AWS Class E308HT1-1/T1-4 Flux Core
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E308HT1-1/T1-4 Flux Core Wire Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier and stockist of E308HT1-1/T1-4 Flux Core Wire, based in Mumbai, India. We provide these wires classified under AWS A5.22 / ASME SFA 5.22 (UNS W30831), which is a gas-shielded, all-position, rutile-type flux-cored electrode.
The typical weld deposit chemistry of E308HT1 is about Cr 19%, Ni 9.5-10%, C 0.04-0.08%, and Mn 1.2-1.7%. Standard low-carbon 308L welds lose creep strength above 400°C, which is a severe issue for reformer tubes, superheater headers, and reactor vessels. To address this, we supply internationally certified 308H flux-cored (FCAW) wire for Indian fabricators and EPC contractors. The key ‘H’ feature is its higher carbon content of 0.04-0.08%, which gives better creep strength above 399°C (750°F). Ferrite is kept between 3 and 9 FN to prevent cracks while still giving dependable performance at high temperatures. According to AWS A5.22, the weld metal must have at least 80 ksi (550 MPa) tensile strength, 58 ksi (400 MPa) yield strength, and 35% elongation. With an Ar/CO₂ shielding gas mix, typical results are 87-93 ksi tensile strength and 40-47% elongation.
Supplied in 1.2 mm, 1.4 mm, and 1.6 mm diameters, the wire is vacuum-packed on D200/D300 spools in 5 kg, 12.5 kg, and 15 kg sizes. It is designed for AISI 304H (UNS S30409), 304, 302, 321, and 347 base metals, all P-No. 8, Group 1. Key industries are the petrochemical, power, and chemical industries, with each batch supplied with EN 10204 3.1 MTC and test reports.
E308HT1-1/T1-4 Flux Core Wire Technical Specifications
The technical specifications of E308HT1-1/T1-4 flux-cored wire, covering classification, welding parameters, and packaging, are listed below.
| UNS Number | W30831 |
|---|---|
| Welding Process | FCAW-G (Gas-Shielded Flux-Cored Arc Welding) |
| Polarity | DCEP (Direct Current Electrode Positive) |
| Welding Positions | All positions: Flat, Horizontal, Vertical-Up, Overhead |
| Shielding Gas | T1-1: 100% CO₂ (C1) • T1-4: 75-80% Ar / bal CO₂ (M21); 12-20 L/min (25-40 cfh) |
| Available Diameters | 1.2 mm (0.047″), 1.4 mm (0.052″), 1.6 mm (1/16″) |
AWS Classification of E308HT1-1/T1-4 Flux Core
The breakdown of each character in the E308HT1-1/T1-4 designation presents a specific meaning in tabular form below.
| Designator | Meaning |
|---|---|
| E | Electrode: flux-cored, current-carrying electrode for arc welding. |
| 308H | Deposit: 18%Cr-9%Ni austenitic stainless; higher C (0.04-0.08%) than 308L (≤0.04%) for better creep strength above 399°C (750°F). |
| T | Tubular, flux-cored wire (not ER solid, not covered rod). |
| 1 (before dash) | All-position use: flat, horizontal, vertical-up, overhead. |
| -1 | Tested with 100% CO₂ shielding gas. |
| /T1-4 | Also qualified with 75-80% Ar/balance CO₂ (M21/C25). |
In full, E308HT1-1/T1-4 designates a gas-shielded, all-position, rutile-type flux-cored electrode depositing a high-carbon 18Cr-9Ni weld metal per AWS A5.22. The dual gas classification (T1-1/T1-4) gives shops flexibility to qualify under either CO₂ or Ar/CO₂ without changing the filler metal.
Weld Deposit Chemical Composition — per AWS A5.22
The chemical composition requirements for E308HT1-1/T1-4 along with its proportion, are specified in the table below.
| Element | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) | Molybdenum (Mo) | Copper (Cu) |
|---|---|---|---|---|---|---|---|---|---|
| AWS A5.22 Requirement (wt%) | 0.04 – 0.08 | 19.0 – 21.0 | 9.0 – 11.0 | 0.5 – 2.5 | 1.0 max | 0.04 max | 0.03 max | 0.75 max | 0.75 max |
| Typical Deposit (wt%) [Ar/CO₂] | 0.05 – 0.07 | 19.0 – 20.5 | 9.5 – 10.5 | 1.2 – 1.7 | 0.5 – 0.8 | ≤ 0.025 | ≤ 0.018 | ≤ 0.3 | ≤ 0.15 |
The 0.04-0.08% C range is the key differentiator from E308LT1-1 (≤0.04% C), trading sensitisation resistance for elevated-temperature creep strength. Typical as-welded FN falls in the 3-9 range per the WRC-1992 diagram. With 100% CO₂, carbon trends toward the upper limit; an Ar/CO₂ mix gives a more consistent mid-range deposit.
