Product Description
Seamless Tube Size: Outside Diameter: 6.0mm-127mm (1/8"-5"), Wall Thickness: 0.5mm-12.7mm, Length: 6m, 12m or as required. Custom lengths up to 18m available.
Standard & Grade of Seamless Tube: ASTM A213 Grade TP321 (UNS S32100, Werkstoff 1.4541); Also available TP321H (UNS S32109, Werkstoff 1.4878) for higher temperature service
Usage of Seamless Tube: Boiler tubes, superheater tubes, heat exchanger tubes, condenser tubes, high temperature steam lines, power generation, petrochemical processing, refinery equipment, chemical plants, high temperature headers, furnace tubes, thermal oxidizers, waste heat recovery units, high temperature corrosive service
Womic Steel offering high quality & competitive prices of ASTM A213 TP321 stainless steel seamless tubes, boiler tubes, heat exchanger tubes, pipe fittings. Mill certificate, hydro test, UT/ET inspection, flaring/flattening test, beveled end available. Fast delivery and best service.
Womic Steel: Manufacturing Capabilities & Company Strength
Womic Steel Group is a premier manufacturer and global exporter with over 20 years of expertise in producing carbon, alloy, and stainless steel tubular products. Our state-of-the-art seamless tube production facility specializes in stainless steel seamless pipes and tubes for high temperature and corrosive service applications.
Production Size Range for ASTM A213 TP321 Seamless Tube: Outside diameter from 6.0mm to 127mm (1/8 inch to 5 inch) with wall thickness from 0.5mm to 12.7mm. Single random lengths of 6m, double random lengths of 12m, or custom lengths up to 18m as required. Cold drawn and cold rolled processes available for precision dimensional tolerances and superior surface finish.
Quality Certifications & Regulatory Compliance:
ISO 9001:2015 Certified: Quality management system ensuring consistent product quality across all operations.
ASTM A213 Compliance: Full compliance with ASTM A213/A213M Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes .
PED 2014/68/EU (CE Marking): Compliance with European Pressure Equipment Directive for boiler and pressure applications. CE marking available upon request.
ASME Boiler and Pressure Vessel Code: Section II materials certification available for ASME Code applications.
EN 10204 3.2 Certification: Inspection Certificate 3.2 validated by TÜV, LR, BV, or SGS for critical applications requiring full material traceability.
NACE MR0175 / ISO 15156: Certification available for sour service applications requiring H₂S resistance.
Third-Party Inspection (TPI) Approvals: Products and processes approved by SGS, BV, ABS, LR, DNV, GL, and TÜV.
Global Recognition: Womic Steel is a trusted supplier to boiler manufacturers, heat exchanger fabricators, power plants, petrochemical facilities, and refineries, serving over 80 countries worldwide.
ASTM A213 TP321 Stainless Steel Seamless Tube: Material Composition & Performance Characteristics
ASTM A213 TP321 is a titanium-stabilized austenitic stainless steel seamless tube specifically designed for high temperature service. The "TP" denotes tubular product, "321" indicates the grade designation. The titanium addition (typically 5×C minimum, 0.70% maximum) stabilizes the material against chromium carbide precipitation, providing excellent resistance to intergranular corrosion after exposure to temperatures in the range of 425-850°C .
Compared to unstabilized grades like TP304 and TP304L, TP321 offers superior resistance to sensitization and intergranular corrosion when subjected to welding or prolonged service in the carbide precipitation range. TP321 is also available in a high carbon version (TP321H, UNS S32109) for applications requiring improved high temperature strength and creep resistance .
ASTM A213 TP321 Stainless Steel Seamless Tube Chemical Composition (Ladle Analysis, % by mass):
| Element | TP321 Requirement | TP321H Requirement |
| Carbon (C) | ≤ 0.08 | 0.04 - 0.10 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.030 |
| Silicon (Si) | ≤ 0.75 | ≤ 0.75 |
| Chromium (Cr) | 17.0 - 19.0 | 17.0 - 19.0 |
| Nickel (Ni) | 9.0 - 12.0 | 9.0 - 12.0 |
| Titanium (Ti) | ≥ 5×C, ≤ 0.70 | ≥ 4×C, ≤ 0.70 |
| Nitrogen (N) | ≤ 0.10 | ≤ 0.10 |
Note: The titanium addition stabilizes the material by forming titanium carbides (TiC) rather than chromium carbides at grain boundaries. This prevents sensitization and maintains corrosion resistance even after welding or high temperature exposure .
