Zanglamaydigan po'lat, ikki fazali
1.4501 S32760 (F55) Super Duplex
High performance duplex steel with additions of chromium, molybdenum, and nitrogen for enhanced pitting and crevice corrosion resistance.
Superduplex UNS S32760 (F55) combines the desirable aspects of both austenitic and ferritic grades and gives significant life cycle cost advantages when used in severe and corrosive conditions.
It has exceptional resistance to pitting, crevice corrosion and to stress corrosion cracking and have high strength combined weldability.
The higher chromium, molybdenum and nitrogen contents result in a Pitting Resistance Equivalent number (PREN) of >40, providing pitting and crevice corrosion resistance superior to austenitic and duplex stainless steels in almost all corrosive media. It also provides higher strength than both austenitic and 22% Cr duplex stainless steels.
PDFni yuklab oling
Dayoq
| Mahsulot shakli | Size Range |
| Dumaloq tayoqcha, po'stidan tozalangan K12 | 5⁄8" - 3" |
ILTIMOS, E'TIBORGA OLING
Agar siz izlayotgan narsani topa olmasangiz, iltimos, o'z… bilan bog'laning. Mahalliy xizmat markazi Sizning aniq talablaringizga muvofiq.
1.4501/S32760 Stainless Steel Related Specifications
| Tizim / Standart | Davlat / mintaqa | Sinf / Lavozim |
| Birlashgan Millatlar Tashkiloti | Xalqaro | S32760 |
| EN / W.Nr. | Yevropa | 1.4501 |
| EN Name (EN 10088) | Yevropa | X2CrNiMoCuWN25-7-4 |
| ASTM A240 | AQSh | S32760 (plate, sheet, strip) |
| ASTM A276 | AQSh | S32760 (bars, shapes) |
| ASTM A479 | AQSh | S32760 (bars for pressure) |
| ASTM A789 | AQSh | S32760 (seamless tubing) |
| ASTM A790 | AQSh | S32760 (seamless pipe) |
| ASTM A182 | AQSh | F55 (super duplex forging) |
| Savdo nomi | Xalqaro | Zeron 100 |
Xususiyatlari
Kimyoviy tarkib
1.4501/S32760 Steel
| Kimyoviy element | % Hozir |
| Karbon (C) | 0.00 - 0.03 |
| Xrom (Cr) | 24.00 - 26.00 |
| Marganets (Mn) | 0.00 - 1.00 |
| Silikon (Si) | 0.00 - 1.00 |
| Fosfor (P) | 0.00 - 0.03 |
| Olti (S) | 0.00 - 0.01 |
| Nikell (Ni) | 6.00 - 8.00 |
| Azot (N) | 0.20 - 0.30 |
| Mis (Cu) | 0.50 - 1.00 |
| Molibden (Mo) | 3.00 - 4.00 |
| Tungsten (W) | 0.50 - 1.00 |
| Temir (Fe) | Muvozanat |
Mexanik xususiyatlari
Bar & Section Up to 160mm Dia/Thickness
| Mexanik xususiyat | Qiymat |
| Cho'zilish A50 mm | 25 % |
| Brinell qattiqligi | 270 Maks HB |
| Cho'zilish mustahkamligi | 750 N/mm2 |
| 0.2% Proof Stress | 550 N/mm2 |
Umumiy jismoniy xususiyatlari
| Jismoniy xususiyat | Qiymat |
| Zichlik | 7.81 g/cm³ |
| Issiqlik kengayishi | 17.2 x10-6/K |
| Issiqlik o'tkazuvchanligi | 14.2 W/m.K |
| Elektrik qarshiligi | 0.8 x10-6 Ω .m |
Applications of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 (UNS S32760, often known by trade names like ZERON® 100) is a super duplex stainless steel with very high pitting resistance (PREN > 40), excellent resistance to chloride stress-corrosion cracking and yield strength roughly twice that of 304/316, making it ideal for highly aggressive chloride and mixed-process environments.
1. Offshore Oil & Gas and Subsea Production
Subsea manifolds, jumpers, flowlines and umbilical hardware exposed to cold, high-pressure seawater
Seawater injection systems, risers and topside process piping handling chlorides, CO₂ and small amounts of H₂S
Christmas trees, valves, connectors, hubs and fittings where both high strength and maximum localized-corrosion resistance are critical
2. Seawater Handling, Desalination and Marine Engineering
Seawater cooling-water systems: intake piping, pump casings, strainers and heat-exchanger components
Desalination plant high-load parts: high-pressure components, evaporator/RO hardware and brine-handling equipment
Highly exposed marine structures and hardware in splash/tidal zones where 316/2205 may pit or crevice-corrode over time
3. Chemical, Petrochemical and Refining Service
Equipment handling hot chloride-bearing, acidic or mixed chloride/acid media where 316L/2205 are borderline
Reactors, columns, heat exchangers and transfer lines in aggressive brines, chlorinated process streams and certain organic acids
Critical components where both high mechanical load va top-end localized-corrosion resistance must be combined in one alloy
4. Pulp, Paper, Mining and Minerals Processing
Bleach plant equipment (towers, washers, filtrate lines) in very aggressive chloride + oxidizing conditions
Components in strong, hot liquors where pitting, crevice corrosion and stress-corrosion cracking are severe risks
Slurry piping, pumps, mixers and flotation/processing hardware in mining and mineral-processing plants handling abrasive, chloride-containing slurries
5. Power Generation and Other High-Load Corrosive Duties
Power-plant seawater cooling systems, condensers and high-load structural hardware in coastal installations
FGD (flue-gas desulfurization) equipment where chloride-contaminated condensates and high temperatures are present
High-strength fasteners, shafts, flanges and fittings that must withstand both high stress and very aggressive wet corrosion in industrial plants
Xulosa
1.4501 / S32760 super duplex stainless steel is chosen for the most aggressive chloride and mixed-process environments—offshore and subsea oil & gas, seawater and desalination systems, harsh chemical and pulp-and-paper service, mining slurries and power-generation cooling—whenever designers need superior pitting/crevice resistance and chloride SCC resistance, together with very high strength, beyond what 316L or even standard duplex grades like 2205 can reliably provide.
