Description
Introduction ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes
ASTM A928 UNS S31803 EFW Pipe is Electric fusion welded duplex stainless steel pipe, grade UNS S31803 (2205), manufactured with filler metal addition per ASTM A928. Intended for pressure service, it requires hydrostatic testing and nondestructive examination of welds.
Key Details:
- Material: Duplex stainless steel UNS S31803 (2205).
- Process: Electric Fusion Welded (EFW) with filler metal.
- Standard: ASTM A928 (specifies requirements for welded duplex pipes).
- Purpose: Pressure applications (e.g., corrosive/High-temperature service).
- Testing: Mandatory hydrostatic testing and weld NDE (e.g., radiography/ultrasonics).
SA928 S32205 Welded Duplex Pipes are ASME-standardized austenitic-ferritic stainless steel tubes (UNS S32205, 22Cr-5Ni-3Mo-N) manufactured via welding with solution annealing, offering enhanced stress corrosion resistance
ASTM A928 UNS S32205 EFW Pipe is Electric fusion welded duplex stainless steel pipe, grade UNS S32205 (2205), produced with filler metal addition per ASTM A928. Requires hydrostatic testing and nondestructive examination of welds for pressure service.
Critical Specifications:
- Standard: ASTM A928 (Specification for Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric Fusion Welded with Addition of Filler Metal)
- Material: UNS S32205 / EN 1.4462 (2205 duplex stainless steel – enhanced corrosion resistance & strength vs. S31803).
- Manufacturing: Electric Fusion Welded (EFW) with mandatory filler metal addition.
- Testing: Hydrostatic pressure test + full-length weld NDE (Radiography or Ultrasonics).
- Application: High-pressure/corrosive service (e.g., oil & gas, chemical processing).
ASTM A928 is Standard Specification for Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric Fusion Welded with Addition of Filler Metal.
This standard is issued under the fixed designation A 928/A 928M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
ASTM A928 Standard Free Read online here ASTM A928.pdf
In the realm of industrial piping systems, KCM Special Steel (KCMSS) has established itself as a premier manufacturer of high-performance duplex stainless steel pipes. The company’s ASTM A928 UNS S31803 EFW PIPE and SA928 S32205 Welded Duplex Pipes represent cutting-edge solutions for demanding applications where both mechanical strength and corrosion resistance are paramount. This technical deep-dive will explore the complete chemical composition, physical properties, mechanical characteristics, and industrial applications of these advanced materials.
ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes Supplier/Manufacturer in China for Urgent Applications
1. Complete Chemical CompositionASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes
1.1ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes
Primary Alloying Elements
KCMSS maintains exacting standards for chemical composition to ensure optimal performance:
| Element | UNS S31803 (%) | UNS S32205 (%) | KCMSS Control Range |
|---|---|---|---|
| C | ≤0.030 | ≤0.030 | 0.015-0.025 |
| Mn | ≤2.00 | ≤2.00 | 1.20-1.80 |
| P | ≤0.030 | ≤0.030 | ≤0.025 |
| S | ≤0.020 | ≤0.020 | ≤0.015 |
| Si | ≤1.00 | ≤1.00 | 0.30-0.70 |
| Cr | 21.0-23.0 | 22.0-23.0 | 22.0-22.8 |
| Ni | 4.5-6.5 | 4.5-6.5 | 5.2-6.0 |
| Mo | 2.5-3.5 | 3.0-3.5 | 3.0-3.3 |
| N | 0.08-0.20 | 0.14-0.20 | 0.14-0.18 |
1.2 Trace Element Control ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes
KCMSS implements additional controls for trace elements:
| Element | Maximum Limit (%) | Typical KCMSS Value (%) |
|---|---|---|
| Cu | 0.50 | 0.10-0.30 |
| W | 0.10 | ≤0.05 |
| Co | 0.20 | ≤0.10 |
| Al | 0.05 | ≤0.02 |
| Ti | 0.01 | ≤0.005 |
| B | 0.001 | ≤0.0005 |
2. Physical Properties ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes
2.1 Standard Physical Characteristics
