AWS Class E91T1-B3 Flux Core
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E91T1-B3 Flux Cored Wire Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier and importer of E91T1-B3 chrome-moly flux cored wire in Mumbai, India. We supply E91T1-B3C and E91T1-B3M classifications in compliance with the AWS A5.29 / ASME SFA 5.29.
E91T1-B3 flux cored wire deposits consist of ~2.27% Cr and 1.03% Mo, matching all ASME P-5A Group 1 and 2 base metals. AWS A5.29 E91T1-B3 flux-cored wire delivers the precisely matched 2.25Cr-1Mo chemistry that SA335 P22 piping and SA387 Gr 22 plate demand for creep-critical service up to 600°C (1112°F). After mandatory PWHT, minimum tensile strength reaches 90 ksi (620 MPa) with yield at 78 ksi (540 MPa) and elongation of 17%. When process temperatures go beyond the 550°C limit of 1.25Cr-0.5Mo piping, the refinery and power generation industries prefer 2.25Cr-1Mo steel, and the weld deposit must follow. Available diameters are 0.9 mm (0.035″), 1.2 mm (0.045″), 1.4 mm (0.052″), and 1.6 mm (1/16″). The B3C variant uses 100% CO₂, while B3M uses 75–80% Ar / 20–25% CO₂. All-position capability on DCEP with increased deposition rates, greater tolerance of mill scale and rust, and low spatter emission make this CrMo2 FCAW wire a direct productivity upgrade over other electrodes.
Key industries include oil and gas refining, supercritical/USC power generation, petrochemical, fertiliser (ammonia/urea), and HRSG fabrication. Every spool ships with EN 10204/3.1B mill test certificates and PMI reports. As a P22 welding wire supplier in India, we maintain a ready stock for immediate dispatch.
E91T1-B3 Flux Core Specifications
E91T1-B3 specification details covering AWS specification, process data, shielding gas options, ASME IX variables, and matching consumables are listed below.
| AWS Specification | AWS A5.29/A5.29M:2010 |
|---|---|
| ASME SFA | SFA 5.29 |
| Welding Process | FCAW-G |
| Flux Type | Rutile (Titania-based) |
| Polarity | DCEP |
| Positions | All (F, H, V-Up, OH) |
| Shielding Gas |
B3C: 100% CO₂, 35–45 cfh B3M: 75–80% Ar / 20–25% CO₂, 35–45 cfh |
| Available Diameters | 0.9 mm (0.035″), 1.2 mm (0.045″), 1.4 mm (0.052″), 1.6 mm (1/16″) |
| CTWD | 10–25 mm (3/8″ to 1″) |
| Spool Sizes | 5 kg, 12.5 kg, 15 kg (33 lb) |
| Max Service Temperature | 600°C (1112°F) for creep service |
AWS A5.29 Classification: E91T1-B3C and E91T1-B3M
The E91T1-B3 classification follows the AWS A5.29 low-alloy steel flux cored electrode designation system. Each character carries a specific technical meaning for WPS documentation and filler metal selection.
| Designator | E91T1-B3 Meaning |
|---|---|
| E | Electrode |
| 9 | 90 ksi (620 MPa) minimum tensile strength |
| 1 | All-position usability |
| T | Tubular (flux cored) |
| 1 | Rutile, DCEP, gas-shielded |
| B3 | 2.0–2.5% Cr, 0.90–1.20% Mo (2.25Cr-1Mo alloy system) |
| C or M | CO₂ (C) or 75–80% Ar / 20–25% CO₂ mixed gas (M) |
The B3 designation means the deposit matches 2.25Cr-1Mo for ASME P-5A base metals. The “9” digit reflects 90 ksi (620 MPa) minimum strength after PWHT, with a range of 90–110 ksi (620–760 MPa). E91T1-B3C and E91T1-B3M are the same wire under different shielding gases (a single spool may carry dual classification). The optional H4 hydrogen designator (≤4 mL/100 g) is critical for thick-section P-5A welding.
Chemical Composition of E91T1-B3 Weld Deposit (%)
The table below provides the chemical composition of E91T1-B3 and the key alloying elements as per AWS A5.29 requirements:
| Element | Carbon (C) | Manganese (Mn) | Silicon (Si) | Chromium (Cr) | Molybdenum (Mo) | Phosphorus (P) | Sulfur (S) | Nickel (Ni) | Vanadium (V) |
|---|---|---|---|---|---|---|---|---|---|
| AWS A5.29 Requirement | 0.05–0.12 | 1.25 max | 0.80 max | 2.00–2.50 | 0.90–1.20 | 0.03 max | 0.03 max | — | — |
| Typical | 0.065 | 1.18 | 0.51 | 2.27 | 1.03 | 0.014 | 0.011 | ≤0.20 (residual) | ≤0.05 (residual) |
The Cr/Mo ratio of approximately 2.2:1 balances oxidation resistance (Cr-dependent) with carbide stability (Mo-dependent).