Characteristics of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 (UNS S32760, often known under trade names like ZERON 100) is a super duplex stainless steel with a duplex (austenite + ferrite) structure, very high pitting resistance va yield strength roughly twice that of 304/316, designed for the most aggressive chloride and mixed-process environments.
1. Super Duplex Microstructure and Alloy Design
Taxminan 50% ferrit / 50% austenit eritmada anellangan holatda.
High alloying levels (Cr, Mo, N, often W and Cu) give a very high pitting resistance compared with standard duplex (2205) and 300-series austenitic grades.
The duplex structure provides a balance of high strength, good toughness and excellent resistance to stress-corrosion cracking.
2. Very High Strength and Structural Efficiency
Yarim o'tkazgich kuchi odatda about twice that of 304L/316L and higher than standard duplex 2205.
Allows designers to use:
Thinner wall thicknesses in piping and vessels
Lighter, more compact sections in structural and mechanical components
This high strength is crucial offshore and subsea, where weight reduction and compact, high-load parts are valuable.
3. Outstanding Pitting and Crevice Corrosion Resistance
High Cr + Mo + N (and often W) give a very high PREN (pitting resistance number), comfortably above standard duplex and 316L.
A'lo darajadagi chidamlilikka teshiklanish va yoriqlarga hujum da:
Natural seawater (including warm, oxygenated conditions)
Concentrated brines and chlorinated waters
Aggressive chloride/acid mixtures found in chemical and oil & gas service
This makes S32760 a “go-to” grade where 316 or even 2205 cannot deliver sufficient localized-corrosion margin.
4. Excellent Resistance to Chloride Stress-Corrosion Cracking (SCC)
Duplex microstructure gives Xloridli SCC ga juda yuqori chidamlilik, even at elevated temperatures and stress levels where austenitic grades fail.
Particularly suited to:
Warm seawater and high-chloride cooling systems
Offshore production, injection and process lines under high pressure
This SCC resistance is a key reason for its widespread use in offshore, subsea and desalination equipment.
5. Erosion–Corrosion and Corrosion-Fatigue Performance
High strength plus robust passive film give good resistance to erosion–corrosion in high-velocity seawater and abrasive, chloride-containing slurries.
Duplex structure provides strong corrosion-fatigue resistance under combined cyclic loading and corrosive attack.
Well suited to pumps, valves, mixers, manifolds, risers and slurry-handling components in harsh service.
6. Toughness and Temperature Capability
Toughness is lower than austenitic 316, but high for such a highly alloyed, high-strength grade when microstructure is correct.
Performs well at typical offshore and subsea temperatures, including low-temperature seawater.
Like other duplex and super duplex grades, long exposure in certain intermediate/high temperature ranges can form embrittling intermetallic phases, so fabrication heat treatments and service temperatures must respect manufacturer limits.
7. Payvandlanish imkoniyati va ishlab chiqarishni ko'rib chiqish
Weldable, but must be welded using super duplex-specific procedures:
Carefully controlled heat input and interpass temperature
Super duplex or over-alloyed austenitic filler metals
Proper shielding and back purging to avoid oxidation and loss of corrosion resistance
Correct procedures produce welds with strength and corrosion resistance close to the base metal; poor procedures can lead to intermetallics, reduced toughness and much lower pitting resistance.
8. Mexanik va Fizik Xususiyatlarning Muvozanati
High elastic modulus and strength give excellent stiffness and load-carrying capacity.
Lower thermal expansion than austenitic grades improves dimensional stability in temperature-cycling service.
Ferrite phase makes the alloy magnetic in all conditions (unlike annealed 304/316).
Overall, S32760 offers a strong combination of mechanical strength, toughness, fatigue resistance and top-tier localized corrosion resistance.
Xulosa
1.4501 / S32760 is a super duplex stainless steel that combines a duplex microstructure, very high strength, outstanding pitting/crevice and chloride SCC resistance, good erosion–corrosion and corrosion-fatigue performance, and weldability with appropriate procedures—making it a premier choice for the most demanding offshore, subsea, seawater, chemical and mining environments where both mechanical load and extreme corrosion must be handled in a single material.