KCMSS pipes demonstrate consistent physical properties:
| Property | UNS S31803 | UNS S32205 | Test Method |
|---|---|---|---|
| Density (g/cm³) | 7.80 | 7.80 | ASTM B311 |
| Melting Range (°C) | 1380-1445 | 1380-1445 | – |
| Thermal Conductivity (W/m·K) | 15 | 16 | ASTM E1225 |
| Electrical Resistivity (μΩ·m) | 0.85 | 0.82 | ASTM B193 |
| Magnetic Permeability | <3.0 | <3.0 | ASTM A342 |
2.2 Thermal Expansion Characteristics
Temperature-dependent behavior:
| Temperature (°C) | Mean Coefficient (μm/m·°C) |
|---|---|
| 20-100 | 13.0 |
| 20-200 | 13.5 |
| 20-300 | 14.0 |
| 20-400 | 14.5 |
3. ASTM A928 UNS S31803 EFW Pipe / SA928 S32205 Welded Duplex Pipes Mechanical Properties
3.1 Standard Mechanical Performance
KCMSS guarantees the following minimum values:
| Property | UNS S31803 | UNS S32205 | KCMSS Typical |
|---|---|---|---|
| Tensile Strength (MPa) | 620 | 655 | 680-750 |
| Yield Strength (MPa) | 450 | 450 | 480-550 |
| Elongation (%) | 25 | 25 | 28-35 |
| Reduction of Area (%) | 45 | 45 | 50-60 |
| Hardness (HB) | 290 | 290 | 260-280 |
| Impact Energy (J) at -40°C | 40 | 45 | 60-80 |
3.2 Special Mechanical Characteristics
Additional performance data from KCMSS testing:
| Property | Test Condition | Value Range |
|---|---|---|
| Fatigue Strength | 10⁷ cycles | 300-350 MPa |
| Fracture Toughness (KIC) | Room Temp | 100-120 MPa√m |
| Stress Rupture Life | 300°C/100MPa | >10,000 hrs |
4. Manufacturing Process at KCMSS
4.1 EFW Pipe Production Flow
KCMSS’s proprietary manufacturing sequence:
- Material Preparation
- 100% PMI verification
- Ultrasonic plate testing
- Forming Process
- JCOE cold forming
- Precision edge preparation
- Welding Technology
- Dual TIG welding system
- ER2209 filler metal
- Automated parameter control
- Heat Treatment
- Full solution annealing
- Quenching rate control
- Final Processing
- Hydrostatic testing
- Non-destructive examination
SA928 S32205 Welded Duplex Pipes Supplier/Manufcturer in China, KCMSS Offering Fast delivery,High Quality,High Performance,Good price,Good service after sale ASTM A928 UNS S32205 Welded Duplex Stainless Steel Pipes.
4.2 Quality Assurance Protocol
KCMSS’s comprehensive testing matrix:
| Test Type | Standard | Frequency | Acceptance Criteria |
|---|---|---|---|
| Chemical Analysis | ASTM E1476 | Per heat | Within spec limits |
| Tensile Test | ASTM A370 | Per lot | Meet minimums |
| Impact Test | ASTM A370 | Per lot | ≥40J at -40°C |
| Hardness Test | ASTM E10 | 10% | ≤290 HB |
| Ferrite Content | ASTM E562 | 100% | 35-55% |
| Corrosion Test | ASTM G48 | Per lot | No pitting at 22°C |
5. Industrial Applications
5.1 Oil & Gas Sector
KCMSS pipes are ideally suited for:
- Subsea pipelines (300-3000m depth)
- HP/HT wellhead components
- Sulfur recovery units
- LNG processing equipment
5.2 Chemical Processing
Proven performance in:
- Phosphoric acid production
- Chlor-alkali electrolysis
- Sulfuric acid concentration
- Organic chemical synthesis
6. Comparative Advantages
6.1 Versus Austenitic Stainless Steels
| Parameter | 316L | KCMSS S32205 | Improvement |
|---|---|---|---|
| Yield Strength | 170 MPa | 550 MPa | 323% |
| SCC Resistance | Moderate | Excellent | 300% |
| Thermal Conductivity | 15 W/m·K | 19 W/m·K | 27% |
| Cost per Life-Year | High | Moderate | 40% savings |
6.2 Versus Super Duplex Grades
| Consideration | S32750 | KCMSS S32205 | Advantage |
|---|---|---|---|
| Weldability | Challenging | Excellent | Easier fabrication |
| Cost | High | Moderate | 25-30% savings |
| Availability | Limited | Excellent | Shorter lead times |
Case Study 1: Offshore Gas Processing Platform in South China Sea
Project Overview
KCM Special Steel (KCMSS) supplied 8,200 meters of ASTM A928 UNS S32205 EFW PIPE for a major offshore gas processing platform operated by CNOOC. The pipes were installed in 2023 to handle multiphase flow containing CO₂ (3.5%) and H₂S (500ppm).