ASTM A213 TP321 Stainless Steel Seamless Tube Mechanical Properties (Room Temperature):
| Property | TP321 Requirement | TP321H Requirement |
| Tensile Strength (min) | 515 MPa (75,000 psi) | 515 MPa (75,000 psi) |
| Yield Strength (min, 0.2% offset) | 205 MPa (30,000 psi) | 205 MPa (30,000 psi) |
| Elongation (min, 2" gauge) | 35% | 35% |
| Hardness (max) | 92 HRB / 210 HV | 92 HRB / 210 HV |
*Note: Mechanical properties are determined on specimens taken from tubes in the annealed condition. For seamless tubes with wall thickness greater than 3/8" (9.5mm), lower strength requirements may apply .*
ASTM A213 TP321 Stainless Steel Seamless Tube Physical Properties:
| Property | Value |
| Density | 8.0 g/cm³ (0.289 lb/in³) |
| Melting Point | 1400-1425°C (2550-2600°F) |
| Specific Heat (0-100°C) | 500 J/kg·K |
| Thermal Conductivity (100°C) | 16.3 W/m·K |
| Electrical Resistivity | 72 μΩ·cm |
| Modulus of Elasticity | 193 GPa (28.0 × 10⁶ psi) |
| Mean Coefficient of Thermal Expansion (0-315°C) | 17.2 μm/m·K |
ASTM A213 TP321 Stainless Steel Seamless Tube High Temperature Tensile Properties:
| Temperature (°C) | Yield Strength (min, MPa) | Tensile Strength (min, MPa) |
| 200 | 155 | 430 |
| 300 | 135 | 420 |
| 400 | 120 | 410 |
| 500 | 110 | 400 |
| 600 | 100 | 390 |
Note: TP321 maintains useful strength up to 816°C (1500°F) for ASME Code applications, significantly higher than TP304L (426°C limit) .
ASTM A213 TP321 Stainless Steel Seamless Tube Creep and Stress Rupture Properties:
| Temperature (°C) | Stress for 1% Creep in 100,000h (MPa) | Stress Rupture in 100,000h (MPa) |
| 600 | 70 | 95 |
| 650 | 40 | 60 |
| 700 | 25 | 38 |
| 760 | 12 | 20 |
Note: TP321 offers higher creep and stress rupture properties than TP304 and TP304L, making it the preferred choice for prolonged high temperature service .
Stabilization and Intergranular Corrosion Resistance:
The titanium addition in TP321 serves a critical function: titanium has a higher affinity for carbon than chromium does. When the material is heated in the carbide precipitation range (425-850°C), titanium preferentially forms titanium carbides (TiC) instead of allowing chromium carbides (Cr₂₃C₆) to form at grain boundaries. This prevents the depletion of chromium in the grain boundary regions, maintaining the material's corrosion resistance .
For applications involving welding or prolonged service in this temperature range, TP321 is superior to unstabilized grades like TP304 and TP304L. However, TP321 is somewhat less resistant to general corrosion in strongly oxidizing environments than TP347, which uses columbium/tantalum stabilization .
Grade Comparison:
| Grade | Stabilization | Carbon Content | High Temp Limit | Typical Application |
| TP304 | None (unstabilized) | ≤ 0.08 | 800°F (427°C) | General corrosive service |
| TP304L | None (low carbon) | ≤ 0.03 | 800°F (427°C) | Welded applications |
| TP321 | Titanium | ≤ 0.08 | 1500°F (816°C) | High temp, intergranular corrosion resistance |
| TP321H | Titanium | 0.04-0.10 | 1500°F (816°C) | High temp, improved creep strength |
| TP347 | Columbium/Tantalum | ≤ 0.08 | 1500°F (816°C) | High temp, stronger oxidizing environments |
ASTM A213 TP321 Stainless Steel Seamless Tube Dimensional Range & Standards Compliance
Womic Steel supplies ASTM A213 TP321 stainless steel seamless tubes across a wide dimensional spectrum, fully compliant with ASTM A213/A213M standard.