Qo'shimcha ma'lumot
Payvandlanuvchanlik
Weldability of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 (super duplex) is weldable, but it is much more sensitive than 304/316 or even 2205. To keep its very high strength and corrosion resistance, welding must follow strict super-duplex procedures for heat input, filler choice, shielding and post-weld cleaning.
1. Umumiy payvandlanish xususiyatlari
Can be welded with standard stainless processes, but:
Process window is narrow compared with austenitic and standard duplex grades.
Incorrect parameters quickly lead to intermetallic phases (sigma, chi) and loss of toughness and pitting resistance.
Super duplex welds must preserve:
A balanced ferrite–austenite ratio in weld metal and HAZ.
High korroziyaga chidamlilik va SCC resistance comparable to the base metal.
2. Mos payvandlash jarayonlari
Commonly used processes:
GTAW (TIG) – preferred for root passes and thin sections; excellent control.
GMAW (MIG/MAG) – for production welding of pipe, tube and plate.
SMAW (MMA) – for site work and repairs with super duplex electrodes.
FCAW – for shop fabrication using super duplex flux-cored wires.
Autogenous welding (no filler) is generally Tavsiya etilmaydi, except on very thin material, because filler composition is critical for phase balance and corrosion resistance.
3. To'ldiruvchi metallni tanlash
Ishlat matching or slightly over-alloyed super duplex fillers specifically intended for S32760-type alloys.
Filler must:
Ta'minlang PREN at least equal to, preferably higher than, the base metal.
Deliver a duplex weld metal with suitable ferrite–austenite balance after cooling.
In special cases, over-alloyed austenitic fillers may be used for dissimilar joints or to maximise toughness, but weld metal strength and corrosion resistance must still meet design requirements.
4. Isitish quvvati, oraliq harorat va sovutish
Tight control of heat input is critical:
Too low → excess ferrite, low toughness, reduced corrosion resistance.
Too high / too slow cooling → formation of sigma and other intermetallics, serious embrittlement and loss of pitting resistance.
An'anaviy amaliyot (kontseptsual jihatdan):
Keep heat input in a narrow, moderate band recommended for super duplex.
Chegara o'tish harorati (often quite low), and avoid heat build-up.
Allow welds to cool in still air; no water quenching.
The goal is a refined duplex microstructure in weld and HAZ with minimal harmful phases.
5. Weld Microstructure, Mechanical Properties and Corrosion Behaviour
Correctly welded S32760 joints can achieve:
Yuqori mustahkamlik close to the base metal.
Yaxshi Ta'sirga chidamlilik, including transverse toughness where required.
Pitting, crevice and SCC resistance comparable to the parent plate in seawater/brine service.
Poor welding practice leads to:
Ferrite-rich or intermetallic-containing welds/HAZ with low toughness.
Markedly reduced pitting resistance, often visible as early corrosion near the welds in seawater or brine.
6. Joint Design, Shielding and Post-Weld Cleaning
Birgalikda dizayn:
Avoid excessive restraint and sharp stress raisers at weld toes.
Ensure good access for torch/wire and for later cleaning and inspection.
Shielding / backing:
Use high-quality shielding and back purging (typically inert gas) on root passes to prevent oxidation and loss of corrosion resistance on the inside surface.
Post-weld cleaning:
Olib tashlash slag, spatter, heat tint and oxide scale by grinding, brushing or blasting.
Use suitable pickling and/or passivation to restore a clean, chromium-rich passive film on and near welds.
7. Payvandlashdan keyingi issiqlik ishlovi (PWHT)
In most cases, no PWHT is applied to S32760; properties are controlled by welding parameters, not by tempering afterwards.
Standard carbon-steel-type stress-relief cycles are mos emas and can promote intermetallics and embrittlement.
If any PWHT is specified, it must follow strict super duplex guidance from the material standard or mill; otherwise, it can severely damage toughness and corrosion resistance.
Xulosa
1.4501 / S32760 super duplex stainless steel is weldable, but only with carefully controlled super-duplex procedures: use appropriate super duplex fillers, keep heat input and interpass temperature within a very narrow window, ensure excellent shielding and back purging, and thoroughly clean and passivate welds to maintain the alloy’s very high strength, toughness and top-tier pitting/SCC resistance in seawater, brines and other aggressive environments.
Yasalishi
Fabrication of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 is a super duplex stainless steel with very high strength and top-tier corrosion resistance. It can be fabricated successfully, but the process window is tighter than for 304/316 or even 2205, so forming, welding and heat input must be carefully controlled.
1. Umumiy tayyorlash yondashuvi
Asosan ...da yetkazib beriladi echimda pishirilgan va kislotada yuvilgan condition (plate, pipe, tube, bar, forgings).
Ko'pchilik shakllantirish, ishlov berish va payvandlash Bu sharoitda bajarilishi kerak.
