Nedbørherding (Ph) rustfritt stål utgjør en distinkt klasse av høyytelsesmaterialer som kombinerer korrosjonsmotstanden til austenittiske rustfrie stål med styrken til martensittiske kvaliteter.
Blant dem, 15-5 rustfritt stål (DIN X4CrNiCuNb164) has emerged as a vital alloy in aerospace, medisinsk, and industrial engineering sectors due to its superior strength, seighet, og pålitelighet.
Originally developed as an improvement over the well-established 17-4 Ph (US S17400), 15-5 PH rustfritt stål (US S15500) was engineered to offer better transverse mechanical properties and greater compositional consistency.
Its name derives from its nominal composition—15% krom og 5% nikkel—with copper added for precipitation strengthening.
1. Hva er 15-5 Rustfritt stål?
15-5 rustfritt stål, also known by its Unified Numbering System (OSS) designation S15500, er en martensitic precipitation-hardening (Ph) rustfritt stål.
It is engineered to provide a combination of high strength, Utmerket seighet, og moderat korrosjonsmotstand.
The alloy is particularly valued for its consistent mechanical properties in both the longitudinal and transverse directions, which makes it ideal for high-reliability applications.
Sentrale egenskaper:
- Martensitic microstructure: Achieved through solution heat treatment followed by aging, resulting in high hardness and strength.
- Nedbør herding: Enhanced through the controlled addition of kopper, which forms fine precipitates during aging to increase strength without compromising toughness.
- Improved over 17-4 Ph: Developed as a modification of 17-4 Ph (S17400) rustfritt stål,
15-5 offers better transverse toughness and more uniform mechanical properties across large cross-sections due to reduced delta ferrite and improved composition control.
Classification:
- USAs betegnelse: S15500
- Materialtype: Martensitic precipitation-hardening stainless steel
2. Kjemisk sammensetning av 15-5 Rustfritt stål
The chemical composition of 15-5 rustfritt stål is carefully balanced to achieve its superior mechanical properties, Korrosjonsmotstand, and consistency across large cross-sections.
It is characterized by a combination of krom, nikkel, og kopper, with tight control over carbon and other residual elements to minimize impurities and enhance performance.
Typisk kjemisk sammensetning (Weight%):
| Element | Innhold (%) | Funksjon |
| Krom (Cr) | 14.0 - 15.5 | Provides corrosion resistance and contributes to hardenability |
| Nikkel (I) | 3.5 - 5.5 | Stabilizes the austenite phase, improves toughness and ductility |
| Kopper (Cu) | 2.5 - 4.5 | Forms precipitates during aging, significantly increases strength |
| Karbon (C) | ≤ 0.07 | Low content reduces risk of carbide precipitation, Forbedre seighet |
| Mangan (Mn) | ≤ 1.0 | Enhances hot working and improves deoxidation during steelmaking |
| Silisium (Og) | ≤ 1.0 | Deoxidizer during processing, minor effect on mechanical properties |
| Fosfor (P) | ≤ 0.04 (typical max) | Controlled to prevent embrittlement |
| Svovel (S) | ≤ 0.03 (typical max) | Minimally present, aids machinability in small quantities |
| Niobium (Nb) eller Columbium (Cb) | ≤ 0.45 | Fungerer som en kornraffiner, prevents grain growth during heat treatment |
| Stryke (Fe) | Balansere | Base metal |
Note: Actual composition may vary slightly by producer within the allowable specification ranges, especially to meet certain mechanical or corrosion resistance targets.
Role of Copper in Precipitation Strengthening
En av de definerende funksjonene i 15-5 stainless steel is its copper content, which plays a critical role in its precipitation-hardening mechanism.
Upon aging heat treatment (F.eks., H900 or H1025), finely dispersed copper-rich precipitates form within the martensitic matrix.
These particles impede dislocation motion, resulting in a significant increase in yield and tensile strength without severely compromising ductility.
3. Mekaniske egenskaper til 15-5 Rustfritt stål
15-5 rustfritt stål is highly regarded for its excellent Mekanisk styrke, seighet, og utmattelsesmotstand.
These properties are primarily developed through nedbør herding (aldersherding) following solution treatment.