| Item | Specification |
| Standard | ASTM A213/A213M (Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes) |
| Grade | TP321 (UNS S32100, Werkstoff 1.4541) / TP321H (UNS S32109, Werkstoff 1.4878) |
| Manufacturing Process | Seamless - Cold Drawn / Cold Rolled / Cold Pilgered |
| Outside Diameter Range | 6.0mm – 127mm (1/8" – 5") |
| Wall Thickness Range | 0.5mm – 12.7mm (0.015" – 0.500") |
| Length | 6m (SR), 12m (DR), or custom lengths up to 18m (60ft) |
| Delivery Condition | Annealed and Pickled / Bright Annealed (BA) / Cold Drawn |
| End Finish | Plain End (PE) / Beveled End (BE) |
| Surface Finish | Annealed & Pickled / Bright Annealed / Polished / Mechanical Polished |
| Special Tests | Flaring Test / Flattening Test / Hydrostatic Test / Eddy Current Test / Ultrasonic Test |
| Tolerances | OD: ±0.1mm for precision tubes, ±0.5mm for standard / WT: ±10% / Length: +50mm -0mm |
Manufacturing Process – Stainless Steel Seamless Tube
Womic Steel produces ASTM A213 TP321 stainless steel seamless tubes using advanced cold drawing and cold rolling processes, ensuring precise dimensional tolerances and superior surface finish.
Production Workflow (Cold Drawn / Cold Rolled Seamless Tube Process):
Raw Material Inspection (Billet): Incoming stainless steel round billets (typically 50-200mm diameter) are verified for chemical composition per ASTM A213 TP321 requirements (17-19% Cr, 9-12% Ni, Ti ≥ 5×C). Each billet is assigned a unique heat number for full material traceability throughout production.
Billet Heating & Piercing: Billets are heated to forging temperature (1150-1250°C) in rotary hearth furnaces and pierced via cross-roll piercing mill (Mannesmann process) to form hollow tube shells (hollow blooms).
Extrusion or Rolling: The pierced hollow shells undergo further hot rolling or extrusion to reduce diameter and wall thickness. For TP321, careful temperature control prevents titanium carbide precipitation during hot working.
Annealing (Intermediate): After hot working, tubes are solution annealed at 1040-1120°C followed by rapid cooling (water quenching or air cooling) to dissolve carbides and restore corrosion resistance.
Pickling & Descaling: Scale formed during annealing is removed by pickling in acid baths (nitric-hydrofluoric acid mixture), revealing a clean, uniform surface.
Cold Drawing (Single or Multiple Passes): Tubes undergo single or multiple cold drawing passes through precision dies and over mandrels to achieve required OD, WT, and dimensional tolerances. Typical reduction per pass: 20-40%.
Cold Rolling (Pilgering - Optional): For greater wall thickness reduction or improved surface finish, tubes are processed through cold pilger mills. This process is particularly effective for thin-wall and precision tubes.
Intermediate Annealing: Between drawing or rolling passes, tubes undergo intermediate annealing (1040-1120°C) to relieve work hardening and restore ductility for subsequent processing.
Final Heat Treatment (Solution Annealing): Tubes receive final solution annealing at 1040-1120°C followed by rapid cooling to achieve specified mechanical properties, corrosion resistance, and grain structure. This is critical for TP321 to ensure titanium carbides are properly dissolved and reprecipitated.
Straightening & Cutting: Precision straightening to meet standard straightness tolerances (0.15% of total length), followed by cutting to exact ordered lengths with clean, burr-free ends.
Finishing & Surface Inspection: Visual examination to ensure freedom from surface defects such as cracks, folds, laps, and scabs. Pickling or bright annealing applied as final surface finish.
End Finishing: Plain ends (square cut), beveled ends (30-35° bevel angle with 1.6mm ±0.8mm landing), or threaded ends as per customer specification.