Very high yield strength means:
Yuqori shakllantirish va kesish kuchlari
More spring-back in bending/rolling
Planning must integrate:
Tuzilish ketma-ketligi
Weld sequence and access
Final tolerances, residual stresses and distortion control
2. Shakl berish va sovuq ishlash
Cold formability is lower than 304/316 and standard duplex 2205, but still adequate for:
Rolling and bending of plate and sections
Forming shells, cones, heads and moderate profiles
Yaxshi amaliyot:
Ishlat katlanish radiuslari kattaroq Chegara yoriqlarining paydo bo'lishini oldini olish uchun 304/316 ni afzal ko'rish.
Shaklni to'ldiring bosqichma-bosqich qadamlar with smooth tools and good lubrication to reduce galling.
Expect and compensate for increased spring-back.
Heavy cold work raises strength/hardness and introduces residual stresses; for critical parts in severe environments, very high cold strain should be followed by yechimlikda anelash.
3. Hot Working and Solution Annealing in the Route
Hot working (forging, hot bending) must follow super duplex temperature limits to avoid intermetallic phases.
Muhim issiq ishdan so'ng, bir full solution anneal + rapid cooling is typically required to:
Restore a balanced austenite–ferrite microstructure
Recover toughness and maximum pitting/SCC resistance
Components are normally put into service in the echimda qutqarilgan holat, with no additional PWHT after correct welding.
4. Ishlov berish
Machinability bu more demanding than 304/316 and 2205 because of higher strength and work-hardening.
Recommendations:
Ishlat rigid setups and carbide tooling designed for duplex/super duplex.
Ariza bering moderate cutting speeds and adequate feed to cut below any work-hardened layer.
Ishlat yetarli sovutish suyuqligi and good chip-breaking geometries.
An'anaviy yo'nalish:
Rough machining in the solution-annealed condition.
After all welding/straightening, apply light finishing cuts or grinding to reach final size and surface finish.
5. Welding as Part of Fabrication
S32760 is weldable, but welds must follow super duplex procedures (see Weldability section):
Tight control of issiqlik kirishi va o'tish harorati.
Correct super duplex filler metals.
High-quality shielding and back purging for roots.
Normally no PWHT is used; properties are controlled by welding parameters, not post-weld tempering.
6. Yuzani tozalash, pikllash va passivlashtirish
To achieve full corrosion performance, all fabricated surfaces and welds must be to'g'ri tozalangan:
Zavot, tomchilar va issiqlik tusini maydalash, cho'tka bilan tozalash yoki shvetsa usuli bilan olib tashlang.
Use suitable tuzlash (or high-quality mechanical cleaning) followed by passivatsiya.
Aim for smooth, defect-free surfaces, especially in seawater / brine / crevice-prone areas.
Poorly cleaned or heat-tinted areas will lose a large part of the alloy’s pitting and crevice resistance advantage.
7. Buzilish, qoldiq kuchlanishlar va o'lcham nazorati
High strength and lower thermal expansion than austenitics help dimensional stability, lekin:
Welding and heavy cold work still introduce significant residual stresses.
Practical measures:
Ishlat balanced weld sequences va yetarli jihozlash.
Avoid excessive local cold straightening in critical areas.
For precision parts, plan:
Form → Weld (with super duplex WPS) → Light straighten if needed → Finish machine / grind.
Xulosa
1.4501 / S32760 super duplex stainless steel can be fabricated successfully when treated as a very high-strength, narrow-window duplex alloy: do forming and machining mainly in the solution-annealed state, use super-duplex-qualified welding procedures, and always finish with thorough cleaning, pickling/passivation and light final machining or grinding to preserve its balanced duplex microstructure, very high strength and exceptional corrosion performance in the most aggressive environments.
Issiq ishlash
Hot Working of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 super duplex stainless steel can be hot worked successfully, but it has a narrow and critical temperature window. Correct hot-working practice is essential to avoid intermetallic phases and to maintain toughness and very high corrosion resistance.
1. Ishlash uchun tavsiya etilgan issiq ishlash harorati diapazoni
Typical hot-working / forging range is about 1100–1250°C.
Start deformation towards the upper part Eng yaxshi plastika uchun ushbu diapazondan.
Qil not work below roughly 1000°C – ductility drops rapidly and the risk of cracking increases.
Uzoq ushlab turishlardan qoching 800–1000°C region, where intermetallic phases (e.g. sigma) can form.
2. Isitish va zarb bilan ishlash amaliyoti
Heat slowly and uniformly through the full section before heavy deformation.
Ishlat substantial, well-controlled reductions per pass, not light tapping, to refine the grain structure.
Reheat when the workpiece temperature falls near the lower working limit – do not continue to work it “too cold”.
Avoid overheating or excessive soaking at maximum temperature to limit grain growth, scale formation and property loss.
3. Cooling After Hot Working and Solution Annealing
After forging or hot forming, allow the part to cool in harakatlanmayotgan havo down to a safe handling temperature.
For S32760, a full solution anneal after significant hot work is normally mandatory Optimal xususiyatlarni tiklash uchun:
Reheat to the specified solution-annealing range (per mill/specification).
To'liq ichki isitish uchun namlang.
Tez soviting (usually water quench, or very fast air for small/thin sections).
Qoching slow cooling through the 600–1000°C range, which promotes intermetallic phase formation and embrittlement.
