AWS Class ER309L/309H SAW & Flux
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AWS ER309L/309H SAW Wire & Flux Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier and stockist of ER309L and ER309H SAW wire and flux in Mumbai, India. We provide these wires and flux classified under AWS A5.9 / ASME SFA-5.9.
ER309L (UNS S30983) is a stainless steel filler wire with very low carbon (maximum 0.03%), which helps prevent corrosion in dissimilar welds. ER309H (UNS S30980) has slightly higher carbon (0.04-0.08%), giving it better strength at high temperatures above 425°C (800°F). Both ER309L and ER309H are mainly used as transition-layer filler metals for welding austenitic stainless steel to carbon steel or low-alloy steel. These wires have more chromium (23–25%) and nickel (12–14%) than standard grades. The extra alloying offsets dilution when welding to carbon steel. As a result, the final weld metal stays a stable mix of austenite and ferrite instead of turning into hard, brittle martensite. The weld deposit is designed to contain controlled amounts of delta ferrite, which helps prevent hot cracking and improves weld reliability in demanding service conditions.
In submerged arc welding, ER309L/309H wire with flux is the required first layer when applying CRA cladding on carbon steel. It is also the standard filler metal for welding 304 stainless steel to carbon steel. Nicorex supplies ER309L/309H wire together with compatible flux and provides EN 10204-3.1 mill test certificates and full lot traceability with every shipment.
ER309L/309H SAW Wire & Flux Specification
The specifications of ER309L/ 309H SAW wire and flux, including AWS classification, standard and welding process, are listed in the table below:
| AWS Classification | ER309L | ER309H |
|---|---|
| Standard | AWS A5.9 / ASME SFA 5.9 |
| UNS | S30983 | S30980 |
| Welding Process | SAW (Submerged Arc Welding) |
| Form | Solid bare wire (continuous electrode for SAW) |
What Does ER309L/309H Mean? — AWS A5.9 Classification Explained
ER309L/ 309H is explained along with its designation and the meaning of each element in the table given below:
| Prefix/Suffix | ER309L | ER309H | Meaning |
|---|---|---|---|
| E | E | E | Electrode (filler metal for arc welding) |
| R | R | R | Rod (also usable as GTAW rod) |
| 309 | 309 | 309 | Type 309 SS (23Cr-12Ni) |
| L / H | L | H | Low C (≤0.03%) / High C (0.04-0.08%) |
“309” denotes 23Cr-12Ni; richer than “308” (19.5Cr-9Ni). That over-alloying compensates for dilution from carbon steel. “L” restricts carbon to prevent sensitisation; “H” controls it at 0.04-0.08% for creep strength. L and H are mutually exclusive.
Chemical Composition of ER309L and ER309H (AWS A5.9)
The chemical composition of ER309L/ 309H, along with its proportion in percentage, is listed in the table below:
| Material / Element | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Manganese (Mn) | Silicon (Si) | Molybdenum (Mo) | Copper (Cu) | Phosphorus (P) | Sulphur (S) |
|---|---|---|---|---|---|---|---|---|---|
| ER309L (wt%) | 0.03 max | 23.0-25.0 | 12.0-14.0 | 1.0-2.5 | 0.30-0.65 | 0.75 max | 0.75 max | 0.03 max | 0.03 max |
| ER309H (wt%) | 0.04-0.08 | 23.0-25.0 | 12.0-14.0 | 1.0-2.5 | 0.30-0.65 | 0.75 max | 0.75 max | 0.03 max | 0.03 max |
Carbon is the only difference between L and H. Cr at 23-25% is 3-4% higher than ER308L, Ni at 12-14% about 3% higher. At 30% dilution with carbon steel, the deposit retains roughly 16-17.5% Cr and 8.5-10% Ni; safely austenitic-ferritic. Mo at 0.75% max is residual; for 316L dissimilar joints, use ER309LMo (UNS S30986). Heat-specific values are confirmed on the EN 10204-3.1 MTC.
Mechanical Properties of ER309L/309H Weld Deposit
The mechanical properties of ER309L/ 309H weld deposit, including tensile strength, elongation and yield strength, are listed below:
| Property | Ultimate Tensile Strength | Yield Strength (0.2%) | Elongation | Hardness |
|---|---|---|---|---|
| ER309L (Typical) | 75-95 ksi (515-655 MPa) | 45-70 ksi (310-483 MPa) | 30-40% | ~80-92 HRB |
| ER309H (Typical) | 80-100 ksi (550-690 MPa) | 50-75 ksi (345-517 MPa) | 25-35% | ~85-95 HRB |
ER309H shows higher room-temperature strength due to higher carbon, but its primary advantage is creep-rupture performance above 425°C. In dissimilar joints, 20-40% dilution alters actual properties.