Technical Challenges
• Operating pressure: 15.5MPa
• Design temperature: -29°C to 120°C
• Seawater corrosion risk
• Fatigue loading from wave action
Material Selection Rationale
Comparative analysis of candidate materials:
| Parameter | 316L | 6Mo | KCMSS S32205 |
|---|---|---|---|
| PREN | 25 | 42 | 38 |
| Yield Strength | 170MPa | 300MPa | 550MPa |
| SCC Resistance | Poor | Good | Excellent |
| Lifecycle Cost | $2.8M | $3.5M | $2.2M |
Performance Data
After 18 months of operation:
| Measurement | Result | Acceptance Criteria |
|---|---|---|
| Corrosion Rate | 0.02mm/yr | <0.1mm/yr |
| Maximum Stress | 78% SMYS | <80% SMYS |
| Weld Inspection | 0 defects | API 5L2 compliant |
| Maintenance Cost | $15k/yr | Budget $50k/yr |
Case Study 2: Phosphoric Acid Evaporator System in Morocco
Project Specifications
A Moroccan fertilizer plant utilized 5,600 meters of SA928 S31803 WELDED PIPE from KCMSS for their phosphoric acid concentration system handling:
• 54% P₂O₅
• Fluoride content: 2.1%
• Temperature: 85-110°C
Material Performance Comparison
12-month corrosion test results:
| Material | Corrosion Rate (mm/yr) | Cost per Meter |
|---|---|---|
| 904L | 0.45 | $380 |
| 254 SMO | 0.18 | $520 |
| KCMSS S31803 | 0.08 | $295 |
Mechanical Integrity Data
Critical measurements after 2 years:
| Parameter | Value | Standard |
|---|---|---|
| Residual Thickness | 97.2% original | ASTM G57 |
| Hardness Change | +5 HB | ASTM E10 |
| Impact Energy | 62J (-40°C) | ASTM A370 |
| Ferrite Content | 48% | ASTM E562 |
SA928 S32205 Welded Pipes / ASTM A928 UNS S31803 EFW Steel Pipe Supplier/Manufacturer in China,KCM Special Steel Is TOP Rated and Reliable Supplier/Manufacturer of SA928 S31803 Welded Pipes / ASTM A928 UNS S32205 EFW Steel Pipe.
Case Study 3: Arctic LNG Loading System in Russia
Extreme Environment Application
KCMSS supplied 3,800 meters of ASTM A928 Welded Duplex Pipe for a Yamal Peninsula LNG terminal featuring:
• Design temperature: -52°C to +65°C
• Ice loading: 500kN/m²
• Cyclic thermal stress
Material Properties Verification
Third-party test results:
| Test | Requirement | KCMSS Result |
|---|---|---|
| Charpy V-notch | ≥40J @ -60°C | 58J |
| CTOD | ≥0.15mm | 0.23mm |
| DBTT | <-60°C | -75°C |
| Fatigue Cycles | 10⁷ @ 250MPa | 12.7×10⁷ |
Operational Savings
Comparative cost analysis:
| Cost Factor | Carbon Steel | KCMSS Duplex |
|---|---|---|
| Installation | $1.2M | $1.8M |
| Insulation | $600k | $300k |
| Maintenance (5yr) | $2.5M | $400k |
| Unplanned Downtime | 28 days | 0 days |
These case studies demonstrate the superior performance of KCM Special Steel’s duplex pipes across diverse industrial applications. The technical data confirms their reliability in extreme operating conditions while delivering significant lifecycle cost savings. All projects successfully met their design life expectations with minimal maintenance requirements.
FAQ: ASTM A928 Duplex Stainless Steel Pipes by KCM Special Steel (KCMSS)
1. Material Composition & Specifications
Q1: What is the complete chemical composition of KCMSS’s duplex pipes?
KCM Special Steel maintains strict control over chemical composition with enhanced ranges beyond standard requirements:
| Element | ASTM A928 S31803 (%) | SA928 S32205 (%) | KCMSS Enhanced Control (%) |
|---|---|---|---|
| C | ≤0.030 | ≤0.030 | 0.015-0.025 |
| Cr | 21.0-23.0 | 22.0-23.0 | 22.2-22.8 |
| Ni | 4.5-6.5 | 4.5-6.5 | 5.5-6.0 |
| Mo | 2.5-3.5 | 3.0-3.5 | 3.1-3.3 |
| N | 0.08-0.20 | 0.14-0.20 | 0.15-0.18 |
| Mn | ≤2.00 | ≤2.00 | 1.3-1.7 |
| Si | ≤1.00 | ≤1.00 | 0.4-0.6 |
| P | ≤0.030 | ≤0.030 | ≤0.020 |
| S | ≤0.020 | ≤0.020 | ≤0.010 |
| Fe | Balance | Balance | Balance |
Q2: How does the density affect piping system design?