4. Yuzaki o'lcham, ishlov berish uchun qo'shimcha hajm va tozalash
At hot-working temperatures, super duplex develops heavy oxide scale and may suffer some surface damage.
Leave sufficient machining/grinding uchun chegirma to remove scale and any decarburised or otherwise damaged surface layer.
After hot working and solution annealing, apply:
Mechanical cleaning (grinding, blasting, brushing) and/or
Pickling and passivation
to restore a clean metallic surface and full corrosion resistance.
5. Mikrotuzilishga va xususiyatlarga ta'siri
Correct hot working + solution annealing gives:
A fine, well-balanced austenite–ferrite (duplex) microstructure.
Yuqori tortish kuchi va yaxshi chidamlilik.
Maximum korrozion chuqurchalar, yoriqlar va SCC ga chidamlilik characteristic of super duplex.
Poor control (working too cold, overheating, slow cooling, long holds in mid-temperature ranges) can:
Meva-sabzavot Qalin donlar and reduced impact toughness.
Shakl sigma va boshqa intermetallik fazalar, severely degrading toughness and localized corrosion resistance.
6. Dizayn, buzilish va yoriqlar nazorati
Design preforms and forgings with:
Smooth transitions, generous radii and uniform section thickness where possible.
No sharp corners or abrupt thickness changes that concentrate stress during forging or cooling.
For long shafts, rings or complex shapes:
Use proper support and handling during hot work and cooling to minimise bending and distortion.
Zarb ishlari uchun tekshiring qatlamlar, bukilishlar va yuzadagi yoriqlar before investing in final heat treatment and machining.
Xulosa
Hot working of 1.4501 / S32760 super duplex stainless steel must be done in a controlled 1100–1250°C range, with substantial reductions, careful reheating, followed by obligatory solution annealing and rapid cooling plus thorough cleaning, to preserve a fine duplex microstructure, very high strength, and the exceptional corrosion resistance required in its typical offshore, subsea and other highly aggressive applications.
Issiqlikka chidamlilik
Heat Resistance of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 is a super duplex stainless steel designed primarily for high-strength service in aggressive, chloride-containing environments at low to moderately elevated temperatures, not as a high-temperature or creep-resistant alloy.
1. Tavsiya etilgan xizmat harorati diapazoni
Typically used from 0°C dan past haroratlar taxminan 250–300°C gacha uzluksiz xizmatda.
Within this range it retains:
Very high hosildorlik va tortish mustahkamligi compared with 304/316 and even 2205
Yaxshi bardoshlilik and excellent localized-corrosion resistance
Long-term operation significantly above this range is Tavsiya etilmaydi, especially in critical corrosive service.
2. Yuqori haroratlarda mustahkamlik va chidamlilik
As temperature increases:
Mahsuldorlik va tortish kuchi kamayadi, but remain high relative to standard stainless steels.
Charchoqqa chidamlilik drops with temperature and cyclic loading, as with all steels.
In its intended range, S32760 provides:
A very favourable mustahkamlik-og'irlik nisbati for pressure-containing and structural components
Yetarli Ta'sirga chidamlilik where fabrication and heat treatment have been properly controlled
3. Chloride Environments and SCC Behaviour at Elevated Temperature
A key advantage of super duplex S32760 is its very high resistance to chloride stress-corrosion cracking (SCC), even at elevated temperatures where 304/316 are vulnerable.
In hot seawater, warm brines and aggressive chloride process streams:
Austenitic 300-series grades may fail by SCC.
S32760 typically maintains integrity, provided design stresses and temperature remain within recommended limits.
This makes it particularly valuable in offshore, subsea, desalination and cooling-water systems operating at elevated but not extreme temperatures.
4. Microstructural Stability and Intermetallic Phases
Like all duplex and super duplex alloys, S32760 is sensitive to intermetallic phase formation (e.g. sigma, chi) and 475°C-turi bo'yicha mo'rtlashuv if held too long in certain temperature bands.
Extended exposure in intermediate/high ranges can:
Keskin kamaytirish Ta'sirga chidamlilik
Pastroq teshiklanish va yoriq korroziyasiga chidamlilik
Increase susceptibility to cracking under load
For this reason, continuous long-term service at elevated temperatures is limited, and fabrication heat cycles (welding, hot working, PWHT) must be carefully controlled.
5. Oxidation and Surface Behaviour
Chromium-rich composition gives yaxshi oksidlanishga chidamlilik in air and combustion-type atmospheres at moderate temperatures.
Short-term higher-temperature excursions (start-up, shutdown, cleaning cycles) are typically tolerable if total exposure time is limited.
Uchun true high-temperature or creep-critical service (e.g. furnace internals, continuous operation at very high temperatures), dedicated heat-resistant austenitic or nickel alloys are usually required instead of super duplex.
6. Yuqori haroratli xizmat uchun loyihalash ko'rib chiqishlari
Treat S32760 as a high-strength, corrosion-resistant alloy for moderate temperatures, not as a primary high-temperature material.
In design, you should:
Keep continuous operating temperatures within the recommended range (≈ up to 250–300°C).
Ishlat temperature-dependent allowable stresses reflecting strength loss with temperature.