By adjusting the aging temperature and time, the alloy can be tailored to meet specific application requirements.
| Eiendom | H900 | H1025 | H1075 | H1100 | H1150 | H1150m |
| Strekkfasthet (MPA) | ~1310 | ~1170 | ~ 1100 | ~1060 | ~1030 | ~1030 |
| Avkastningsstyrke 0.2% Offset (MPA) | ~1170 | ~ 1070 | ~ 1000 | ~950 | ~ 900 | ~ 930 |
| Forlengelse (%) | ~ 10 | ~ 14 | ~ 15 | ~ 16 | ~ 17 | ~16–18 |
| Hardhet (HRC) | 40–45 | 33–38 | 30–34 | 28–32 | 25–30 | 26–31 |
| Fracture Toughness K_IC (MPA√m)* | ~ 55 | ~65 | ~ 70 | ~72 | ~75 | ~75+ |
| Utmattelsesgrense (MPA)** | ~ 620 | ~540 | ~ 510 | ~490 | ~470 | ~ 460 |
4. Fysiske egenskaper til 15-5 Rustfritt stål
15-5 stainless steel exhibits a well-balanced set of Fysiske egenskaper that complement its high mechanical performance.
| Eiendom | Verdi | Notater |
| Tetthet | 7.78 g/cm³ | Slightly higher than austenitic grades due to martensitic structure |
| Smelteområde | 1390 - 1440 ° C. | Narrow melting range typical of stainless steels |
| Elastisitetsmodul | ~ 200 GPA | Høy stivhet; stable across common temperature ranges |
| Termisk konduktivitet | ~ 18 w/m · k AT 100 ° C. | Lavere enn karbonstål; affects heat transfer in thermal cycling parts |
| Spesifikk varmekapasitet | ~ 460 J/kg · k | Moderat; relevant for thermal fatigue and energy absorption |
| Elektrisk resistivitet | ~0.90 μΩ·m | Høyere enn karbonstål; useful in electrical isolation applications |
| Coefficient of Expansion | ~10.8 × 10⁻⁶ /°C (20–100 ° C.) | Lower than austenitic stainless (F.eks., 304), important for dimensional stability |
| Magnetisme | Magnetic in all conditions | På grunn av sin martensittiske struktur, remains magnetic even after aging |
5. Varmebehandling og aldring av 15-5 PH rustfritt stål
15 5 PH rustfritt stål derives its exceptional mechanical properties through a two-step Varmebehandlingsprosess: løsning annealing etterfulgt av nedbør herding (aldring).
This controlled sequence develops a fine dispersion of strengthening precipitates, particularly copper-rich phases, Innenfor martensittmatrisen.
Løsning annealing (Tilstand a)
Løsning annealing is the initial and essential heat treatment step for 15-5 rustfritt stål, ofte referert til som Tilstand a.
This process prepares the alloy for subsequent aging by dissolving existing precipitates and homogenizing its microstructure.
Prosessparametere
- Temperatur: Omtrent 1038° C. (1900° F.)
- Soaking Time: Vanligvis 30 til 60 minutter, depending on material thickness
- Kjølemetode: Vanligvis Luftkjøling eller oil quenching for tykkere seksjoner
Purpose and Effects
- Dissolution of Precipitates: Any copper- or carbide-based precipitates formed during prior processing are fully dissolved, resulting in a uniform solid solution.
- Austenitiserende: The steel is heated into the austenite phase field where the microstructure transforms to face-centered cubic (FCC) Austenitt.
- Martensitic Transformation on Cooling: Upon rapid cooling, a diffusionless transformation occurs, converting austenite into body-centered tetragonal (BCT) Martensite.
This martensitic matrix is the foundation for further precipitation hardening. - Homogenisering: Eliminates segregation and microstructural inconsistencies, ensuring consistent mechanical properties throughout the material.
- Prepares for Aging: Sets the stage for controlled precipitation of strengthening phases during subsequent aging treatments.