Quality Control & Testing Procedures
| Stage | Inspection Method | Purpose |
| Raw Material (Billet) | Chemical Analysis (OES Spectrometer) | Verify compliance with ASTM A213 TP321 composition limits (Cr, Ni, Ti, C, etc.) |
| Raw Material (Billet) | Tensile Testing at Room Temperature | Verify base material strength before processing |
| Raw Material (Billet) | Ultrasonic Testing (UT) | Detect internal laminations and defects |
| In-Process | Dimensional Inspection (Micrometers, Calipers) | Monitor OD, WT during drawing and rolling |
| In-Process | Surface Visual Inspection | Detect surface defects (folds, laps, cracks) |
| Finished Tube | Solution Annealing Verification | Ensure proper heat treatment (1040-1120°C, rapid cooling) |
| Finished Tube | Tensile Testing (Room & High Temp) | Verify yield strength (min 205 MPa), tensile strength (min 515 MPa), elongation (min 35%) |
| Finished Tube | Hardness Test (HRB / HV) | Verify maximum hardness 92 HRB / 210 HV |
| Finished Tube | Flaring Test | Verify ductility and soundness (tube end expanded with tapered mandrel) |
| Finished Tube | Flattening Test | Verify ductility and soundness (tube flattened between parallel plates) |
| Finished Tube | Hydrostatic Testing | Each tube pressure tested to specified pressure (no leakage permitted) |
| Finished Tube | Eddy Current Testing (ET) | Continuous on-line inspection for surface and subsurface defects |
| Finished Tube | Ultrasonic Testing (UT) | Full body inspection for internal defects (supplementary requirement) |
| Finished Tube | Intergranular Corrosion Test (Optional) | Verify resistance to sensitization (per ASTM A262 Practice E) |
| Finished Tube | Dimensional & Visual Inspection | Verify OD, WT, length, straightness, surface quality |
| Finished Tube | Marking Verification | Ensure permanent marking per ASTM A213 (standard, grade, size, heat number) |
Supplementary Tests (Upon Request):
High Temperature Tensile Test
Creep and Stress Rupture Test
Charpy Impact Test (for low temperature applications)
Grain Size Measurement (per ASTM E112)
Intergranular Corrosion Test per ASTM A262 (Practice E - Strauss test)
Ferrite Content Measurement (for duplex stainless steel)
Quality Documentation:
Mill Test Certificate per EN 10204 Type 3.1 or 3.2
Hydrostatic Test Report (tube-by-tube)
ET / UT Inspection Report
Flaring / Flattening Test Report
Traceability from heat number to finished tube
NACE MR0175 certification (upon request)
Primary Applications – ASTM A213 TP321 Stainless Steel Seamless Tube
ASTM A213 TP321 stainless steel seamless tubes are essential components in high temperature and corrosive service environments across various industries:
Power Generation: Superheater tubes, reheater tubes, boiler water wall tubes, steam headers, and main steam pipelines in thermal power plants, combined cycle units, and nuclear power plants (non-core). TP321's high temperature strength up to 816°C makes it ideal for supercritical boiler applications.
Industrial Boilers: Steam generation systems, hot water boilers, waste heat recovery boilers (WHRB), and heat recovery steam generators (HRSG) for manufacturing facilities. The titanium stabilization prevents sensitization during welding and service.
Petrochemical & Refining: Heat exchangers, process heaters, cracking furnaces (ethylene crackers), reformer tubes, and high temperature fluid transfer lines in refineries and petrochemical plants. TP321 resists polythionic acid stress corrosion cracking in refinery service.
Chemical Processing: Reactors, reformers, high temperature piping systems handling corrosive gases and liquids, and equipment for nitric acid, sulfuric acid, and organic chemical production.
High Temperature Headers: Steam headers and manifold systems operating at temperatures between 400-800°C where creep resistance and thermal stability are critical.
Furnace Tubes: Radiant tubes, convection section tubes, and transfer lines in industrial furnaces, thermal oxidizers, and incinerators.
Heat Exchangers: Shell and tube heat exchangers, U-tube bundles, and condenser tubes for high temperature and corrosive service.
Aerospace & Defense: High temperature hydraulic lines, engine bleed air systems, and exhaust system components requiring oxidation resistance up to 800°C.
Pharmaceutical & Food Processing: High temperature steam lines and sterile processing equipment where corrosion resistance and cleanability are essential.