Avoid geometries and conditions that create local hot spots or prolonged exposure in intermetallic-forming temperature ranges.
Combine material selection with good surface finish, strict welding procedures and suitable inspection intervals in hot, chloride-bearing service.
Xulosa
1.4501 / S32760 super duplex stainless steel offers reliable heat resistance and very high strength in aggressive, chloride-containing environments at low to moderately elevated temperatures, retaining superior SCC and localized-corrosion resistance compared with 304/316 and standard duplex grades; however, it is not intended for long-term high-temperature or creep-controlled service, where intermetallic phase formation and property degradation become significant risks and dedicated heat-resistant alloys are more appropriate.
Mashinaga ishlov berish imkoniyati
Machinability of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 super duplex stainless steel has relatively poor machinability compared with 304/316 and even 2205, mainly because of its very high strength, work hardening and tough duplex microstructure. It can still be machined successfully, but only with rigid setups, correct tooling and carefully chosen cutting data.
1. Umumiy ishlov berish xulq-atvori
Very high yield strength → high cutting forces and tool loads.
Work hardens if feeds are too light or tools are dull, making subsequent passes harder.
Chips are tough and continuous, and can be difficult to break if parameters and chip breakers are not optimised.
Overall machinability is more demanding than 304/316 and 2205, but acceptable for critical parts with proper planning.
2. Ishlov berish uchun afzal sharoit
Machine in the solution-annealed, pickled condition as supplied.
Avoid heavy cold work (severe forming/straightening) just before finish machining because it:
Increases surface hardness
Accelerates tool wear
Makes dimensional control more difficult
Typical route for precision parts:
Rough machine in solution-annealed condition → weld/form (if needed) → light straightening → finish machine / grind.
3. Tooling and Cutting Parameters
Ishlat high-quality carbide tooling designed for duplex / super duplex stainless steels.
Key points:
Positive or mildly positive rake geometry to reduce cutting forces.
Rigid toolholders and fixturing to minimise chatter.
Moderate cutting speeds, generally lower than for 304/316 and 2205.
Adequate feed and depth of cut to cut below any work-hardened layer.
Avoid very light “polishing” cuts that only rub the surface and cause rapid work hardening and tool wear.
4. Coolant and Chip Control
Super duplex generates considerable heat; coolant is essential:
Use abundant, well-directed cutting fluid/emulsion at the cutting zone.
For deep holes, ensure coolant reaches the tool tip and chips are flushed out.
S32760 tends to form Qattiq, uzluksiz chiplar:
Use inserts with effective chip breakers.
Adjust feed and depth of cut to promote reliable chip breaking.
Good chip control improves tool life, surface finish and process stability, especially in CNC production.
5. burg'ulash, taplash va ipga kesish
Drilling
Ishlat carbide or cobalt HSS drills with robust web and suitable point geometry.
Apply steady feed; avoid dwelling at the bottom to prevent work hardening.
For deep holes, use peck drilling with chip evacuation and strong coolant flow.
Tapping / Threading
Use premium, strong taps with generous lubrication and modest speed.
Expect high torque because of material strength; avoid shock loading.
For critical or large threads, ipli frezalash is often preferable to reduce risk of tap breakage and improve control of thread fit.
6. Surface Finish and Dimensional Control
With correct tooling and parameters, S32760 can achieve high-quality turned, milled and ground finishes suitable for sealing surfaces and precision fits.
For dimensional accuracy:
Ishlat rigid clamping and balanced machining (remove material symmetrically where possible).
Avoid local overheating during heavy cuts or grinding to prevent residual tensile stresses and minor distortion.
For slender parts, plan multiple lighter passes rather than one very heavy cut to maintain straightness.
Xulosa
1.4501 / S32760 super duplex stainless steel has difficult but manageable machinability: it requires rigid setups, duplex/super-duplex-rated carbide tooling, conservative cutting speeds with adequate feed, abundant coolant and good chip-breaking strategies, plus a sensible route of roughing in the solution-annealed condition and light finishing after fabrication, to achieve accurate dimensions, good tool life and high-quality surfaces on critical high-strength, corrosion-resistant components.
Korrozyonga chidamlilik
Corrosion Resistance of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 super duplex stainless steel has outstanding corrosion resistance, especially in seawater, high-chloride brines and aggressive mixed chloride/acid environments. Its Cr + Mo + N (+ often W, Cu) alloying gives it a very high pitting resistance well above 316L and 2205.
1. Umumiy korroziya xulq-atvori
A'lo darajadagi chidamlilikka uniform corrosion ko'plab sanoat, dengiz va jarayon muhitlarida.
Aniq ustun 304/316 and even to standard duplex grades such as 2205 in demanding chloride service.
Designed for long service life in seawater, brines and chloride-containing process streams where conventional stainless steels pit or crack.
2. Xloridli muhitda chuqurchali va yoriq korroziyasi
High levels of Cr, Mo, N and often W give S32760 a very high korroziyaga chidamlilik (PREN well above 40).
Provides:
A'lo darajadagi chidamlilikka pitting in natural and warm seawater.
Strong resistance to crevice corrosion under gaskets, deposits and tight joints, provided designs minimise stagnant crevices.
