1.4878 Nerūsējošais tērauds: Īpašības, Sastāvs, Lietojumprogrammas

In the world of high‑temperature stainless steels, 1.4878—known by its material number EN 1.4878 and corresponding to UNS S32109 (ASTM 321H)- is a titanium-stabilized chromium-nickel austenitic stainless steel that combines excellent oxidation resistance with superior resistance to intergranular corrosion after welding or prolonged exposure to elevated temperatures.

By incorporating titanium, the alloy minimizes chromium carbide precipitation, allowing it to maintain corrosion resistance and structural integrity where conventional unstabilized grades may fail.

Because of these characteristics, 1.4878 stainless steel is widely used in heat exchangers, krāsns sastāvdaļas, izplūdes sistēmas, petrochemical equipment, spiediena tvertnes, power generation plants, and industrial heat treatment equipment.

It is available in numerous product forms—including plates, loksnes, pīpes, caurules, stieņi, BIGNIEKUMI, and precision investment castings—making it suitable for both fabricated structures and complex engineered components.

1. Kas ir 1.4878 Nerūsējošais tērauds?

1.4878 nerūsējošais tērauds (Iekšā 1.4878 / X12CrNiTi18-9) ir a titāna stabilizēta austenīta nerūsējošais tērauds developed for applications involving prolonged exposure to elevated temperatures and cyclic thermal loading.

It belongs to the family of chromium-nickel heat-resistant stainless steels and offers an excellent balance of oxidation resistance, metināmība, izturība, and resistance to intergranular corrosion.

Unlike standard austenitic grades, which may become sensitized after welding or long-term service between approximately 450° C un 850 ° C, 1.4878 incorporates titanium as a stabilizing element.

Titanium preferentially reacts with carbon to form stable titanium carbides instead of chromium carbides.

Rezultātā, chromium remains dissolved in the steel matrix, preserving the protective chromium oxide film that gives stainless steel its corrosion resistance.

Why Is 1.4878 Stabilized with Titanium?

The defining feature of 1.4878 stainless steel is its titāna stabilizācija, which significantly enhances its performance under elevated temperatures and after welding.

When conventional austenitic stainless steels are exposed to temperatures within the sensitization range (parasti 450–850 ° C), carbon atoms diffuse through the microstructure and combine with chromium to form chromium carbides along grain boundaries.

Šis process, pazīstams kā sensibilizācija, creates chromium-depleted zones adjacent to the grain boundaries.

Because chromium is essential for forming the passive oxide film, these depleted regions become highly susceptible to starpgranulārā korozija.

Iekšā 1.4878 nerūsējošais tērauds, titanium has a much stronger affinity for carbon than chromium.

During solidification and subsequent heat exposure, titanium reacts first to form titanium carbides (Tik).

These stable carbides effectively “lock up” the carbon, preventing chromium carbide precipitation and preserving the chromium content within the surrounding matrix.

This stabilization mechanism provides several important engineering advantages:

• Improved resistance to intergranular corrosion after welding
• Greater microstructural stability during prolonged high-temperature service
• Enhanced creep performance under sustained thermal loading
• Reduced need for post-weld solution annealing
• Longer service life in cyclic heating environments

Rezultātā, 1.4878 is especially suitable for large welded fabrications that cannot easily undergo post-weld heat treatment, such as pressure vessels, furnace assemblies, and process piping.

Common Standards for 1.4878 Nerūsējošais tērauds

Distinction from 1.4541 (Standarta 321)

The most frequent point of confusion is the relationship between 1.4878 (321H) un 1.4541 (standarta 321 / X6crniti18-10).

Abi ir titāna stabilizēti 18-10 Austenīta nerūsējošā tēraudi, and they share the same corrosion resistance and general metallurgical characteristics.

The defining difference lies in carbon content specification:

• 1.4541 (321): maximum carbon 0.08%, general-purpose stabilized grade
• 1.4878 (321H): controlled carbon range of 0.04–0.10%, with intentional minimum carbon content

The “H” suffix in 321H stands for “high carbon”.

The elevated minimum carbon content is deliberately specified to improve high-temperature tensile strength, creep resistance and stress-rupture life, veidošana 1.4878 the heat-resistant optimized variant of the 321 ģimene.

Many mills dual-certify material to both standards when composition falls within the overlapping range.

