 (2205) | Ameritube description: ASME SA789 2205 duplex stainless steel seamless and welded tube, UNS S32205 and S31803, from Ameritube, Hillsboro, Texas. Chloride stress cracking and offshore service. U-bends available. Request a quote. --- 100% Made in USA · Hillsboro, TexasISO 9001:2015 certified · [(254) 580-9888](tel:+12545809888) [![](https://ameritube.net/hs-fs/hubfs/raw_assets/public/ameritube-2026/images/logo.jpg?width=52&height=52&name=logo.jpg)AmeritubeCopper tube mill](https://ameritube.net/?hsLang=en) [Products](https://ameritube.net/products?hsLang=en)[Capabilities](https://ameritube.net/capabilities?hsLang=en)[Industries](https://ameritube.net/markets?hsLang=en)[Quality](https://ameritube.net/quality?hsLang=en)[Resources](https://ameritube.net/resources?hsLang=en)[Company](https://ameritube.net/company?hsLang=en) [Talk to the quote desk(254) 580-9888](tel:+12545809888)[Request a quote](https://ameritube.net/request-a-quote?hsLang=en) [tel:+12545809888](tel:+12545809888) Menu - [Products](https://ameritube.net/products?hsLang=en) - [Capabilities](https://ameritube.net/capabilities?hsLang=en) - [Industries](https://ameritube.net/markets?hsLang=en) - [Quality](https://ameritube.net/quality?hsLang=en) - [Resources](https://ameritube.net/resources?hsLang=en) - [Company](https://ameritube.net/company?hsLang=en) - [Call the mill](tel:+12545809888)[Request a quote](https://ameritube.net/request-a-quote?hsLang=en) ![](https://ameritube.net/hs-fs/hubfs/new-site/cast/tube-stand-worker.jpg?length=960&name=tube-stand-worker.jpg) Products / Stainless & Duplex # SA789 duplex 2205, twice the strength, none of the chloride cracking. Half ferrite, half austenite. Duplex 2205 combines the chloride stress corrosion immunity of ferritic stainless with the toughness and weldability of austenitic, and it does it at roughly double the yield strength of 316L. The alloy that replaces 316L bundles that keep cracking. [Quote SA789 S32205 / S31803](https://ameritube.net/products/sa-789#quote) [Or call the quote desk(254) 580-9888](tel:+12545809888) SA789 S32205 / S31803 at a glance SourcedSupplied from qualified mills. Inspected, tested, and certified by Ameritube in Hillsboro, Texas 100%Eddy current tested before shipment SA789Supplied to ASME SA789, ASTM A789 MTRFull mill test report with every order **Alloy**SA789 S32205 / S31803 Duplex Stainless **Family**Stainless & Duplex **Supplied to**ASME SA789, ASTM A789 **Typical service**Chloride stress-cracking service, Offshore, Chemical process **Size range**1/2" to 3" OD, .049" to .220" wall, straight lengths and U-bends **Tempers**Solution annealed and quenched per SA789 **Testing**100% eddy current or ultrasonic per SA789, hydrostatic, flattening, flaring; ferrite count, ASTM A923 microstructure and impact tests, and G48 pitting test on request **Origin**Domestic and approved import mills, inspected and certified in Hillsboro **Sourced alloy, certified in Hillsboro**Ameritube does not manufacture SA789 S32205 / S31803 in Texas. It is supplied from qualified domestic and international mills, then received, inspected, tested, and released under our ISO 9001:2015 system in Hillsboro, Texas, with a full mill test report. ## What SA789 duplex is ASME SA789 covers seamless and welded ferritic-austenitic (duplex) stainless steel tube. Grade 2205, UNS S32205 or the older S31803 designation, is the workhorse: 22% chromium, 5% nickel, 3% molybdenum, and nitrogen, balanced to roughly 50/50 ferrite and austenite. That microstructure gives it a pitting resistance equivalent number around 35, immunity to chloride stress corrosion cracking in most service, and a yield strength of 65,000 psi minimum. ## Why it replaces 316L 316L bundles in warm chloride water fail by stress corrosion cracking, often within a few years. Duplex 2205 does not crack under those conditions, resists pitting better than 316L, and its higher strength allows thinner walls, which partly offsets the higher alloy cost. For Gulf Coast cooling water, offshore process, and produced water service, it is frequently the lowest life-cycle-cost option. ## Chemical composition, S32205 | Element | Requirement | | --- | --- | | Chromium | 22.0 to 23.0% | | Nickel | 4.5 to 6.5% | | Molybdenum | 3.0 to 3.5% | | Nitrogen | 0.14 to 0.20% | | Carbon | 0.030% max | ## Mechanical properties | Property | Minimum | | --- | --- | | Tensile strength | 95,000 psi (655 MPa) | | Yield strength | 65,000 psi (450 MPa) | | Elongation in 2" | 25% | | Hardness | 30.5 HRC max | ## Where it is used - Offshore platform and FPSO process coolers and produced water exchangers. - Refinery and petrochemical exchangers on brackish cooling water. - Chemical process heat exchangers in chlorides and organic acids. - Pulp and paper, desalination, and flue gas desulfurization. - Sour service under NACE MR0175 within its hardness and temperature limits. ## Case study Ameritube supplied duplex U-bend tube for a heat exchanger rebuild where 316L had cracked repeatedly. See the case studies PDF on the resources page for the details. **What to put in your SA789 S32205 / S31803 RFQ** S32205 or S31803 (S32205 is the tighter, preferred chemistry), seamless or welded, OD, wall, length or U-bend schedule, quantity, ferrite range, and any A923, G48, or NACE MR0175 requirement. U-bend heat treatment needs are important, state them. ### Documents - [Ameritube main brochure](https://ameritube.net/hubfs/PDFs/main_brochure.pdf?hsLang=en)PDF - [ISO 9001:2015 certificate](https://ameritube.net/hubfs/PDFs/ISO_CERT.pdf?hsLang=en)PDF ### Related alloys [C44300](https://ameritube.net/products/c44300-admiralty-brass?hsLang=en)[C70600](https://ameritube.net/products/c70600-copper-nickel-90-10?hsLang=en)[C71500](https://ameritube.net/products/c71500-copper-nickel-70-30?hsLang=en)[C72200](https://ameritube.net/products/c72200-copper-nickel-chromium?hsLang=en)[SA179](https://ameritube.net/products/sa-179?hsLang=en)[SA213 T5](https://ameritube.net/products/sa213-t5?hsLang=en) ### Industries [Marine & Defense](https://ameritube.net/markets/marine?hsLang=en)[Oil & Gas](https://ameritube.net/markets/oil-gas?hsLang=en)[Chemical Processing](https://ameritube.net/markets/chemical?hsLang=en) Alloy: SA789 S32205 / S31803 Duplex Stainless × Copper & Brass (Made in USA) **C12200**DHP Copper **C44300**Admiralty Brass **C70600**Copper Nickel 90/10 **C71500**Copper Nickel 70/30 **C72200**Copper Nickel Chromium Carbon & Alloy Steel **SA179**Seamless Carbon Steel **SA213 T2**Alloy Steel Boiler Tube **SA213 T5**Alloy Steel Boiler Tube **SA213 T9**Alloy Steel Boiler Tube **SA213 T11**Alloy Steel Boiler Tube **SA213 T12**Alloy Steel Boiler Tube **SA213 T22**Alloy Steel Boiler Tube Stainless & Duplex **TP304 / 304L**Stainless Steel **TP316 / 316L**Stainless Steel **TP321 / 321H**Stainless Steel **TP347 / 347H**Stainless Steel **SA268**Ferritic Stainless **SA249**Welded Stainless **SA789 S32205 / S31803**Duplex Stainless Nickel Alloys **Alloy 200**Nickel 200 (N02200) **Alloy 276**C-276 (N10276) **Monel 400**Nickel Copper (N04400) **Monel 405**Free-Machining Nickel Copper (N04405) **Alloy 600**Inconel 600 (N06600) **Alloy 625**Inconel 625 (N06625) **Alloy 800**Incoloy 800 (N08800) **Alloy 825**Incoloy 825 (N08825) Not sure? **Ask us**Describe the service and we will recommend the alloy No match. Pick "Ask us". **ISO 9001:2015**Bureau Veritas certified **Since 2004**Hillsboro, Texas 304L, 316L, or duplex 2205? Tap an alloy to open its page | Property | [TP304 / 304L](https://ameritube.net/products/sa-213-tp304?hsLang=en)Stainless Steel | [TP316 / 316L](https://ameritube.net/products/sa-213-tp316?hsLang=en)Stainless Steel | [SA789 S32205 / S31803](https://ameritube.net/products/sa-789?hsLang=en)Duplex Stainless | | --- | --- | --- | --- | | Molybdenum | None | 2 to 3% | 3 to 3.5% | | Chloride pitting resistance | Low | Moderate | High | | Chloride stress corrosion cracking | Susceptible | Susceptible | Resistant | | Yield strength | 25 ksi min | 25 ksi min | 65 ksi min | | Relative cost | Lowest | Higher | Higher, but thinner wall possible | | Typical pick | Fresh water, food, mild process | Brackish water, chemical process | Warm chlorides, offshore, where 316L cracked | Not sure? Put the service conditions in the quote notes and we will recommend the alloy. ### Have a spec? Send it. Alloy, OD, wall, length, quantity. An engineer on the Hillsboro quote desk answers within one business day. 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