AWS Class E81T1-B2 Flux Core
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E81T1-B2 Flux Cored Wire Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier, stockist and importer of E81T1-B2 chrome-moly flux cored wire based in Mumbai, India. We supply E81T1-B2C and E81T1-B2M classifications manufactured to AWS A5.29 / ASME SFA 5.29.
AWS A5.29 E81T1-B2 flux-cored wire provides Cr-Mo chemistry at high deposition rates for heavy-wall pressure equipment fabrication. It deposits about 1.25% Cr and 0.53% Mo. Minimum tensile strength after mandatory PWHT is 80 ksi (550 MPa) with yield at 68 ksi (470 MPa) and elongation of 19%. High-pressure steam piping, refinery reactor loops and boiler superheater systems in 1.25Cr-0.5Mo steel need welds with similar creep strength and hydrogen-attack resistance. Available Diameters of this wire are 0.9, 1.2, 1.4 and 1.6 mm. E81T1-B2C uses 100% CO₂, while B2M runs on 75–80% Ar / 20–25% CO₂. All-position DCEP operation boosts productivity.
Typical applications include oil and gas refining, power generation, petrochemical processing, and pressure vessel fabrication. Every spool ships with EN 10204/3.1 mill test certificates, batch traceability and PMI reports.
E81T1-B2 Flux Core Specifications
The E81T1-B2 specification table lists AWS classification, welding process, shielding gas options, and available spool sizes for this chrome-moly flux cored wire.
| AWS Specification | AWS A5.29/A5.29M:2010 |
|---|---|
| Welding Process | FCAW-G |
| Flux Type | Rutile (Titania-based) |
| Polarity | DCEP |
| Positions | All (F, H, V-Up, OH) |
| Shielding Gas | B2C: 100% CO₂, 35–45 cfh B2M: 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) |
AWS A5.29 Classification Breakdown: What E81T1-B2C and E81T1-B2M Mean
This table explains the AWS A5.29 E81T1-B2 classification, detailing tensile strength, positions, flux-cored construction, chemical composition and recommended shielding gases.
| Designator | Meaning | Specific Detail |
|---|---|---|
| E | Electrode | Indicates a current-carrying filler metal. |
| 8 | Tensile strength | 80 ksi (550 MPa) minimum tensile strength. |
| 1 | Welding Position | All-position capability (flat, overhead, etc.) |
| T | Tubular | Indicates a flux-cored (FCAW) construction |
| 1 | Usability | Rutile slag, DCEP, gas-shielded, multi-pass |
| B2 | Chemical Comp. | 1.25% Cr, 0.5% Mo (matches P-4/Grade 11). |
| C/M | Shielding Gas | C: 100% CO₂; M: 75–80% Ar / Balance CO₂. |
Chemical Composition of E81T1-B2 Weld Deposit (%)
In the E81T1-B2 weld, 1.25% chromium protects against oxidation and sulfidation up to about 550°C, while 0.5% molybdenum strengthens the weld through hardening and stable carbide formation at high temperatures.
| Element | Requirement | Carbon (C) | Manganese (Mn) | Silicon (Si) | Chromium (Cr) | Molybdenum (Mo) | Phosphorus (P) | Sulfur (S) | Nickel (Ni) | Vanadium (V) |
|---|---|---|---|---|---|---|---|---|---|---|
| Element | Requirement | 0.05–0.12 | 1.25 max | 0.80 max | 1.00–1.50 | 0.40–0.65 | 0.03 max | 0.03 max | — | — |
The carbon range of 0.05–0.12% gives a good balance between hardness and toughness. For thin walls (12 mm or less), the B2L low‑carbon grade (C ≤ 0.05%) produces lower hardness after PWHT.
Mechanical Properties of E81T1-B2 Weld Deposit (After PWHT)
Here are the post‑weld heat‑treated mechanical properties of E81T1-B2 weld deposits. The table below shows the tensile strength, yield strength, elongation, and impact values in a simple, easy-to-read format.
| Property | Requirement (PWHT) | Tensile Strength | Yield Strength (0.2%) | Elongation (%) | Charpy V-Notch (−29°C) | Charpy V-Notch (+20°C) |
|---|---|---|---|---|---|---|
| Property | Requirement (PWHT) | 80,000–100,000 psi (550–690 MPa) | ≥68,000 psi (470 MPa) | ≥19% | Not required by AWS for B2 | Not required by AWS for B2 |
AWS A5.29 limits B2 weld metal tensile strength to 100,000 psi (690 MPa) after PWHT. Higher values usually mean the heat treatment was too low or the weld chemistry is incorrect.