Nedbør herding (Aldring)
After solution treatment, aging is performed at various temperatures to tailor the final mechanical properties. The most common aging tempers are:
| Aging Condition | Temperatur (° C.) | Temperatur (° F.) | Varighet | Key Effects |
| H900 | 482 | 900 | 1 time | Maximum strength, redusert duktilitet |
| H1025 | 552 | 1025 | 4 timer | Balansert styrke og duktilitet |
| H1075 | 579 | 1075 | 4 timer | Slightly reduced strength, improved toughness |
| H1100 | 593 | 1100 | 4 timer | Increased ductility, better fracture toughness |
| H1150 | 621 | 1150 | 4 timer | Overaged for optimal toughness and stress relief |
| H1150m (Double Age) | 621 × 2 | 1150 × 2 | 4 + 4 timer | Highest toughness, Dimensjonell stabilitet |
Note: All aging is done in air; no quench is needed after aging.
6. Korrosjonsmotstand
15 - 5 stainless steel offers good corrosion resistance in atmospheric, Marine, og milde kjemiske miljøer.
Under normale atmosfæriske forhold, it can resist corrosion for long periods without significant degradation.
In marine environments, it can withstand the corrosive effects of saltwater spray and humidity better than many other martensitic stainless steels.
Compared to martensitic grades like 410 og 420, 15 - 5 stainless steel has better pitting and crevice corrosion resistance.
This is due to its chemical composition, which promotes the formation of a more stable and continuous passive film on the surface.
Imidlertid, 15 - 5 stainless steel is not ideal for chloride-rich or highly acidic environments.
In such conditions, austenitic stainless steels like 316L or duplex stainless steels like 2205 are more suitable, as they offer superior corrosion resistance.
7. Manufacturing Processes and Fabrication of 15-5 Rustfritt stål
Støping
15-5 stainless steel can be cast through various methods, inkludert Investeringsstøping og Sandstøping, each suited to different component requirements.
- Investering Casting is often favored for producing complex-shaped components with high dimensional accuracy and superior surface finish.
This process involves creating a wax pattern of the desired part, belegg det med et keramisk skall, then melting out the wax to form a cavity.
Molten 15-5 PH stainless steel is poured into this cavity to form precise, intrikate deler. - Sandstøping, omvendt, is better suited for larger, less complex components.
It is generally more cost-effective for producing sizable parts where tight tolerances and fine surface finishes are less critical.
Varmt og kaldt arbeid
In its glødet tilstand, 15 5 stainless steel exhibits good formability, allowing for a wide range of hot and cold working processes:
- Varmt arbeid: Techniques such as forging and rolling are performed at elevated temperatures (typically above 900°C).
This enables shaping the steel into various forms—bars, plater, and tubes—while refining the grain structure and enhancing mechanical properties. - Kaldt arbeid: Processes like cold rolling, tegning, and stamping enable precise dimensional control and improved surface finishes.
Imidlertid, cold working induces work hardening, which may necessitate subsequent annealing or stress-relief treatments to restore ductility and reduce internal stresses.
Maskinering
Maskinbarhet av 15 5 stainless steel is generally good in the Annealed (løsningsbehandlet) betingelse, but decreases significantly as the material is hardened through precipitation aging.
- To machine 15-5 effektivt, the use of carbide-tipped cutting tools is recommended due to their hardness and heat resistance.
- Employing Høyhastighets maskinering techniques helps minimize cutting forces and heat buildup.
- Adequate use of coolants and lubricants is essential to reduce tool wear and achieve superior surface finishes on machined parts.
Sveising
Sveising 15 5 stainless steel requires meticulous control to prevent issues such as cracking and degradation of mechanical properties.
- Forvarming the base metal to around 150–200 ° C. prior to welding helps minimize thermal stresses and reduce the risk of cracking.
- Depending on the welding method and application, en Etter sveis varmebehandling may be necessary to restore mechanical strength and relieve residual stresses.
- Selection of Fyllstoffmetaller that closely match the chemical composition of stainless steel is critical for ensuring weld integrity and maintaining the desired mechanical properties in the joint.