Mechanical Properties of E91T1-B3 Weld Deposit (After PWHT)
The mechanical properties of E91T1-B3, including tensile and yield strength, elongation, and more, after mandatory PWHT at 690±15°C, are provided in the table below.
| Property | Tensile Strength | Yield Strength (0.2%) | Elongation (%) | Charpy V-Notch |
|---|---|---|---|---|
| AWS A5.29 Requirement (PWHT) | 90,000–110,000 psi (620–760 MPa) | ≥78,000 psi (540 MPa) | ≥17% | Not required by AWS for B3 |
| Typical (Washington Alloy) | 98,900 psi (682 MPa) | 87,700 psi (605 MPa) | 27% | ~70 J at +20°C (Böhler typical) |
Minimum yield of 78 ksi (540 MPa) for B3 exceeds B2’s 68 ksi by 15%. Insufficient tempering may result in excessively high hardness and reduced ductility, which is unacceptable for Cr-Mo pressure service.
Base Metal Compatibility & ASME P-Number Matrix for E91T1-B3
E91T1-B3 is classified as F-6 / A-5 under ASME Section IX. It matches all P-5A Group 1 and 2 base metals and is also used for P-5A to P-4 transition joints.
| Base Metal Spec. | Grade | ASME P-No. | Cr-Mo Content | Typical Application |
|---|---|---|---|---|
| SA335 / A335 | P22 | P-5A Grp 1 | 2.25Cr-1Mo | Seamless pipe (main steam, hot reheat) |
| SA213 / A213 | T22 | P-5A Grp 1 | 2.25Cr-1Mo | Boiler/superheater tube |
| SA387 / A387 | Gr 22 Cl.1/2 | P-5A Grp 1/2 | 2.25Cr-1Mo | Pressure vessel plate |
| SA182 / A182 | F22 Cl.1/3 | P-5A Grp 1/2 | 2.25Cr-1Mo | Forged fittings, flanges |
| SA336 / A336 | F22 Cl.1/3 | P-5A | 2.25Cr-1Mo | Forged nozzles |
| SA369 / A369 | FP22 | P-5A | 2.25Cr-1Mo | Forged pipe |
| SA426 / A426 | CP22 | P-5A | 2.25Cr-1Mo | Centrifugally cast pipe |
| SA542 / A542 | Types A–E | P-5A Grp 2/3 | 2.25Cr-1Mo (Q&T) | Reactor shells |
For dissimilar joints between P-5A (P22) and P-4 (P11), E91T1-B3 is used to match the higher-alloy side. E91T1-B3 must not be used for P-15E / Grade 91 (9Cr-1Mo-V) base metals.
Welding Parameters, Preheat & PWHT Requirements for E91T1-B3
With nearly double the alloy content of B2, E91T1-B3 develops a harder as-welded microstructure. Strict compliance with preheat and PWHT is non-negotiable.
| Diameter | Wire Speed (ipm) | Current (A) | Voltage (V) | CTWD |
|---|---|---|---|---|
| 0.035″ (0.9 mm) | 450–675 | 100–260 | 21–28 | 3/8–3/4″ |
| 0.045″ (1.2 mm) | 150–575 | 100–300 | 24–30 | 1/2–3/4″ |
| 0.052″ (1.4 mm) | 295–515 | 210–350 | 26–32 | 1/2–1″ |
| 1/16″ (1.6 mm) | 260–430 | 225–410 | 27–33 | 1/2–1″ |
Mandatory Preheat: 150–200°C (300°F−400°F) minimum, depending on thickness. Maximum interpass: 300–350°C. Do not let the weld cool below preheat between passes.
Mandatory PWHT: 680–730°C (1250–1355°F), hold 1 hour per 25 mm. Heating rate: ≤200°C/hr above 315°C. Cooling rate: ≤260°C/hr to 315°C, then air cool. For sections >50 mm, a hydrogen bake-out at 250–300°C for 2–4 hours is recommended before cooling to ambient.
Mandatory PWHT: 680–730°C (1250–1355°F), hold 1 hour per 25 mm. Heating rate: ≤200°C/hr above 315°C. Cooling rate: ≤260°C/hr to 315°C, then air cool. For sections >50 mm, a hydrogen bake-out at 250–300°C for 2–4 hours is recommended before cooling to ambient.
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Industrial Applications of E91T1-B3 Flux-Cored Welding Wire
E91T1-B3 flux-cored wire serves industries where 2.25Cr-1Mo steel forms the pressure boundary of high-temperature, high-pressure process equipment. The six key sectors are refinery hydroprocessing, supercritical power generation, petrochemical, fertiliser, HRSG fabrication, and heavy-wall pressure vessel work.