All-Weld-Metal Mechanical Properties — E308HT1-1/T1-4
The mechanical properties of E308HT1-1/T1-4 Flux Core Wire, including tensile strength, elongation and tensile strength, are listed in the table below.
| Property | Tensile Strength | Yield Strength (0.2%) | Elongation (50 mm) | Charpy V-Notch Impact | Ferrite Number (FN) | Hardness |
|---|---|---|---|---|---|---|
| AWS A5.22 Minimum | 80 ksi (550 MPa) | 58 ksi (400 MPa) | 35% minimum | Not required* | Not specified | Not specified |
| Typical (Ar/CO₂, As-Welded) | 87-93 ksi (600-640 MPa) | 65-72 ksi (450-495 MPa) | 40-47% | Not specified | 3-9 FN typical (WRC-1992) | ~HRB 85-92 (informational) |
*AWS A5.22 does not mandate a Charpy impact test for 308H-type stainless FCAW. If sub-zero toughness is required, specify E308LT1-1/T1-4 for cryogenic service. For service above 550°C long-term, restrict FN to 3-5 to limit sigma-phase risk.
Base Metal Compatibility of AWS Class E308HT1-1/T1-4 Flux Core
Per ASME IX, E308HT1-1/T1-4 (F-6, A-8) qualifies WPSs for all P-8 base metals, subject to essential variables.
Similar Metal Joints (P-8 to P-8)
| AISI Type | UNS | P-No. / Group | Notes |
|---|---|---|---|
| 304H | S30409 | P-8 Group 1 | Primary base metal for this consumable |
| 304 | S30400 | P-8 Group 1 | Use 308H for service above 399°C |
| 302 | S30200 | P-8 Group 1 | Less common; verify service temperature |
| 308/308H | S30800/S30809 | P-8 Group 1 | Matching composition weld |
| 321/321H | S32100/S32109 | P-8 Group 1 | Use 308H above 399°C for improved ductility vs ER347 |
| 347/347H | S34700/S34709 | P-8 Group 1 | Use 308H above 750°F for better ductility — verify project spec |
E308HT1-1 is not preferred for dissimilar joints between P-8 stainless and P-1/P-3/P-4/P-5 steels. For P-1 to P-8 joints, use E309LT1-1/T1-4. For P-8 to P-5A high-temperature dissimilar joints, consider ENiCrFe-3.
E308HT1-1/T1-4 Flux Core Wire Welding Parameters
Parameters below are guidelines from AWS A5.22 and manufacturer datasheets. Always verify against the qualified WPS.
| Parameter | 1.2 mm (0.047″) | 1.6 mm (1/16″) |
|---|---|---|
| Current — Flat/Horizontal | 100-200 A | 150-280 A |
| Current — Vertical-Up | 100-160 A | 140-200 A |
| Current — Overhead | 100-160 A | 140-190 A |
| Arc Voltage (flat) | 22-26 V | 24-30 V |
| Arc Voltage (positional) | 20-24 V | 22-26 V |
| Polarity | DCEP | DCEP |
| Wire Feed Speed | 3.5-7.5 m/min | 2.5-6.0 m/min |
| Electrode Extension (CTWD) | 16-20 mm | 18-22 mm |
| Shielding Gas Flow | 12-16 L/min | 14-20 L/min |
| Travel Speed | 250-450 mm/min | 200-380 mm/min |
Preheat is not normally required for P-8 base metals. On sections exceeding 25 mm, light preheating to 100°C may reduce hydrogen cracking risk. Maximum interpass temperature is 150°C (302°F): exceeding this increases ferrite in successive passes and accelerates sigma-phase formation during elevated-temperature service.
PWHT is not recommended for E308HT1-1/T1-4 deposits. Solution annealing at 1050-1100°C plus water quench is the only viable treatment, and is generally impractical for fabricated assemblies. Never apply carbon steel PWHT temperatures (600-700°C) to 308H deposits: these sit in the sensitisation and sigma embrittlement range.
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Industrial Welding Applications of E308HT1-1/T1-4 Flux Core Wire
E308HT1-1/T1-4 serves 4 industry sectors where 304H components operate above 399°C and require high deposition-rate FCAW with a creep-resistant deposit.
- Petrochemical and Refinery Fabrication: Cat crackers, reformer headers, pigtails, and FCC unit components.
- Power Generation: Supercritical boiler 304H headers (550-620°C, 250-280 bar) need creep-resistant welds with controlled ferrite, and E308HT1-1 FCAW gives faster production than GTAW on heavy-wall butt and nozzle-to-header welds under ASME Section I.
- Chemical Processing: For 304H vessels in sulfuric and acetic acid units and high-temperature organic reactors, E308HT1-1/T1-4 enables high-deposition, all-position multi-pass seams and nozzle welds up to ~650°C; above this, consider ERNiCrMo-3 or ER310.