8. Fordeler og begrensninger av 15-5 Rustfritt stål
Fordeler
- Høy styrke-til-vekt-forhold:
15-5 PH stainless steel offers excellent tensile and yield strength while maintaining relatively low density, making it ideal for weight-sensitive applications such as aerospace and high-performance engineering. - Excellent Toughness and Mechanical Stability:
The alloy demonstrates outstanding toughness, including across thick cross-sections and transverse directions, reducing the risk of brittle failure in critical components. - God korrosjonsmotstand:
It resists atmospheric, Marine, and mild chemical environments better than conventional martensitic stainless steels (F.eks., 410/420), enhancing durability in many industrial and marine settings. - Heat Treatability for Tailored Performance:
Its precipitation-hardening response allows engineers to customize mechanical properties (styrke, seighet, hardhet) through controlled aging cycles. - Good Machinability in Hardened Conditions:
Compared to many other stainless steels, 15-5 maintains relatively good machinability after aging, facilitating efficient manufacturing of precision parts.
Begrensninger
- Susceptibility to Chloride and Acidic Environments:
Despite improved corrosion resistance over some martensitic grades,
15-5 is not recommended for prolonged exposure to highly chloride-rich or strongly acidic environments; alternatives such as 316L or duplex stainless steels are preferred. - Requirement for Precise Heat Treatment:
Achieving optimal mechanical and corrosion properties depends on strict control of solution annealing and aging parameters, adding complexity to manufacturing and quality assurance. - Higher Cost Compared to Austenitic Stainless Steels:
Due to alloying elements and specialized processing, 15-5 typically costs more than common grades like 304 eller 316, potentially limiting its use to performance-critical applications. - Limited Cold-Forming Flexibility:
The alloy is less ductile and more prone to work hardening than austenitic stainless steels, restricting its formability and necessitating intermediate annealing during cold working.
9. Applikasjoner
15-5 stainless steel’s unique combination of high strength, seighet, Korrosjonsmotstand, and heat-treatability makes it a preferred material across a broad spectrum of demanding industries.
Luftfart
- Strukturelle komponenter: Used in airframe parts, parentes, and supports where the strength-to-weight ratio is critical.
- Shafts and Fasteners: Ideal for landing gear, aktuatorer, and high-strength fasteners due to their toughness and dimensional stability.
- Turbine and Engine Parts: Suitable for components requiring good fatigue resistance and thermal stability.
Medisinsk
- Orthopedic Instruments: Surgical tools and implants benefit from 15-5’s biocompatibility, Korrosjonsmotstand, og mekanisk pålitelighet.
- Surgical Tools: Scalpel handles, Klemmer, and other precision instruments use 15-5 stainless steel for durability and ease of sterilization.
Industriell
- Gear Parts and Valve Stems: High-strength gears, sjakter, and valve components in chemical and petrochemical plants.
- Pump Shafts and Fittings: Resistant to wear and corrosion in moderately aggressive environments.
- High-Strength Fittings: Used where weight savings and mechanical performance are essential.
Tilsetningsstoffproduksjon
- Metal Powder for 3D Printing: 15-5 PH stainless steel powder is increasingly used in Selektiv lasersmelting (Slm) og Direkte metalllaser sintring (DMLS) processes to produce complex, high-performance components with excellent mechanical properties.
10. Comparison with Similar Stainless Steels
15 5 PH stainless steel is part of the family of martensitic precipitation-hardening (Ph) rustfrie stål, and it shares many characteristics with alloys such as 17-4 Ph, 13-8 Mo, og 17-7 Ph.
Understanding its differences and advantages compared to these steels helps in selecting the most suitable material for specific applications.