2. Ķīmiskais sastāvs 1.4878 Nerūsējošais tērauds

Izcilā izrāde 1.4878 nerūsējošais tērauds (X12CrNiTi18-9) is the result of a carefully balanced chemical composition.

Each alloying element performs a specific metallurgical function, contributing to corrosion resistance, high-temperature oxidation resistance, metināmība, mehāniskā izturība, and microstructural stability.

The chemical composition specified by EN standards is shown below.

Atzīmēt: Actual chemical composition may vary slightly depending on the applicable EN, No, ASTM, or customer specification.

3. Fiziskās īpašības 1.4878 Nerūsējošais tērauds

Fiziskās īpašības 1.4878 stainless steel determine how the material responds to heat transfer, termiskā izplešanās, elektriskā vadītspēja, and magnetic fields during service.

These properties are particularly important when designing components for furnaces, siltummaiņi, Izplūdes kolektori, and pressure equipment operating under continuous thermal cycling.

Values are typical reference data and may vary slightly with product form, apstrādes ceļš, and applicable standards.

4. Mehāniskās īpašības 1.4878 Nerūsējošais tērauds

Mehāniskās īpašības 1.4878 stainless steel reflect its primary role as a high-temperature structural material.

While its room-temperature strength is similar to that of conventional austenitic stainless steels, its real advantage lies in maintaining mechanical integrity during prolonged service at elevated temperatures.

Values are representative of solution-annealed material and may vary depending on product form and manufacturing process.

5. Heat Resistance and High-Temperature Performance

The primary advantage of 1.4878 nerūsējošais tērauds lies in its outstanding performance under elevated-temperature service conditions.

Unlike conventional austenitic grades such as 304, which are mainly designed for corrosion resistance at ambient temperatures, 1.4878 is engineered to maintain its structural integrity, izturība pret oksidāciju, and corrosion performance during prolonged exposure to heat.

Recommended Service Temperature

The following table summarizes the typical operating temperature ranges for 1.4878 nerūsējošais tērauds.

Actual service limits depend on component geometry, applied stress, furnace atmosphere, thermal cycling frequency, and design life.

Excellent Oxidation Resistance

Paaugstinātā temperatūrā, chromium rapidly reacts with oxygen to form a dense chromium oxide (Cr₂o₃) layer that protects the underlying metal from further oxidation.

This passive oxide film continuously regenerates if damaged, providing long-term resistance against scaling in air and many combustion environments.

Because of its stable chromium content, 1.4878 demonstrates excellent resistance to:

• High-temperature oxidation
• Surface scaling
• Decarburization
• Hot gas corrosion in mildly oxidizing atmospheres

These characteristics make it suitable for furnace components, industrial heaters, thermal processing equipment, un izplūdes sistēmas.

Superior Resistance to Thermal Cycling

Many industrial components experience repeated heating and cooling rather than constant temperatures.

These thermal cycles generate expansion and contraction stresses that may eventually lead to distortion, fatigue cracking, or weld failure.

The fully austenitic microstructure of 1.4878 provides excellent resistance to thermal fatigue because it combines:

• Augsta elastība
• Stable grain structure
• Laba izturība
• Low susceptibility to brittle fracture

Titanium stabilization further minimizes microstructural degradation during repeated thermal exposure, extending service life in cyclic operating environments.

Creep and Stress-Rupture Resistance

For components operating continuously at elevated temperatures, creep resistance is often more important than room-temperature strength.

Creep is the slow, permanent deformation of a material under sustained load at high temperature.

In industrial furnaces, katli, naftas ķīmijas reaktori, un siltummaiņi, creep deformation can gradually alter component dimensions and eventually lead to failure.

Compared with standard 304 nerūsējošais tērauds, 1.4878 piedāvājums:

• Improved creep strength
• Better stress-rupture resistance
• Enhanced grain boundary stability
• Reduced deformation during prolonged service

These improvements are primarily attributed to titanium stabilization, which suppresses chromium carbide precipitation and helps preserve grain boundary strength.

Resistance to Sensitization During High-Temperature Service

One of the most significant advantages of 1.4878 is its ability to resist sensitization after prolonged exposure to temperatures between 450° C un 850 ° C.

Standarta 304 stainless steel may suffer chromium depletion near grain boundaries after welding or extended heating, increasing the risk of intergranular corrosion.

Turpretī, titanium preferentially reacts with carbon to form titanium carbides, preventing chromium carbide precipitation and allowing chromium to remain available for maintaining the protective passive film.