Common International Standards for Stainless Steel Seamless Tubes
| Standard | Full Standard Name | Applicable Grades | Typical Application |
| ASTM A213 | Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes | TP304, TP304L, TP304H, TP309, TP310, TP316, TP316L, TP316H, TP316Ti, TP321, TP321H, TP347, TP347H | Boiler tubes, superheater tubes, heat exchanger tubes |
| ASTM A312 | Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes | TP304/L, TP316/L, TP321, TP347, TP904L | General service stainless steel pipes, pressure piping |
| ASTM A269 | Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubes for General Service | TP304/L, TP316/L, TP321, TP347 | General service tubing, instrumentation, mechanical applications |
| ASTM A789 | Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service | S31803 (2205), S32205, S32750 (2507), S32760 | Duplex stainless steel tubes, general service |
| ASTM A790 | Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe | S31803 (2205), S32205, S32750 (2507), S32760 | Duplex stainless steel pipes, pressure applications |
| EN 10216-5 | Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 5: Stainless steel tubes | 1.4301 (304), 1.4307 (304L), 1.4401 (316), 1.4404 (316L), 1.4541 (321), 1.4878 (321H), 1.4550 (347) | Pressure purposes, European market |
| EN 10305-1 | Steel tubes for precision applications - Technical delivery conditions - Part 1: Seamless cold drawn tubes | E215, E235, E355 (carbon steel) | Precision applications, hydraulic cylinders |
| EN 10216-2 | Seamless steel tubes for pressure purposes - Non-alloy and alloy steel tubes with specified elevated temperature properties | P235GH, P265GH, P295GH, P355GH (carbon/alloy) | Pressure purposes, elevated temperature |
| JIS G3459 | Stainless steel pipes | SUS304TP, SUS304LTP, SUS316TP, SUS316LTP, SUS321TP, SUS347TP | Stainless steel pipes, Japanese market |
| JIS G3463 | Stainless steel boiler and heat exchanger tubes | SUS304TKA, SUS316TKA, SUS321TKA, SUS347TKA | Boiler and heat exchanger tubes, Japanese market |
| GB/T 14976 | Seamless stainless steel pipes for fluid transport | 0Cr18Ni9 (304), 00Cr17Ni14Mo2 (316L), 1Cr18Ni9Ti (321) | Fluid transport, Chinese market |
| GB/T 14975 | Seamless stainless steel pipes for structural purposes | 0Cr18Ni9 (304), 1Cr18Ni9Ti (321) | Structural purposes, Chinese market |
| GB 13296 | Seamless stainless steel tubes for boiler and heat exchanger | 0Cr18Ni9 (304), 0Cr17Ni12Mo2 (316), 1Cr18Ni9Ti (321) | Boiler and heat exchanger, Chinese market |
| ISO 1127 | Stainless steel tubes - Dimensions, tolerances and conventional masses per unit length | — | Dimensional standard for stainless steel tubes |
| NACE MR0175 / ISO 15156 | Petroleum and natural gas industries - Materials for use in H₂S-containing environments in oil and gas production | 304/L, 316/L, 321, 347, 2205, 2507 | Sour service, oil and gas production |
Packaging & Shipping
Packaging:
Protective Covering: Individual plastic sleeves or spiral wrapping applied to each tube to prevent surface scratches and moisture contact.
Bundling: Tubes bundled together and secured with steel straps (3-5 straps per bundle) with protective corner guards. Wooden dunnage or foam rings between layers prevents abrasion.
End Caps: Plastic end caps (PE or PP) on both ends protect beveled/plain ends and threads from impact damage and debris ingress.
Wooden Crates: For high-value or precision orders, tubes packed in sturdy wooden crates or plywood cases for enhanced protection.
Desiccant Bags: Added for moisture-sensitive applications or long sea freight.
Shipping:
Mode of Transportation: Container vessels (20ft/40ft), bulk carriers (>500 tons), or air freight for sample shipments.
Containerization: Tubes loaded into standard containers. Max load: 20-25 tons per 20ft, 25-28 tons per 40ft.
Bulk Vessel Loading: Large orders loaded directly into bulk carriers with lifting beams, dunnage, and lashing to secure cargo.
Labeling & Documentation: Each bundle labeled with grade, standard, dimensions, heat number. Complete shipping documents (invoice, packing list, bill of lading, COO, MTC) prepared for customs clearance.
Secure Fastening: Bundles secured with steel strapping, dunnage bags, or timber bracing to prevent shifting during transit.
Tracking & Insurance: Container tracking numbers provided. Marine cargo insurance available upon request.
Packaging & Shipping
Packaging:
- Protective Covering: Individual plastic sleeves or spiral wrapping applied to each tube to prevent surface scratches and moisture contact.
- Bundling: Tubes bundled together and secured with steel straps (3-5 straps per bundle) with protective corner guards. Wooden dunnage or foam rings between layers prevents abrasion.
- End Caps: Plastic end caps (PE or PP) on both ends protect beveled/plain ends and threads from impact damage and debris ingress.
- Wooden Crates: For high-value or precision orders, tubes packed in sturdy wooden crates or plywood cases for enhanced protection.