| Eiendom / Legering | 15-5 Rustfritt stål | 17-4 Ph Rustfritt stål | 13-8 Mo Stainless Steel | 17-7 PH rustfritt stål |
| USAs betegnelse | S15500 | S17400 | S13800 | S17700 |
| Sammensetningshøydepunkter | ~15% Cr, 5% I, Cu, Nb | ~ 17% cr, 4% I, Cu, Nb | ~13% Cr, 8% I, Mo, Cu | ~ 17% cr, 7% I, Cu, Nb |
| Varmebehandling | Løsning andeal + aldring (H900–H1150M) | Løsning andeal + aldring (H900–H1150M) | Løsning andeal + aldring | Løsning andeal + aldring |
| Mekanisk styrke | Høy, up to ~1310 MPa tensile (H900) | Veldig høyt, up to ~1380 MPa tensile (H900) | Høyere styrke, God seighet | Moderat styrke, Utmerket duktilitet |
| Seighet | Superior toughness and transverse properties | Good toughness but lower than 15-5 | Høy seighet, improved over 17-4 Ph | Excellent toughness and formability |
| Korrosjonsmotstand | Better than 17-4 Ph, good marine resistance | God generell korrosjonsmotstand | God korrosjonsmotstand | Moderat korrosjonsmotstand |
| Maskinbarhet | God, especially in annealed and overaged states | God, widely used in machining | Moderat maskinbarhet | God maskinbarhet |
| Applikasjoner | Aerospace strukturelle deler, medisinsk utstyr | Luftfart, industriell, general-purpose PH | High-strength aerospace and chemical parts | Aerospace springs, presisjonsdeler |
| Koste | Moderat til høy | Moderat | Higher due to Mo content | Moderat |
Application Scope:
Mens 17-4 PH stainless steel is often the go-to for general-purpose applications due to its cost-effectiveness and wide availability, 15-5 PH stainless steel is preferred where higher toughness and dimensional stability are required.
13-8 Mo stainless steel offers higher strength but at increased cost, mens 17-7 PH stainless steel is valued for excellent ductility and spring properties.
11. Forms and Specifications of 15-5 Rustfritt stål
Available Forms
- Bar, rod, stripe, tallerken
- Forgings and extrusions
- Powder for AM (Tilsetningsstoffproduksjon)
Standarder og spesifikasjoner
- ASTM A564/A564M – Bars and shapes
- Ams 5659 – Aerospace components
- ASTM F899 – Surgical applications
- ISO 16061, I 10088-3 – International equivalents
12. Konklusjon
15-5 rustfritt stål stands out as a premium engineering alloy that blends høy styrke, Korrosjonsmotstand, og Dimensjonell stabilitet with excellent maskinbarhet.
Its widespread use in aerospace, medisinsk, and industrial sectors underscores its value where performance cannot be compromised.
With the increasing adoption of Tilsetningsstoffproduksjon, 15-5 PH also opens new frontiers in design flexibility and lightweighting without sacrificing strength.
While it demands precise processing and heat treatment, its benefits in critical applications continue to make it a material of choice for demanding engineering environments.
LangHe: Presisjon rustfritt stålstøping & Fabrikasjonstjenester
LangHe er en pålitelig leverandør av høykvalitets rustfritt stål og presisjon metall fabrikasjonstjenester, betjener næringer der ytelse, varighet, og korrosjonsmotstand er kritisk.
Med avanserte produksjonsevner og en forpliktelse til teknisk dyktighet, LangHe leverer pålitelig, Tilpassede rustfrie stålløsninger for å oppfylle de mest krevende applikasjonskravene.
Våre evner i rustfritt stål inkluderer:
- Investering Casting & Mistet voksstøping
Støping med høy presisjon for komplekse geometrier, sikre stramme toleranser og overlegen overflatebehandling. - Sandstøping & Skallstøping
Ideell for større komponenter og kostnadseffektiv produksjon, Spesielt for industrielle og strukturelle deler. - CNC maskinering & Etterbehandling
Komplette maskineringstjenester inkludert sving, fresing, boring, polere, og overflatebehandlinger.
Enten du trenger komponenter med høy presisjon, komplekse rustfrie samlinger, eller tilpassede konstruerte deler, LangHe er din pålitelige partner innen produksjon av rustfritt stål.
Kontakt oss i dag å lære hvordan LangHe kan levere rustfrie stålløsninger med ytelsen, Pålitelighet, og presisjon din bransje krever.
Vanlige spørsmål
Er 15-5 steel magnetic?
Ja, 15-5 ph stainless steel is magnetic in all conditions due to its martensitic crystal structure.
Kan 15-5 rustfritt stål sveises?
Ja, Men sveising krever forvarming (typically 150–200°C), proper filler metals, and often post-weld heat treatment to avoid cracking and maintain mechanical properties.
Er 15-5 stainless steel suitable for additive manufacturing?
Ja, 15-5 stainless steel powder is widely used in selective laser melting (Slm) and direct metal laser sintering (DMLS) to produce complex, Høytytende komponenter.