Rezultātā, 1.4878 is particularly suitable for:

• Welded furnace structures
• Petrochemical piping
• Heat treatment fixtures
• Power plant components
• High-temperature pressure vessels

6. Izturība pret koroziju

Vispārēja korozija

At ambient and moderately elevated temperatures, 1.4878 exhibits good general corrosion resistance in atmospheric environments, saldūdens, steam and most organic and inorganic chemicals.

Its performance is broadly comparable to 304 stainless steel in non-sensitized conditions.

Intergranular Corrosion Resistance

This is where 1.4878 distinguishes itself from unstabilized grades.

In the as-welded or as-heated condition, unstabilized steels such as 304 suffer chromium carbide precipitation at grain boundaries (sensibilizācija), leading to intergranular corrosion.

Iekšā 1.4878, titanium sequesters carbon, preventing significant chromium depletion and maintaining full intergranular corrosion resistance even after exposure to the 450–850°C sensitization range.

This property is particularly valuable for large welded structures and furnace components that cannot be solution-annealed after fabrication.

Lokalizēta korozija

Pitting and crevice corrosion resistance is moderate, roughly equivalent to 304 nerūsējošais tērauds.

The grade is not intended for severe chloride environments; 316L or higher-alloyed materials are preferred for such service.

1.4878 stainless steel is not suitable for seawater or high-chloride process streams.

Stresa korozijas plaisāšana

Tāpat kā citi austenītiski nerūsējoši tēraudi, 1.4878 stainless steel is susceptible to chloride-induced stress corrosion cracking at elevated temperatures.

For applications combining tensile stress with hot chloride environments, alternative materials should be considered.

7. Fabrication and Welding Characteristics

Despite being designed for elevated-temperature applications, 1.4878 nerūsējošais tērauds offers excellent manufacturability.

Its fully austenitic structure provides outstanding ductility and toughness, allowing the material to be formed into complex geometries while maintaining dimensional accuracy and structural integrity.

Veidošanās un izgatavošana

1.4878 possesses excellent cold-forming characteristics and can be processed using conventional sheet metal fabrication techniques.

Typical forming operations include:

• Dziļa zīmēšana
• Veidošana
• Saliekšana
• Stretch forming
• Hydroforming
• Press forming
• Vērpšana

Because the alloy work-hardens rapidly, severe deformation may require intermediate annealing to restore ductility before further processing.

Hot forming is typically performed within the temperature range of 1050–1200 ° C, followed by rapid cooling to preserve the fully austenitic microstructure.

Apstrādes īpašības

Compared with carbon steels and free-machining stainless steels, 1.4878 stainless steel is considered moderately difficult to machine.

Its high toughness, lieliska elastība, and strong tendency to work harden increase cutting forces and generate considerable heat at the tool-workpiece interface.

If machining parameters are not properly controlled, the work-hardened surface can accelerate tool wear and reduce dimensional accuracy.

Laikā apstrāde, the material tends to generate:

• High cutting forces
• Elevated cutting temperatures
• Continuous chips
• Accelerated tool wear

Efficient machining therefore requires:

• Sharp carbide or ceramic cutting tools
• Positive rake geometries
• Adequate cutting fluid
• Mērens griešanas ātrums
• Stable machine rigidity

Using interrupted cutting conditions or worn tooling should be avoided because work-hardened surfaces can rapidly reduce machining efficiency.

Precizitātes liešana

Kaut gan 1.4878 stainless steel is primarily supplied as wrought products in the form of plates, stieņi, pīpes, and forgings, it is also suitable for manufacturing complex components by investīciju liešana (zaudēta vaska liešana).

Precision casting offers significant advantages for geometrically intricate parts that would otherwise require extensive machining, reducing both material waste and overall production costs.

Investment casting is particularly suitable for producing:

• Furnace fixtures
• Burner components
• Heat-resistant brackets
• Exhaust system parts
• Complex industrial hardware

Proper control of melting practice, pelējuma dizains, and solidification conditions is essential to minimize segregation, saraušanās defekti, and hot cracking while ensuring a uniform austenitic microstructure.

Following casting, solution annealing is typically performed to optimize corrosion resistance and mechanical properties.

Metināšanas īpašības

One of the greatest advantages of 1.4878 is its outstanding weldability.

Because titanium stabilizes carbon, the alloy exhibits significantly lower susceptibility to sensitization than unstabilized 304 nerūsējošais tērauds.