- Pulp and Paper: In kraft pulp mills, 304H recovery boilers and digesters use E308HT1-1 FCAW for efficient welding of heavy sections with creep-resistant deposits.
Storage, Handling and Moisture Control
E308HT1-1/T1-4 is not classified as a low-hydrogen electrode, but moisture in the flux core still causes porosity and hydrogen pickup.
- Storage Conditions: Store spools in their original vacuum-sealed packaging in a clean, dry room at 15-30°C with RH ≤55%. This is especially important in Mumbai and coastal shops during the monsoon.
- Opened Spool Handling: After opening, keep spools in a humidity-controlled cabinet or sealed bag with desiccant. Use within 7-14 days above 70% RH or up to 30 days below 55% RH, and never leave the wire on the feeder uncovered overnight.
- Re-Drying (If Required): Re-drying (only if needed): If you see rust-like discolouration on the wire or get porous welds, gently re-dry the wire at 150–250°C for 1–2 hours. AWS A5.22 does not require a full re-bake, and overheating can damage the flux core, so always follow the temperature limits in the manufacturer’s datasheet.
- Packaging: Spools are vacuum-sealed in bags and packed in cardboard cartons in 5 kg (D200), 12.5 kg, and 15 kg (D300/BS300) sizes. Sealed shelf life is 24 months under proper storage conditions.
How to Order E308HT1-1/T1-4 Flux Core Wire from Nicorex Alloys
To receive an accurate quotation with MTC 3.1 documentation, include these details in your RFQ.
- AWS Classification - E308HT1-1/T1-4 per AWS A5.22 / ASME SFA 5.22
- Diameter - 1.2 mm or 1.6 mm
- Quantity - In kg (e.g., 100 kg / 500 kg)
- Spool Type & Weight - D300 15 kg spool
- Shielding Gas - 100% CO₂ (T1-1) or 75% Ar / 25% CO₂ (T1-4)
- Required Approvals - None / ABS / DNV / BV / LR
- Certificate Requirements - MTC 3.1 per EN 10204 + COC per AWS A5.22
- Project / Application - e.g., 304H pressure vessel, FCAW positional
- Delivery Address - City, State, Country
Nicorex Alloys also supplies matching consumables: ER308H TIG rods and E308H-16 SMAW electrodes, enabling single-source procurement for all 308H welding procedure qualifications.
Frequently Asked Questions
What is the price of E308HT1-1/T1-4 Flux-Cored Wire per kg in India?
Pricing depends on diameter, spool size, quantity, origin, and approvals (DNV, ABS, BV) and follows LME nickel/chromium, so contact Nicorex Alloys with specification and delivery details for a current MTC 3.1-based quote.
What is the difference between E308HT1-1/T1-4 and E308LT1-1/T1-4 for Welding 304H Stainless Steel?
E308HT1-1 has a higher carbon content (0.04–0.08%), which gives better creep strength at temperatures above 399°C. E308LT1-1 has lower carbon (0.04% or less), which improves resistance to intergranular corrosion and is the better choice for use below 399°C.
What is the F-Number and A-Number for E308HT1-1/T1-4 per ASME Section IX?
E308HT1-1/T1-4 is classified as F-Number 6 and A-Number 8. This means it can be used to qualify any SFA-5.22 electrode that is also F-6 and A-8 under ASME Section IX rules.
Why is Ferrite Number (FN) critical for E308HT1-1/T1-4 welds in High-Temperature Service?
FN is controlled to about 3-9 to avoid solidification cracking yet limit sigma-phase embrittlement above ~550-600°C, with FN often verified by ferritescope and recorded on the MTC.
Can E308HT1-1/T1-4 be used to weld type 321 and 347H Stainless Steels?
It is suitable for 321/347H above 399°C, where higher ductility than ER347 is needed, but a matching stabilised filler may be mandatory by code or project spec.
What Shielding Gas should I use with E308HT1-1/T1-4 — 100% CO₂ or Ar/CO₂ Mix?
Both are code-qualified; Ar/CO₂ gives a smoother arc, lower spatter, and slightly higher strength, while 100% CO₂ is cheaper with deeper penetration for heavy or outdoor work.
Does Nicorex Alloys supply E308HT1-1/T1-4 with DNV or ABS Approval?
Nicorex Alloys can supply lot-specific DNV, ABS, BV, or LR-approved wire, provided the required body is specified in the RFQ.
What is the maximum continuous service temperature for E308HT1-1/T1-4 weld Deposits?
E308HT1-1/T1-4 welds are typically suitable up to about 650°C, above which sigma embrittlement and creep increase and alternatives like ER310 or ERNiCrMo-3 should be considered, with FN held to about 3-5 above 550°C.