S31254 тот баспайтын болат vs. S32205 тот баспайтын болат

1. Кіріспе

Corrosion-resistant alloys underpin critical infrastructure—from offshore platforms to chemical-processing plants.

Сервистік орта агрессивті өседі, selecting the right stainless grade proves vital.

Сондай-ақ, дуфлекс 2205 (UNS S32205) and super-austenitic 254 SMO (UNS S31254) occupy leading roles where chloride, acid or sour-gas attack threatens asset integrity.

, Сорт, this article delivers a professional, data-driven comparison of stainless steel S32205 vs S31254,

structured to guide engineers and specifiers through chemistry, Микроқұрылым, Механикалық қойылым, Коррозияның мінез-құлқы, дайындық, Термиялық өңдеу, қолданбалар, and relevant standards.

2. Химиялық құрамы & Микроқұрылым

Элемент	S32205 (2205)	S31254 (254 SMO)
Кр	22.0–23.0 wt%	20.0–22.0 wt%
-Да	4.5–6.5 wt%	17.0–19.0 wt%
Әзірлеу	2.5–3.5 wt%	6.0–7.0 wt%
N	0.08-0.20 Вт%	0.24–0.32 wt%
Друг	0.50 Еңбек	-
М.на	2.00 Еңбек	2.00 Еңбек
Жіне	1.00 Еңбек	1.00 Еңбек
Б	0.03 Еңбек	0.02 Еңбек

Сонымен қатар, S32205 exhibits a roughly 50/50 ferrite–austenite duplex microstructure, which confers high strength and good toughness.

Қайта, S31254 forms a fully austenitic matrix stabilized by its high nickel (≈18 wt%) және азот (дейін 0.32 wt%).

Болғандықтан, grain sizes in S31254 tend to remain uniform under heat, while 2205’s dual phases resist localized deformation.

Үстіне, S31254’s elevated molybdenum and nitrogen boost inclusion control and suppress sigma-phase formation, enhancing long-term corrosion resistance.

3. Механикалық қасиеттерді салыстыру

Мүлік	S32205	S31254
Бергі күш (Rp0.2)	~ 450 mPA	~300 MPa
Созылу күші (Шаққандағы)	~650 MPa	~650 MPa
Іуу (A%)	≥25 %	≥40 %
Ауданның қысқаруы (Z%)	≥50 %	≥60 %
Әсер ету қаттылық (Charpy V)	≥150 J @–40 °C	≥100 J @–20 °C
Тұрақты төзімділік	Дейін 300 °C service	Дейін 350 °C service

Бөлме температурасында, S32205 delivers superior yield strength—approximately 450 MPa versus S31254’s 300 MPa—thanks to its duplex phase hardening.

Дегенмен, both alloys reach similar tensile strengths (~650 MPa). Сонымен қатар, S31254 boasts higher ductility (40 % іуу) and reduction of area (60 %), which facilitate deep drawing and complex forming.

When operating at elevated temperatures, S31254 maintains creep resistance up to 350 ° °, while S32205 typically limits service to around 300 ° °.

Соңында, fatigue tests in chloride environments reveal comparable S–N curves, although S31254 shows a slight edge in high-cycle fatigue due to its homogeneous austenitic matrix.

4. Corrosion Resistance of S32205 vs. S31254

Corrosion Mode	S32205 (PREN ≈ 35)	S31254 (PREN ≈ 49)
Шоқы	Chloride threshold ~0.8 wt% NaCl	~3.5 wt% NaCl
Crevice	Байсалды	Үздік
Chloride SCC	50–60 °C	70–80 °C
General Acidic Corrosion (H₂so₄)	~10 mm/year @ 20 ° °	~2 mm/year @ 20 ° °
Oxidizing Acids (HNO₃)	Жақсы	Ең жақсы
Sulfide SCC (SSC)	Risk at H₂S > 1 төр	Minimal up to 5 bar H₂S

Because PREN (Pitting Resistance Equivalent Number = Cr + 3.3 Әзірлеу + 16 N) correlates with localized‐corrosion resistance, S31254 (PREN ≈ 49) outperforms S32205 (PREN ≈ 35).

, Сорт, S31254 tolerates chloride levels up to 3.5 wt% at ambient temperature without pitting, алақа 2205 caps out around 0.8 wt%.

Үстіне, S31254 resists chloride stress-corrosion cracking (Скр) дейін 80 ° °, салыстырғанда 60 °C for S32205.

Сонымен қатар, aggressive reducing acids (E.Г., 10 wt% H₂SO₄) corrode S32205 at ~10 mm/year, but only ~2 mm/year attacks S31254 under the same conditions.

Соңында, sour-gas tests reveal S31254’s superior performance in H₂S service up to 5 төр, while S32205 shows SSC susceptibility above 1 төр.