Base Metal Compatibility & ASME P-Number Matrix for E81T1-B2
E81T1-B2 is classified under ASME Section IX as F-6 / A-3. The wire matches all P-4 Group 1 and 2 base metals and is also acceptable for P-3 grades where slight chromium overmatching is beneficial.
| Base Metal Specification | Grade | ASME P-No. | Cr-Mo Content | Typical Application |
|---|---|---|---|---|
| SA335 / A335 | P11 | P-4 Grp 1 | 1.25Cr-0.5Mo | Seamless pipe |
| SA335 / A335 | P12 | P-4 Grp 1 | 1.0Cr-0.5Mo | Seamless pipe |
| SA213 / A213 | T11 | P-4 Grp 1 | 1.25Cr-0.5Mo | Boiler/superheater tube |
| SA213 / A213 | T12 | P-4 Grp 1 | 1.0Cr-0.5Mo | Boiler tube |
| SA387 / A387 | Gr 11 Cl.1/2 | P-4 Grp 1/2 | 1.25Cr-0.5Mo | Pressure vessel plate |
| SA387 / A387 | Gr 12 Cl.1/2 | P-4 Grp 1/2 | 1.0Cr-0.5Mo | Pressure vessel plate |
| SA182 / A182 | F11, F12 | P-4 | 1.25Cr / 1.0Cr-0.5Mo | Forged fittings, flanges |
| SA336 / A336 | F11, F11A | P-4 | 1.25Cr-0.5Mo | Forged fittings |
| SA369 / A369 | FP11, FP12 | P-4 | 1.25Cr-0.5Mo | Forged pipe |
| SA335 / A335 | P1 | P-3 Grp 1 | 0.5Mo | Low-Cr piping |
| SA335 / A335 | P2 | P-3 Grp 1 | 0.5Cr-0.5Mo | Low-Cr piping |
Do not use E81T1-B2 wire on P-5A steels such as SA335 P22 or SA213 T22. This combination produces a weld with too little chromium, which is unsafe for long-term high‑temperature service.
Recommended Welding Parameters & Preheat/PWHT Requirements for E81T1-B2 Chrome-Moly Flux Cored Wire
Current ranges below apply to DCEP polarity with 100% CO₂ shielding. For Ar/CO₂ mixed gas, reduce the voltage by 2-5%.
| 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 & Interpass Temperature
| Base Metal Thickness | Minimum Preheat | Maximum Interpass |
|---|---|---|
| ≤12 mm | 150–200°C (300–400°F) | 300°C (572°F) |
| 12–25 mm | 200–250°C (400–480°F) | 300°C (572°F) |
| 25–50 mm | 250–300°C (480–572°F) | 350°C (660°F) |
| >50 mm | 300–350°C (572–660°F) | 350°C (660°F) |
Post-weld heat treatment (PWHT) for E81T1-B2 is mandatory at 680-730°C (1250-1350°F). Hold for at least 1 hour per 25 mm weld thickness. Limit heating to 200°C/hr above 315°C. Limit cooling to 260°C/hr down to 315°C, then air cool as per ASME Section VIII / B31.3. Keep the weld above preheat between passes. Do not exceed 730°C to avoid over-tempering.
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Industrial Applications of E81T1-B2 Flux-Cored Welding Wire
E81T1-B2 flux-cored wire is used with 1.25Cr-0.5Mo steel in high-pressure, high-temperature equipment across six sectors
- Oil & Gas Refining - Hydroprocessing & Reactor Piping: Piping for reactor effluent, the hot-wall hydrodesulphurisation (HDS) unit, the charge heater transfer lines and the hot separator vessels. For SA335 P11 / SA213 T11 piping at 350–550°C in hydrogen service, E81T1-B2 provides matching hydrogen-attack and sulfidation resistance.