Widely used where 316L and even 2205 cannot provide sufficient margin against localized attack in seawater and concentrated brines.
3. Xlorid stress-korroziya yoriqlari (SCC)
Duplex microstructure gives Xloridli SCC ga juda yuqori chidamlilik, far superior to austenitic 304/316.
In hot, aerated chlorides (e.g. warm seawater, brackish process waters, chlorinated cooling water):
304/316 often suffer SCC under tensile stress.
S32760 normally remains crack-free within its recommended temperature and stress limits.
This SCC resistance is a key reason for its use in offshore, subsea, desalination and seawater-handling systems.
4. Kimyoviy va jarayon muhitlaridagi xulq-atvor
Good resistance in many acidic, alkaline and mixed media, especially where chlorides are present:
Aggressive bleach and oxidizing environments in pulp and paper plants.
Chloride-bearing process streams in chemical and petrochemical service.
Certain acid–chloride mixtures where 316L and 2205 are at or beyond their limits.
For extremely strong mineral acids or very reducing conditions, nickel alloys or high-molybdenum super-austenitics may still be required; S32760 is optimised for chloride-dominated environments.
5. Payvandlash, issiqlik ta'siri ostidagi zonalar va intermetallik fazalar
With correct super duplex welding procedures (controlled heat input, proper filler, limited interpass temperature), weld metal and HAZ can achieve corrosion resistance close to the base metal.
Noto'g'ri payvandlash amaliyoti quyidagilarga olib kelishi mumkin:
Leave welds ferrite-rich, reducing toughness and localized-corrosion resistance.
Shakl sigma va boshqa intermetallik fazalar in welds/HAZ, which sharply reduce pitting resistance and impact toughness.
For critical seawater/brine service, qualified WPS/PQR and strict QC around welding are essential to maintain the alloy’s corrosion performance.
6. Yuzani yakunlash, tozalash va dizayn effektlari
As with all stainless steels, corrosion resistance depends strongly on Yuzaning holati:
Remove weld scale, heat tint, slag and contamination by grinding or blasting.
Follow with appropriate pickling and/or passivation to restore a clean, chromium-rich passive film.
Smooth finishes (ground, brushed, polished) resist pitting and fouling better than rough or damaged surfaces.
Good design further improves performance:
Minimal qilish crevices, dead legs and dirt traps in seawater/brine systems.
Ensure proper drainage and access for inspection and cleaning.
Use compatible materials to avoid adverse galvanic couples in wet service.
Xulosa
1.4501 / S32760 super duplex stainless steel offers top-tier pitting and crevice-corrosion resistance, outstanding resistance to chloride SCC and excellent overall corrosion behaviour in seawater, brines and aggressive chloride-containing process environments; when it is correctly welded, properly cleaned and sensibly detailed, it provides a very robust, long-life solution where 304/316 and even 2205 cannot deliver enough corrosion margin.
Issiqlik bilan ishlov berish
Heat Treatment of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 is a super duplex stainless steel, and like other duplex alloys it is not hardened by quenching like martensitic steels. Heat treatment is mainly used to set and restore the correct duplex microstructure and to protect toughness and corrosion resistance by avoiding harmful intermetallic phases.
1. Umumiy issiqlik bilan ishlov berish xulq-atvori
Kuch ...dan keladi high alloy content + duplex (ferrite + austenite) structure, not from martensite.
The key treatment is solution annealing with rapid cooling.
Conventional low-temperature “tempering” or carbon-steel-type stress relief is mos emas and can damage properties.
Long exposure in certain intermediate temperature ranges can form sigma and other intermetallic phases, causing embrittlement and loss of corrosion resistance.
2. Solution Annealing (Primary Heat Treatment)
Maqsad
Qayta tiklang balanced austenite–ferrite microstructure issiq ishlashdan yoki og'ir sovuq ishdan keyin.
Zararli cho'kindilarni eriting va qayta tiklang toughness and top-tier pitting/SCC resistance.
Typical practice (conceptual)
Heat to a high-temperature solution-annealing range (super duplex band specified by the mill/standard).
Bo'lak to'liq ichkaridan isitilguncha yetarli vaqt ushlab turing.
Tez soviting – usually water quench (or very fast air for thin products) – to freeze in the desired duplex structure and avoid intermetallic formation.
After correct solution annealing + rapid cooling, S32760 has:
Very high yield strength for a stainless steel.
Good impact toughness.
Maximum pitting, crevice and SCC resistance for this grade.
3. Stress Relief and Post-Weld Heat Treatment (PWHT)
Ko'pgina ilovalarda, no PWHT is performed; properties are controlled by the welding procedure, not by tempering after welding.
Standard carbon-steel-type stress-relief cycles (long holds in mid-temperature ranges) are dangerous for super duplex:
They can cause 475 °C embrittlement and form sigma/chi phases.
This severely reduces toughness and localized-corrosion resistance.
If any stress relief or PWHT is absolutely required by a code or client, it must:
Follow super-duplex-specific limits from the material standard or mill.
Be applied with strict control of temperature and time.