It is compatible with virtually all common fusion welding processes, ieskaitot:

• Gtaw (TIG)
• Ieeja (Es)
• Smirdēt
• Zāģis
• Plasma arc welding
• Laser welding

Proper filler metal selection is important to ensure matching high-temperature performance and corrosion resistance.

8. Termiskā apstrāde 1.4878 Nerūsējošais tērauds

Unlike martensitic or precipitation-hardening stainless steels, 1.4878 cannot be strengthened through conventional heat treatment.

Its mechanical properties are primarily controlled by solid-solution strengthening, aukstā darbība, and titanium stabilization rather than phase transformation.

The principal objectives of heat treatment are therefore to restore corrosion resistance, dissolve undesirable precipitates, relieve fabrication stresses, and maintain a stable austenitic microstructure.

9. Virsmas apdare

The surface finish of 1.4878 stainless steel significantly influences not only its appearance but also its corrosion resistance, tīrība, friction characteristics, un kalpošanas laiks.

Selecting the appropriate finish depends on the operating environment, fabrication method, and functional requirements of the final component.

10. Tipiski pielietojumi 1.4878 Nerūsējošais tērauds

The combination of excellent corrosion resistance, high-temperature oxidation resistance, outstanding weldability, and long-term structural stability makes 1.4878 stainless steel one of the preferred materials for demanding industrial environments.

Naftas ķīmijas un ķīmiskā apstrāde

Chemical plants frequently operate under aggressive conditions involving elevated temperatures, pressurized fluids, un korozīvi plašsaziņas līdzekļi.

1.4878 stainless steel provides excellent resistance to oxidation, organiskās skābes, and many industrial chemicals while maintaining structural integrity during thermal cycling.

Typical components include:

• Siltummaiņi
• Reaktora trauki
• Process piping
• Expansion joints
• Spiediena tvertnes
• Destilācijas kolonnas
• Flanges and fittings

Industrial Furnaces and Heat Treatment Equipment

One of the most important application areas for 1.4878 is high-temperature furnace construction.

The alloy withstands continuous exposure to elevated temperatures while resisting oxidation, termiskais nogurums, and scaling.

Common furnace components include:

• Furnace rollers
• Starojošās caurules
• Furnace baskets
• Heat-treatment trays
• Annealing fixtures
• Burner assemblies
• Retorts
• Support grids

Enerģijas ražošana

Steam boilers, waste heat recovery systems, and thermal power plants expose structural components to high temperatures and cyclic thermal stresses.

Titanium stabilization improves long-term reliability by preventing grain-boundary sensitization during extended operation.

Tipiskas lietojumprogrammas ietver:

• Katlu caurules
• Superheater supports
• Exhaust ducting
• Flue gas systems
• Steam piping accessories

Automotive and Exhaust Systems

The alloy performs well under repeated heating and cooling cycles encountered in vehicle exhaust systems.

Its oxidation resistance and weldability make it suitable for manufacturing durable exhaust components.

Piemēri ietver:

• Izplūdes kolektori
• Turbocharger piping
• Exhaust bellows
• Catalyst housings
• Siltuma vairogi

Pārtikas pārstrādes aprīkojums

Although not as widely used as 304L or 316L in food production, 1.4878 becomes advantageous where processing equipment experiences frequent high-temperature cleaning or sterilization.

Typical equipment includes:

• Sterilization chambers
• High-temperature conveyors
• Industrial ovens
• Heat-resistant processing equipment

Precision Castings and Fabricated Components

The alloy is also widely used in precision investment castings and fabricated assemblies that combine corrosion resistance with elevated-temperature performance.

Representative products include:

• Vārstu ķermeņi
• Sūkņa komponenti
• Furnace accessories
• Turbine hardware
• Rūpniecības iekavas
• High-temperature fasteners
• Mechanical supports

11. Priekšrocības un ierobežojumi 1.4878 Nerūsējošais tērauds

Priekšrocības

Excellent Resistance to Intergranular Corrosion

Titanium stabilization effectively binds carbon into stable titanium carbides, preventing chromium carbide precipitation during welding or prolonged service at elevated temperatures.

This significantly improves long-term corrosion resistance in the critical temperature range where unstabilized austenitic stainless steels may become sensitized.