5. Дайындық & Weldability of S32205 vs. S31254

Аспект	S32205	S31254
Суық жұмыс	Дейін 30% thickness reduction	Дейін 50%
Min. Bend Radius	3 × thickness (duplex constraints)	2 × thickness
Weld Heat Input	0.5-1.5 kj / mm; risk of sigma phase if >2	1.0–2.5 kJ/mm; maintained austenite resists cracking
Post-Weld Annealing	1020 ° C 30 мин	1100 ° C 15 мин
Айналымдылық	40 - 50 % -ден 304 SS; tool wear moderate	30 - 40 % -ден 304 SS; tool wear higher

Іс жүзінде, S31254 tolerates more severe cold working—up to 50 % area reduction—due to its austenitic ductility, while S32205 work-hardens faster, limiting reduction to 30 %.

During bending, engineers maintain a minimum radius of 3 × thickness for 2205 to avoid ferrite cracking; қайта, S31254 allows tighter bends at 2 × thickness.

Дәнекерлеу 2205 requires heat inputs between 0.5 жіне 1.5 kJ/mm to preserve the duplex balance; excessive heat (>2 kj / mm) risks sigma-phase formation.

Сол уақытта, 254 SMO’s fully austenitic structure tolerates up to 2.5 kJ/mm without cracking.

Дәнекерлеуден кейін, 2205 benefits from solution annealing at 1020 ° C үшін 30 минуттары, whereas S31254 calls for 1100 ° C үшін 15 minutes to redissolve nitrides.

Соңында, machinability tests rank S32205 at 40–50% of 304 SS’s material-removal rate, while S31254 runs slightly slower (30-40%) and accelerates tool wear due to its high Mo content.

6. Comparison of Heat Treatment Methods

Емдеу	S32205	S31254
Шешім	1020 °C × 15–30 min → water quench	1100 °C × 10–20 min → water or air quench
Стрессті жеңілдету	600–650 °C × 1 н	650–700 °C × 1 н
Қартаю	Avoid above 300 ° ° (Фазалық тәуекел)	Тұрақты 400 ° °; limited aging

To restore the optimal duplex balance in S32205 after forming or welding, metallurgists perform solution annealing at 1020 °C for 15–30 minutes, followed by a water quench.

Қайта, S31254 requires a higher solution-anneal temperature of 1100 °C for 10–20 minutes, with either water or air quenching to retain its austenitic structure.

When stress relief proves necessary (E.Г., after heavy fabrication), 2205 demands 600–650 °C for one hour, while S31254 tolerates 650–700 °C without adverse phase changes.

Соңында, aging studies show that S32205 may form harmful sigma phase if held above 300 °C for prolonged periods, whereas S31254 remains stable up to 400 ° °, reducing the need for low-temperature stress-relief cycles.

7. Industry Applications of S32205 vs. S31254

Мұнай-химия & Теңіз платформалары:

Engineers specify S32205 for jackets and topsides when moderate chloride exposure and high strength matter.

Дегенмен, platforms facing severe splash-zone salinity lean on S31254’s superior pitting and SCC resistance.

Тұзсыздандыру қондырғылары & Seawater Handling:

In reverse-osmosis membranes and piping, S31254’s PREN (~49) withstands continuous contact with seawater (3.5 wt% NaCl), whereas S32205 (PREN ~35) functions best in feedwater stages with lower salinity.

Chemical-Processing Equipment:

Heat exchangers handling hot H₂SO₄ (10–20 wt%) favor S31254 for its low corrosion rates (~2 mm/year).

Керісінше, S32205 suits less aggressive services—such as brine coolers—where its higher strength reduces wall thickness.

Real-World Performance:

A North Sea platform retrofit replaced aged 2205 risers with 254 SMO, cutting pitting repairs by 80%.

Сол уақытта, a petrochemical plant reports five years of trouble-free service in 3 % HCl with duplex 2205 конденсфераторлар.

8. Reference Standards

• ASTM A240/A240M: “Standard Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and for General Applications”
• ASTM A182/A182M: “Standard Specification for Forged or Rolled Alloy- and Stainless Steel Pipe Flanges, Орталған арматура, and Valves and Parts for High-Temperature Service”
• UNS Designations: S32205 (дуфлекс 2205), S31254 (254 SMO)
• Nace mr0175 / iso 15156: “Materials for Use in H₂S-Containing Environments in Oil and Gas Production”

9. Балама бағалар

Below is a compiled list of common international equivalents for UNS S32205 (Дуфлекс 2205) and UNS S31254 (254 SMO), facilitating cross‐reference between major standards bodies.