In practice, most components are used as-welded in the solution-annealed condition, with careful welding and thorough cleaning instead of PWHT.
4. Issiqlik bilan ishlov berishning mikrostrukturaga va xususiyatlarga ta'siri
To'g'ri yechim: anil + tez sovutish:
Produces a fine, balanced duplex structure.
Delivers very high strength with good toughness.
Restores maximum resistance to pitting, crevice corrosion and SCC.
Incorrect heat exposure (overheating, long holds, slow cooling in the 600–1000 °C range):
Promotes sigma va boshqa intermetallik fazalar.
Causes sharp drops in impact toughness.
Reduces resistance to localized corrosion, especially in seawater and brine.
Repeated uncontrolled heat cycles do not increase strength and can only damage the alloy’s mechanical and corrosion performance.
5. Practical Heat-Treatment Route in Fabrication
Typical route for critical S32760 parts:
Supply from mill in echimda pishirilgan va kislotada yuvilgan holat.
Hot working / heavy forming (if required) → followed by solution annealing + rapid cooling.
Cold forming, machining and welding with super-duplex procedures in the solution-annealed state.
No PWHT, only:
Proper weld procedure control (heat input, interpass, filler).
Thorough post-weld cleaning, pickling and passivation Toza passiv yuzani tiklash.
Xulosa
For 1.4501 / S32760 super duplex stainless steel, heat treatment is centred on high-temperature solution annealing followed by rapid cooling to obtain a fine, balanced duplex microstructure with very high strength and maximum corrosion resistance; routine stress relief or tempering cycles are avoided, and prolonged exposure in intermetallic-forming temperature ranges must be strictly prevented to keep toughness and pitting/SCC resistance at super-duplex levels.
Sovuq ishlash
Cold Working of 1.4501 / S32760 Super Duplex Stainless Steel
1.4501 / S32760 is a super duplex stainless steel with very high strength and limited ductility compared with 304/316 and even 2205. It can be cold worked, but only with sensible forming limits, generous radii and good process control.
1. Umumiy sovuq ishlanish qobiliyati
Ko'p higher yield strength and lower ductility than austenitic 304/316.
Cold work is more restricted than for 2205:
Suitable for moderate bending, rolling and profiling.
Not ideal for very severe deep drawing or tight-radius bends in thick sections.
Expect significantly higher forming loads and more spring-back.
2. Egish, aylantirish va shakllantirish mashqi
Ishlat katta minimal egilish radiuslari than for 304/316 and 2205 to avoid edge cracking.
Shaklni to'ldiring multiple, gradual steps rather than one heavy hit, especially on thicker plate.
Foydalanish:
Smooth, well-polished tools
Generous lubrication to reduce friction and galling
Good alignment and support to avoid local over-strain
Always allow for extra spring-back in tooling angles and roll settings.
3. Ish bilan qattiqlashtirish va qoldiq kuchlanishlar
S32760 work hardens strongly during cold deformation:
Deformed areas become harder, stronger and less ductile.
High residual stresses are introduced, which can affect fatigue and corrosion performance.
Heavy cold work may:
Make subsequent machining noticeably more difficult.
Increase distortion risk during and after welding.
For critical components in severe seawater or brine service, avoid very high local strain in highly stressed regions.
4. Heavy Cold Work and Solution Annealing
Uchun light to moderate forming (typical bends, rolling shells, cones, simple profiles):
Parts are often used without further heat treatment, provided welding procedures and cleaning are correct.
Uchun Qattiq sovuq ish, for example:
Tight-radius bends on thick plate
Heavy cold reduction in thickness or diameter
Large-area stretch forming or deep drawing
a full solution anneal + rapid cooling is normally recommended to:Restore a proper austenite–ferrite balance
Recover toughness and maximize pitting / crevice / SCC resistance
Remove the hard, highly strained structure created by heavy cold work.
5. Payvandlash va ishlov berish bilan o'zaro ta'sir
Sovuq ishlangan zonalar:
Are more susceptible to buzuqlik when welded due to stored strain energy.
May respond differently in the heat-affected zone if heavily work-hardened.
Practical sequence for precision/critical parts:
Form → Weld (with super duplex procedure) → Light straightening if needed → Finish machine / grind.This keeps cold strain moderate before welding and ensures final dimensional accuracy and surface quality.
6. Design Recommendations for Cold-Worked S32760 Components
Faraz qiling very high forming forces and ensure presses/rolls are capable.
Qaramaslik:
Sharp corners and very tight radii in highly loaded or seawater-exposed zones.
Local necking or severe thinning in critical areas.
For demanding offshore, subsea or desalination service:
Sovuqni saqlang o'rtacha va yaxshi taqsimlangan, not concentrated.
Consider solution annealing after extreme forming steps if maximum toughness and corrosion resistance are required.
Xulosa
Cold working of 1.4501 / S32760 super duplex stainless steel is possible but must be treated as high-strength, limited-ductility forming: use generous radii, gradual forming with good lubrication, expect high forming forces and spring-back, keep strains moderate in critical areas, and apply solution annealing after very heavy cold work to restore a balanced duplex microstructure and top-level toughness and corrosion resistance for severe seawater and high-chloride service.