- Power Generation - Boiler Superheaters & Steam Piping: Main steam and reheat piping, superheater headers and boiler waterwall tubes (SA213 T11) at 450-540°C and pressures up to 170 bar.
- Petrochemical - Ethylene Cracker & Process Equipment: Transfer line exchangers, pyrolysis furnace outlet piping and process gas boiler parts.
- Pressure Vessel Fabrication - ASME Section VIII: Thick-wall vessels from SA387 Gr 11 plate for hydrogen, catalytic and thermal service. Shell seams, nozzle-to-shell connections and saddle welds.
- Heat Exchanger & Boiler Tube Fabrication: Tube-to-tubesheet welds, header nozzle connections and tube bends for boiler economisers and superheaters using SA213 T11/T12.
- Pipeline & Piping Systems: High-temperature piping per ASME B31.1 and B31.3. E81T1-B2 fills and caps after ER80S-B2 GTAW root pass.
Storage, Handling & Hydrogen Control for E81T1-B2 Flux Cored Wire
Hydrogen control for E81T1-B2 is a safety-critical activity. The hardenable Cr-Mo weld deposit is very likely to crack due to hydrogen. This delayed cracking often causes serious failures in pressure equipment.
- Store sealed spools in dry conditions 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.
- Handle with clean and dry gloves. No contact with carbon steel tooling.
- Packaging must be in vacuum-sealed moisture-barrier bags.
For thick sections (>25 mm), a hydrogen bake-out hold at 250-300°C for 2-4 hours after welding allows trapped hydrogen to diffuse before the microstructure hardens.
How to Order E81T1-B2 from Nicorex Alloys
When ordering E81T1-B2, the following details need to be included.
- Wire / Electrode Type - FCAW wire, AWS A5.29 E81T1-B2
- Size - 1.2 mm / 1.6 mm spool
- Current Type - DCEP, CO₂ or Ar/CO₂ shielding
- Welding Position - Flat, Horizontal, Vertical, Overhead
- Material Grade - Cr-Mo alloy, AWS E81T1-B2
- Quantity - 12.5 kg or 15 kg spools
- Standard - AWS A5.29 / ASME SFA-5.29
- Documentation - EN 10204 3.1 MTC, TPI Report
- Packaging - Spools vacuum foil bag with desiccant
- Delivery Destination - Domestic / International
Nicorex Alloys stocks the complete matching set: E81T1-B2 FCAW + ER80S-B2 GTAW + E8018-B2 SMAW.
Frequently Asked Questions
What is the Price of E81T1-B2 Flux Cored Wire per kg in India?
E81T1-B2 chrome-moly flux-cored wire is more expensive than regular carbon steel FCAW wire (E71T-1) because it has chromium and molybdenum alloys in it. The cost varies based on the size of the spool, the diameter of the wire, the quantity and whether you choose the H4 or B2L version.
What is the difference between E81T1-B2 and E91T1-B3 Chrome-Moly Flux Cored Wires?
E81T1-B2 is for P-4 steels and can be used at temperatures up to 550°C with a minimum tensile strength of 80 ksi. It deposits 1.25Cr-0.5Mo weld metal. E91T1-B3 is for P-5A steels, and it deposits 2.25Cr-1Mo for use at temperatures up to 600°C with a minimum tensile strength of 90 ksi.
Why does E81T1-B2 require a preheat of 200-350°C when Stainless FCAW wires do not?
The Cr-Mo weld metal from E81T1-B2 cools into hard martensite/bainite, a brittle structure that can crack if hydrogen is present. Preheating slows the cooling, lowers hardness and lets hydrogen escape. In contrast, stainless FCAW wires form stable austenite, which does not crack because of oxygen.
Can E81T1-B2 Weld 0.5Cr-0.5Mo (P-3) Base Metals as well as 1.25Cr-0.5Mo (P-4)?
Yes. E81T1-B2 flux-cored wire can weld both 0.5Cr-0.5Mo (P-3) and 1.25Cr-0.5Mo (P-4) steels, including dissimilar joints in Cr-Mo applications.
When not to use E81T1-B2 Flux Cored Wire
Do not use E81T1-B2 for 2.25Cr-1Mo (P-5A) steels like SA335 P22 or SA213 T22. E81T1-B2 is a Cr-Mo low-alloy wire that offers no corrosion resistance in wet service.