- Hydrocracker reactor shells (SA387 Gr 22 plate, 100–250 mm thick), reactor effluent piping (SA335 P22), hot separator vessels, and charge/effluent exchangers.
- Main steam piping (SA335 P22) in supercritical and USC boiler systems at 540–580°C / 250+ bar. Thick-wall headers (SA182 F22) and manifolds.
- Catalytic reformer piping, hydrogen plant reactor tubes, and high-temperature heat exchangers in ammonia and methanol synthesis.
- High-pressure synthesis loop piping, ammonia converter shells, and urea reactor components fabricated from 2.25Cr-1Mo steel. Service involves high-temperature, high-pressure hydrogen-nitrogen mixtures.
- Heat recovery steam generator (HRSG) headers, manifolds, and thick-wall piping from P22 material in combined cycle gas turbine plants. E91T1-B3 FCAW accelerates fabrication of these heavy-wall components during tight EPC schedules.
- Thick-wall vessels from SA387 Gr 22 Cl.2 (Q&T) plate for hydroprocessing reactors, high-pressure separators, and thermal cracking drums.
Storage, Handling & Hydrogen Control for E91T1-B3
The 2.25Cr-1Mo deposit from E91T1-B3 is more hardenable than the 1.25Cr-0.5Mo deposit from E81T1-B2, making it even more sensitive to hydrogen-induced cold cracking. Hydrogen control is the single most critical quality parameter for B3 wire storage and handling.
Store sealed spools at 15–25°C, RH below 50%. After opening, use promptly or keep in a heated cabinet at 40–60°C. Rebaking is not possible for FCAW wire. Vacuum-sealed moisture-barrier packaging is standard.
Quality documentation includes MTC 3.1 per EN 10204, ISO 9001, and ISO 14001 certification. CVN testing at specified cryogenic temperatures is available on request. CWB approval is confirmed for 0.045” diameter with M21 (75%Ar/25%CO₂) gas.
How to Order E91T1-B3 Flux Core from Nicorex Alloys
Provide the following details when requesting a quotation for E91T1-B3 flux core from Nicorex Alloys:
- Wire Type — FCAW-G Tubular Wire for 2.25Cr-1Mo Creep-Resistant Steel (E91T1-B3)
- Size — Diameter: 1.2mm / 1.6mm — specify spool size (5 kg / 15 kg)
- Shielding Gas — B3C: 100% CO₂ / B3M: 75–80% Ar + 20–25% CO₂ ISO — specify suffix
- Current Type — DCEP — specify wire feed speed and voltage per diameter
- Welding Position — All Positions — specify if positional welding is required
- Material Grade — 2.25Cr-1Mo Low Alloy FCAW Wire / AWS A5.29: E91T1-B3 / ASME SFA 5.29 ISO
- Quantity — Number of spools or total weight in kg
- Standard — AWS A5.29 / ASME SFA 5.29, EN ISO 17634-A, ASME Section IX, ASME B31.1
- Delivery — Domestic / International (specify port of discharge or delivery address)
Nicorex Alloys stocks the complete matching set: E91T1-B3 FCAW + ER90S-B3 GTAW + E9018-B3 SMAW.
Frequently Asked Questions
What is the Difference Between E91T1-B3 and E81T1-B2 in Service Temperature and Base Metal Selection?
E81T1-B2 matches 1.25Cr-0.5Mo (P-4) with a creep limit of 550°C. E91T1-B3 matches 2.25Cr-1Mo (P-5A) with service to 600°C. The doubled chromium gives better sulfidation and HTHA resistance.
What ASTM Grades of 2.25Cr-1Mo Steel can be Welded with E91T1-B3?
E91T1-B3 is specified for all ASME P-5A Group 1 and 2 base metals: SA335 P22, SA213 T22, SA387 Gr 22 (Cl.1/2), SA182 F22, SA336 F22, SA369 FP22, SA426 CP22, and SA542
Can E91T1-B3 be used for Transition Joints between P22 and P11 Piping?
Yes. For dissimilar P-5A to P-4 joints, E91T1-B3 is the standard filler because it matches the higher-alloy side.
What is the Maximum As-Welded Hardness of E91T1-B3, and Why does it Matter?
As-welded hardness typically reaches 350–420 HV. PWHT at 680–730°C tempers the microstructure to 200–250 HV, producing ductile tempered bainite. Hardness surveys across weld, HAZ, and base metal are mandatory quality verification for all P-5A welding.
When not to Use E91T1-B3 Flux Cored Wire?
E91T1-B3 should not be used for P-4 base metals (1.25Cr-0.5Mo, such as SA335 P11). E91T1-B3 is not suitable for P-15E / Grade 91 (9Cr-1Mo-V). E91T1-B3 deposits must receive PWHT. As-welded hardness of 350–420 HV exceeds the 248 HV code limit. Above 600°C, 2.25Cr-1Mo reaches its creep limit.