Izcils augstas temperatūras sniegums

1.4878 maintains excellent oxidation resistance and mechanical stability during continuous operation at temperatures approaching 800–850 ° C, making it highly suitable for furnace equipment, izplūdes sistēmas, and thermal processing machinery.

Lieliska metināmība

The alloy can be welded using virtually all conventional fusion welding methods with minimal risk of weld decay.

Large fabricated structures can often be placed into service without post-weld solution annealing, simplifying manufacturing while reducing production costs.

Good General Corrosion Resistance

In many industrial environments, 1.4878 provides corrosion resistance comparable to Type 304 nerūsējošais tērauds, including excellent resistance to atmospheric corrosion, saldūdens, tvaika, and numerous organic chemicals.

High Toughness Across a Wide Temperature Range

The fully austenitic microstructure provides excellent impact toughness and ductility at both ambient and moderately elevated temperatures, allowing reliable performance under dynamic loading and thermal cycling.

Excellent Fabrication Performance

The alloy supports a wide range of manufacturing processes, ieskaitot:

• Auksta formēšana
• Karsta formēšana
• Precision investment casting
• CNC apstrāde
• Dziļa zīmēšana
• Ritošs
• Metināšana

This versatility allows engineers to produce complex components with high dimensional accuracy.

Ilgs kalpošanas laiks

The combination of oxidation resistance, izturība pret koroziju, weld stability, and thermal durability contributes to extended equipment life, reducing maintenance frequency and lifecycle costs in demanding industrial applications.

Ierobežojumi

Mērena apstrādājamība

Like most austenitic stainless steels, 1.4878 exhibits significant work hardening during machining.

Cutting operations require rigid equipment, asi instrumenti, effective cooling, and optimized machining parameters to achieve satisfactory productivity and tool life.

Limited Resistance to Chloride-Induced Pitting

Although the alloy performs well in many industrial environments, its molybdenum-free composition makes it less resistant to chloride-induced pitting and crevice corrosion than grades such as 316L.

It is therefore not the preferred choice for marine environments or highly saline process media.

Higher Material Cost Than Standard Carbon Steels

The presence of nickel, hroms, and titanium increases the material cost compared with carbon steels and some ferritic stainless steels.

Tomēr, the higher initial investment is often justified by improved durability and lower maintenance requirements.

Not Intended for Extremely High Temperatures

Kamēr 1.4878 performs exceptionally well at elevated temperatures, applications involving continuous exposure above approximately 900° C generally require more heat-resistant grades such as 310S (1.4845) or nickel-based superalloys.

Termiskā izplešanās

Tāpat kā citi austenītiski nerūsējoši tēraudi, the alloy has a relatively high coefficient of thermal expansion.

Designers should account for thermal movement in large welded structures, cauruļvadu sistēmas, and furnace assemblies by incorporating appropriate expansion allowances.

12. 1.4878 vs Other Stainless Steel Grades

Selecting the appropriate stainless steel requires balancing corrosion resistance, temperature capability, izgatavošanas prasības, un izmaksas.

Kaut gan 1.4878 shares many characteristics with other austenitic stainless steels, its titanium stabilization makes it particularly suitable for welded structures and long-term service at elevated temperatures.

1.4878 vs 1.4541 (321) Nerūsējošais tērauds

Both grades are titanium-stabilized chromium-nickel stainless steels and provide excellent resistance to intergranular corrosion after welding.

Tomēr, 1.4878 contains a slightly higher carbon level, which contributes to improved creep strength and elevated-temperature mechanical performance.

For components operating continuously under thermal stress—such as furnace structures, spiediena tvertnes, and petrochemical equipment—1.4878 is generally preferred.

Typical selection guidance:

• Izvēlēties 1.4878 for prolonged high-temperature service and pressure-bearing components.
• Izvēlēties 1.4541 (321) for general high-temperature fabrication, aircraft exhaust systems, and standard welded structures.

1.4878 vs 1.4404 (316Lukturis) Nerūsējošais tērauds

These two grades are designed for different service environments.

1.4404(316Lukturis)nerūsējošais tērauds derives its superior corrosion resistance from approximately 2–2.5% molybdenum, making it highly resistant to chloride-induced pitting and crevice corrosion.

Līdz ar to, it is the preferred choice for marine environments, farmaceitiskā apstrāde, and aggressive chemical applications.

1.4878 nerūsējošais tērauds, turpretī, is optimized for elevated-temperature performance rather than chloride resistance.