Notes on Equivalents

• DIN Designation—for example, “1.4462” for 2205—appears alongside the steel’s chemical symbol (X2crnimon22-5-3), where “22-5-3” denotes nominal Cr-Ni-Mo-N levels.
• Афнор (French) grades use a Z-prefix: “Z3CN22-05-03” mirrors 2205’s 22 % Кр, 5 % -Да, 3 % Әзірлеу.
• Ол (Жапон) жіне Хост (Russian) designations reflect national numbering systems; the appended “L” in SUS329J4L indicates low-temperature impact toughness requirements.
• Chinese grades—0Cr22Ni5Mo3N and 0Cr25Ni20Mo3CuN—align closely with the UNS compositions, specifying carbon (0), хромий, никель, molybdenum and nitrogen content.

10. Comprehensive Comparison of S32205 vs. S31254

To bring all key differences into sharp relief, the table below summarizes chemistry, орындау, fabrication and cost metrics for UNS S32205 (Дуфлекс 2205) and UNS S31254 (254 SMO).

Критериция	S32205 (Дуфлекс 2205)	S31254 (254 SMO)
Phase Structure	~ 50 % феррит / 50 % ауулениттер	100 % аустениттік
Cr–Ni–Mo–N Chemistry	22 % Кр, 5 % -Да, 3 % Әзірлеу, 0.14 % N	20 % Кр, 18 % -Да, 6.5 % Әзірлеу, 0.28 % N
Орман	≈ 35	≈ 49
Бергі күш	450 МПа	300 МПа
Созылу күші	650 МПа	650 МПа
Іуу	25 %	40 %
Өмірлік қаттылық	≥ 150 J @ –40 °C	≥ 100 J @ –20 °C
Pitting Threshold	~ 0.8 % Торң у	~ 3.5 % Торң у
SCC кедергісі	≤ 60 ° °	≤ 80 ° °
Creep Service Limit	≤ 300 ° °	≤ 350 ° °
Cold-Work Limit	30 % thickness reduction	50 % thickness reduction
Weld Heat Input	0.5-1.5 kj / mm (avoid > 2.0)	1.0–2.5 kJ/mm
Шешім	1 020 °C × 15–30 min → water quench	1 100 °C × 10–20 min → water or air quench
Cost Index	1.0 (база)	~ 1.4 (≈ 40 % premium)

Негізгі жолдар:

1. Күш VS. Коррозия: S32205 delivers higher yield strength (≈ 450 МПа) және керемет қаттылық, making it ideal for load-bearing parts.
   Дегенмен, its pitting resistance (PREN ≈ 35) limits chloride service to ~ 0.8 % Торң у.
2. Керемет коррозияға төзімділік: S31254’s elevated Mo and N boost PREN to ≈ 49, tolerating seawater (3.5 % Торң у) and resisting SCC to 80 ° °, albeit at a 40 % higher material cost.
3. Жеңілдік: The fully austenitic S31254 supports deeper cold working (50 % кішірею) and wider welding windows (дейін 2.5 kj / mm),
   whereas the duplex grade requires more precise heat input to maintain its phase balance.
4. Жылу тұрақтылығы: You can run S31254 at moderately higher temperatures (дейін 350 ° °) without aging risks, while S32205 remains stable up to about 300 ° °.

11. Тұжырымдар

S32205 and S31254 each deliver distinct advantages. By understanding their chemistry, Микроқұрылым, Механикалық мінез-құлық, corrosion performance, fabrication nuances, and heat-treatment windows, engineers can make informed, authoritative decisions.

Осы Егер сізге сапалы қажеттілік қажет болса, сіздің өндіріс қажеттіліктеріңіз үшін тамаша таңдау Тот баспайтын болат құймалар.

Бүгін бізге хабарласыңыз!

 

ЖҚС

What primary factors govern the choice between S32205 vs S31254?

Іс жүзінде, engineers weigh strength versus corrosion resistance. S32205 delivers higher yield strength (~ 450 mPA) at a lower cost,

while S31254 offers superior pitting resistance (PREN ≈ 49) and chloride-SCC resistance to 80 ° °.

Can I cold-form S31254 more aggressively than S32205?

Иә. The fully austenitic structure of S31254 supports up to 50% thickness reduction, whereas S32205 work-hardens faster and typically limits cold reduction to 30% to avoid cracking.

What welding precautions apply to these grades?

For S32205, maintain heat input between 0.5-1.5 kj / mm and perform solution annealing at 1 020 °C to restore duplex balance.

Қайта, S31254 tolerates 1.0–2.5 kJ/mm and calls for a 1 100 °C solution‐anneal to redissolve nitrides.

Which alloy performs better in sour‐gas environments?

In H₂S service, S31254 resists sulfide stress-cracking up to about 5 төр, while S32205 shows SSC susceptibility above 1 төр.

Сондықтан, 254 SMO often becomes the preferred choice for sour-gas applications.