- Desiccant Bags: Added for moisture-sensitive applications or long sea freight.
Shipping:
Mode of Transportation: Container vessels (20ft/40ft), bulk carriers (>500 tons), or air freight for sample shipments.
Containerization: Tubes loaded into standard containers. Max load: 20-25 tons per 20ft, 25-28 tons per 40ft.
Bulk Vessel Loading: Large orders loaded directly into bulk carriers with lifting beams, dunnage, and lashing to secure cargo.
Labeling & Documentation: Each bundle labeled with grade, standard, dimensions, heat number. Complete shipping documents (invoice, packing list, bill of lading, COO, MTC) prepared for customs clearance.
Secure Fastening: Bundles secured with steel strapping, dunnage bags, or timber bracing to prevent shifting during transit.
Tracking & Insurance: Container tracking numbers provided. Marine cargo insurance available upon request.
Common Industry Applications Summary
| Industry | Application | Recommended Grade |
| Power Generation | Superheater tubes, reheater tubes, boiler water walls, steam headers | TP321, TP321H, TP347H |
| Petrochemical | Ethylene cracking furnace tubes, reformer tubes, heat exchangers | TP321, TP321H, TP347 |
| Oil & Gas | High temperature piping, heat exchanger bundles, process heaters | TP321, TP316/L, 2205 |
| Chemical Processing | Reactors, high temperature piping, corrosive service | TP321, TP316/L, 904L |
| Pharmaceutical | High purity steam lines, sterile processing equipment | TP304/L, TP316/L (BA finish) |
| Food & Beverage | Processing equipment, high temperature steam lines | TP304/L, TP316/L (BA finish) |
| Refining | Crude heaters, vacuum heaters, catalytic crackers | TP321H, TP347H |
| Aerospace | High temperature hydraulic lines, exhaust systems | TP321, 17-4PH |
| Desalination | High temperature brine heaters, evaporators | TP316/L, 2205, 2507 |
| Pulp & Paper | Digester tubes, bleach plant piping, recovery boilers | TP316/L, 2205, 904L |
Womic Steel Advantages & FAQ
Why Partner with Womic Steel for Stainless Steel Seamless Tubes?
Complete Range of Grades: Full portfolio of austenitic (304/304L, 316/316L, 321/321H, 347/347H, 310S), duplex (2205, 2507), and super austenitic (904L) stainless steel seamless tubes under one roof.
Multiple Standard Compliance: ASTM A213, A312, A269, A789, A790, EN 10216-5, EN 10305-1, GB/T 14976, JIS G3459, JIS G3463. One supplier for multiple market requirements.
Precision Manufacturing: Cold drawn and cold rolled (pilgered) processes ensuring tight dimensional tolerances (±0.05mm for precision tubes) and superior surface finish (BA, mirror, brushed).
Full Traceability: Each tube traceable from heat number to finished product with complete documentation.
Value-Added Services: End beveling (30-35°), plain end cutting, threading, plastic caps installation, and surface finishing (BA, pickled, polished, mirror) available in-house.
Quality Assurance: 100% hydrostatic testing, eddy current testing (ET), optional ultrasonic testing (UT), flaring and flattening tests performed on every tube.
Third-Party Inspection: Facilitation of inspections by DNV, BV, SGS, TÜV, ABS, LR. 3.2 certificates supplied upon request.
Global Logistics: Strategic partnership with freight forwarders for optimized container loading and cost-effective worldwide shipping.
Technical Support: Engineering team available for material selection, grade substitution, and application consulting.
Choose Womic Steel Group as your reliable partner for high-quality ASTM A213 TP321 stainless steel seamless tubes and unbeatable delivery performance for boiler, heat exchanger, and petrochemical projects worldwide. Welcome to inquire!
Website: www.womicsteel.com
Email: sales@womicsteel.com
Tel/WhatsApp/WeChat:
Victor: +86-15575100681
Jack: +86-18390957568
Frequently Asked Questions (FAQ)
Q: What is the difference between TP321 and TP304 stainless steel?
A: TP321 is titanium-stabilized, offering superior resistance to intergranular corrosion after welding or high temperature exposure (425-850°C). TP304 is unstabilized and may become sensitized in this temperature range, leading to intergranular corrosion. TP321 also has higher high-temperature strength and creep resistance, with maximum service temperature of 816°C vs 427°C for TP304L .