Its titanium stabilization prevents sensitization during prolonged heating, allowing it to retain mechanical integrity where 316L would gradually lose strength.

General recommendation:

• Izvēlieties 316Lukturis for seawater exposure, coastal installations, and chloride-containing process media.
• Izvēlieties 1.4878 for temperatures above approximately 500°C where thermal stability becomes more important than chloride resistance.

1.4878 vs 1.4845 (310S) Nerūsējošais tērauds

Both grades perform well at elevated temperatures, but they are intended for different operating ranges.

Ar aptuveni 25% hroms un 20% niķelis, 310S exhibits exceptional oxidation resistance and can withstand continuous temperatures approaching 1100° C.

It is widely used in furnace linings, radiant tubes, degļi, and thermal processing equipment exposed to extremely high temperatures.

Kaut gan 1.4878 cannot match the maximum operating temperature of 310S, it offers better weld stability, lower material cost, and sufficient heat resistance for many industrial applications below approximately 850° C.

Rezultātā:

• Izvēlēties 310S for ultra-high-temperature furnace environments.
• Izvēlēties 1.4878 for high-temperature structural fabrications requiring excellent weldability, šļūdes pretestība, un ilgtermiņa uzticamība.

13. Why Choose LangHe for 1.4878 Nerūsējošā tērauda izstrādājumi?

Manufacturing components from 1.4878 stainless steel requires more than simply selecting the correct alloy.

Achieving reliable performance in high-temperature and corrosive environments depends on precise process control, materiāla izsekojamība, advanced manufacturing capabilities, un stingra kvalitātes nodrošināšana.

Pie LangHe, we combine metallurgical expertise with modern production technologies to deliver precision-engineered 1.4878 stainless steel components that meet the demanding requirements of industrial customers worldwide.

14. Secinājums

1.4878 (X8CrNiTi18-10 / 321H) occupies a well-defined and important niche in the heat-resistant stainless steel spectrum.

By combining titanium stabilization with controlled higher carbon content, it delivers two properties that are difficult to obtain simultaneously in austenitic stainless steels:

immunity to intergranular corrosion after welding, and significantly improved creep and stress-rupture performance at elevated temperatures.

It is not the highest-temperature grade, nor the most corrosion-resistant grade, but it offers an unrivaled balance of heat resistance, metināmība, fabricability and cost for components operating in the 500–900°C range.

For boiler tubes, furnace hardware, petrochemical process equipment and heat treatment fixtures, it remains the benchmark standard material against which alternatives are measured.

As global industry continues to push process temperatures higher in pursuit of energy efficiency and emissions reduction,

1.4878 stainless steel will remain a foundational material for medium-temperature load-bearing service, valued for its proven reliability, predictable performance and mature manufacturing base.

FAQ

Kāda ir atšķirība starp 1.4878 un 1.4541 nerūsējošais tērauds?

Abi ir titāna stabilizēti 18-10 Austenīta nerūsējošā tēraudi. 1.4541 (standarta 321) has a maximum carbon of 0.08%, kamēr 1.4878 (321H) has a controlled carbon range of 0.04–0.10%.

The higher minimum carbon in 1.4878 improves high-temperature creep and stress-rupture strength, making it the preferred choice for load-bearing high-temperature service.

What is the maximum operating temperature for 1.4878 nerūsējošais tērauds?

Up to 850°C for continuous service and 900°C for intermittent service. For temperatures above 900°C, 310S (1.4845) ir ieteicams.

Ir 1.4878 nerūsējošā tērauda magnētiskais?

Ne. 1.4878 is an austenitic stainless steel and is paramagnetic (nemagnētisks) rūdītā stāvoklī. Cold working may induce some ferromagnetism.

Bēgt 1.4878 stainless steel be welded without filler?

For small sections, autogenous welding is possible, but matching filler (ER321) is recommended to maintain stabilisation and corrosion resistance.

Does 1.4878 stainless steel require post‑weld heat treatment?

Ne. Titanium stabilisation prevents sensitisation, so post‑weld heat treatment is not required.

Kāda ir atšķirība starp 1.4878 un 1.4404 (316Lukturis) nerūsējošais tērauds?

1.4878 has titanium stabilisation and higher carbon for high‑temperature creep strength, but no molybdenum.

1.4404 (316Lukturis) stainless steel has molybdenum for superior chloride corrosion resistance but is limited to lower temperatures (≤400°C) for long‑term service.