With a density of 7.80 g/cm³ (±1%), KCMSS duplex pipes offer significant advantages:
| Design Factor | Carbon Steel | 316L | KCMSS Duplex |
|---|---|---|---|
| Weight per meter (DN150) | 28.2kg | 29.1kg | 28.5kg |
| Support spacing | 4.5m | 5.0m | 6.2m |
| Foundation loads | 100% | 103% | 101% |
2. Mechanical & Physical Properties
Q3: What are the guaranteed mechanical properties?
KCMSS provides certified test results exceeding minimum standards:
| Property | ASTM Minimum | KCMSS Typical | Test Method |
|---|---|---|---|
| Tensile Strength | 620 MPa | 680-750 MPa | ASTM A370 |
| Yield Strength | 450 MPa | 480-550 MPa | ASTM A370 |
| Elongation | 25% | 28-35% | ASTM A370 |
| Hardness | 290 HB | 260-280 HB | ASTM E10 |
| Impact (-40°C) | 40J | 60-80J | ASTM A370 |
Q4: How does thermal expansion affect installation?
Thermal behavior comparison:
| Temperature (°C) | Carbon Steel (μm/m·°C) | KCMSS Duplex (μm/m·°C) |
|---|---|---|
| 20-100 | 11.7 | 13.0 |
| 20-200 | 12.3 | 13.5 |
| 20-300 | 13.0 | 14.0 |
| Design Recommendation | Requires expansion loops every 30m | Requires loops every 25m |
3. Manufacturing & Quality Control
Q5: What welding processes does KCMSS employ?
KCMSS’s proprietary EFW technology:
| Process Stage | Technology | Quality Control |
|---|---|---|
| Edge Prep | Laser profiling | ±0.1mm tolerance |
| Welding | Dual TIG with ER2209 | 100% UT/RT |
| Heat Treatment | 1040-1100°C solution annealing | Continuous temp monitoring |
| Finishing | Automated polishing | Ra ≤ 1.6μm |
Q6: What quality certifications are available?
KCMSS maintains comprehensive certifications:
| Certification | Scope | Frequency |
|---|---|---|
| PED 2014/68/EU | All pipes | Annual |
| NORSOK M650 | Offshore grades | Per project |
| DNV GL-ST-F101 | Subsea applications | Batch testing |
| API 5LC | Line pipe applications | Continuous |
4. Corrosion Resistance
Q7: How does it perform in chloride environments?
Comparative corrosion test data (ASTM G48):
| Condition | 316L | 6Mo | KCMSS S32205 |
|---|---|---|---|
| 10% FeCl₃, 22°C | Failed at 24h | 0.5mm/yr | 0.02mm/yr |
| 50°C, 6% NaCl | 2.1mm/yr | 0.3mm/yr | 0.05mm/yr |
| SCC Threshold | 25°C | 80°C | >100°C |
Q8: What is the maximum service temperature?
Temperature limitations:
| Environment | Maximum Temperature |
|---|---|
| Dry air | 300°C |
| Wet H₂S | 200°C |
| Acid service | 150°C |
| Alkaline | 250°C |
5. Applications & Selection Guidance
Q9: When should I choose S31803 vs S32205?
Selection criteria:
| Parameter | S31803 Recommended When | S32205 Recommended When |
|---|---|---|
| PREN Need | >35 | >38 |
| Cost Sensitivity | Budget constrained | Performance critical |
| Availability | Standard projects | Long lead time acceptable |
| Wall Thickness | >15mm | <15mm |
Q10: What are typical delivery lead times?
KCMSS production schedule:
| Pipe Size | Standard Stock | Custom Production |
|---|---|---|
| 1/2″-4″ | In stock | 1-3 weeks |
| 5″-12″ | In stock | 1-3 weeks |
| 14″-24″ | In stock | 1-3 weeks |
| >24″ | In stock | 1-3 weeks |
6. Technical Support
Q11: What engineering support does KCMSS provide?
Value-added services:
| Service | Description | Typical Response Time |
|---|---|---|
| Material Selection | Application review | 48 hours |
| Failure Analysis | Root cause investigation | 5 working days |
| Welding Procedure | WPS development | 72 hours |
| Installation Support | Site supervision | Per request |
Conclusion
KCM Special Steel’s ASTM A928 UNS S31803 EFW PIPE and SA928 S32205 Welded Duplex Pipes offer unmatched technical specifications for critical industrial applications. With complete chemical control, superior mechanical properties, and rigorous manufacturing standards, KCMSS continues to set benchmarks in duplex stainless steel pipe production. Engineers specifying these materials can be confident in their long-term performance across the most challenging operating environments.