Q: What is the difference between TP321 and TP321H?
A: TP321 has maximum carbon of 0.08%, while TP321H has controlled carbon between 0.04-0.10%. The higher carbon content in TP321H provides improved high-temperature strength, creep resistance, and stress rupture properties for prolonged service above 500°C. TP321H is specifically intended for superheater and reheater applications .
Q: Why is titanium added to TP321 stainless steel?
A: Titanium has a higher affinity for carbon than chromium. When exposed to high temperatures (425-850°C), titanium forms titanium carbides (TiC) instead of allowing chromium carbides to form at grain boundaries. This prevents chromium depletion and maintains corrosion resistance - a process called "stabilization" .
Q: What is the maximum operating temperature for TP321?
A: Per ASME Boiler and Pressure Vessel Code, TP321 has a maximum use temperature of 1500°F (816°C). This is significantly higher than TP304L (800°F/427°C). TP321H offers similar temperature capability with improved creep strength .
Q: What applications is TP321 best suited for?
A: Boiler tubes, superheaters, reheaters, heat exchangers, high temperature steam headers, furnace tubes, petrochemical crackers, refinery heaters, thermal oxidizers, waste heat recovery units, and any high temperature application where sensitization and intergranular corrosion are concerns .
Q: Can TP321 be used in the as-welded condition without post-weld heat treatment?
A: Yes. Due to titanium stabilization, TP321 does not require post-weld heat treatment (PWHT) to restore corrosion resistance. The material remains resistant to intergranular corrosion even in the as-welded condition, making it ideal for field fabrication .
Q: What is the difference between cold drawn and cold rolled seamless tubes?
A: Cold drawn tubes are produced by pulling the tube through a die, offering precise OD control. Cold rolled (pilgered) tubes are processed using a cold rolling mill, providing greater wall thickness reduction and improved surface finish. Both processes produce seamless tubes meeting ASTM A213 requirements .
Q: What non-destructive testing (NDT) is available for TP321 tubes?
A: Hydrostatic testing (each tube), eddy current testing (ET), ultrasonic testing (UT), and optional supplementary requirements including flaring test and flattening test. Standard specification requires one of these tests - either hydrostatic or eddy current .
Q: Can you provide third-party inspection for TP321 tubes?
A: Yes. Inspections by DNV, BV, SGS, TÜV, ABS, LR available. 3.2 inspection certificates validated by authorized third parties supplied upon request. Witnessing of mechanical testing, NDT, and dimensional inspection available.
Q: What is the typical lead time for ASTM A213 TP321 seamless tubes?
A: Stock sizes (common diameters like 19mm, 25.4mm, 38mm, 50.8mm): 15-25 days. Custom sizes: 30-45 days. Special requirements (3.2 certification, third-party inspection) add 10-15 days.
Q: What documentation do you provide with TP321 tube shipments?
A: Mill Test Certificate (EN 10204 Type 3.1 or 3.2), chemical composition report, tensile test report, hydrostatic test report, flaring/flattening test report (if specified), NDT report (UT/ET), dimensional report, packing list, commercial invoice, bill of lading.
Q: Is TP321 suitable for high pressure boiler applications?
A: Yes. TP321 is widely used for superheater and reheater tubes in high pressure boilers, as well as for steam headers and high temperature piping in power generation. The material offers excellent creep resistance and high temperature strength for prolonged service under pressure .
Q: What surface finishes are available for TP321 seamless tubes?
A: Annealed and pickled (standard, removes scale and provides clean surface), bright annealed (BA - provides reflective surface with minimal scale, ideal for food and pharmaceutical applications), and polished (mechanical or manual polishing to various grit finishes) .
Q: How does TP321 compare to TP347?
A: Both are stabilized grades. TP321 uses titanium stabilization, TP347 uses columbium/tantalum. TP347 is somewhat more resistant to general corrosion in strongly oxidizing environments and may be preferred for aqueous and low temperature environments. TP321 is more common and cost-effective for most high temperature applications .
Q: Is TP321 suitable for sour service (H₂S environments)?
A: Yes, with NACE MR0175 / ISO 15156 certification. The material must meet specific hardness requirements (≤ 22 HRC / ≤ 248 HV) and be supplied in the solution annealed condition. Please specify sour service requirements at time of quotation.
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Inconel 601 (UNS N06601) – Nickel-Chromium Allo...