Base Metals Compatible with ER309L/309H SAW Wire
The base metal and its compatibility, along with the grade and ASME number, are listed in the table below:
| Base Metal Combination | Grade (Filler) | ASME No. (P-No.) | Notes |
|---|---|---|---|
| 304/304L to Carbon Steel | ER309L | P-8 to P-1 | General dissimilar joints (SA516 Gr.70, A36) |
| 304H to CS / Cr-Mo Steel | ER309H | P-8 to P-1 / P-4 / P-5 | Suitable for elevated-temperature service |
| 304/304L to Low-Alloy Steel | ER309L | P-8 to P-4 / P-5 | Used for SA387 Gr.11/22 transitions |
| 321 / 347 to Carbon Steel | ER309L | P-8 to P-1 | Stabilised stainless to CS joints |
| Austenitic SS to Ferritic SS | ER309L | P-8 to P-6 | Applicable for 409, 410S combinations |
| CS with 304/304L Cladding | ER309L / ER308L | P-1 + P-8 | Buffer + fill pass sequence |
| CS with 304H Cladding | ER309H / ER308H | P-1 + P-8 | High-temperature clad applications |
ER309L serves primarily as a transition filler for dissimilar welding, not for matching compositions. Use ER308L to weld 304 stainless steel to 304 stainless steel. ER309LMo is used to weld 316L stainless steel to carbon steel, so the weld stays corrosion-resistant and avoids problems from dilution.
Recommended SAW Welding Parameters for ER309L/309H
The table below explains typical SAW welding parameters for ER309L and ER309H, based on wire diameter and welding application.
SAW Welding Parameters (ER309L / ER309H)
| Diameter | Ampere (A) | Voltage (V) | Position |
|---|---|---|---|
| 2.4 mm | 300–450 | 28–32 | Cladding |
| 3.2 mm | 400–550 | 30–34 | Butt joints |
Heat input control is critical in ER309L cladding, as it directly affects dilution and overlay chemistry. Lower heat input minimises dilution, while higher input increases it. Preheat and PWHT depend on the ferritic side requirements, and final procedures must be qualified per applicable welding standards.
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Industries and Applications of ER309L/309H SAW Wire & Flux
ER309L and ER309H appear wherever clad vessels or stainless-to-carbon-steel joints are fabricated.
- Oil & gas/petrochemical: mandatory first layer under ER308L or ER316L overlay on CS vessels.
- Chemical processing: 304L-to-CS transitions.
- Power generation: ER309H for 304H-to-P22/P91 superheater transitions.
- Pulp & paper: 304L-clad digesters.
- Food & Beverage / Pharmaceutical: Used for large stainless-lined carbon steel vessels and tanks
- Shipbuilding and Marine: Used for stainless-lined carbon steel (CS) structures in ships and offshore equipment.
- Water treatment: Used in clarifiers, mixing tanks, and pipe fittings to connect stainless steel parts to carbon steel systems.
- Fertiliser & Urea: Used as a buffer layer for cladding high-pressure urea reactor linings and carbamate condensers, with ER309LMo or special urea-grade consumables.
Storage and Handling of ER309L/309H SAW Wire & Flux
Store flux in sealed containers at below 50% relative humidity. If exposed beyond the allowed window, rebake per manufacturer instructions (typically 250-350°C for 1-2 hours). Recycled unfused flux may be blended at a maximum 50% ratio. Store wire in original packaging, free from oil, grease, and condensation. Keep stainless SAW wire separate from carbon steel consumables to prevent iron contamination.
ER309L/309H SAW Wire Sizes & Packaging
Nicorex Alloys supply ER309L/ 309H SAW Wire and Flux in the following forms, diameters and packaging options:
| Form | Diameter | Packaging |
|---|---|---|
| SAW Wire | 2.0 mm (5/64″) | Coils: 12.5 kg, 25 kg |
| SAW Wire | 2.4 mm (3/32″) | Coils: 12.5 kg, 25 kg |
| SAW Wire | 3.2 mm (1/8″) | Drums: 100 kg, 250 kg |
| SAW Wire | 4.0 mm (5/32″) | Drums: 100 kg, 250 kg |
Both variants are available across all diameters. Specify L or H at order. All packaging carries lot ID labels, EN 10204-3.1 MTC, and sealed moisture protection.
How to Order AWS Class ER309L/309H SAW Wire & Flux from Nicorex Alloys
To order ER309L/ 309H SAW wire & flux from Nicorex Alloys, provide these 10 important details:
- AWS Classification & UNS: ER309L (S30983) or ER309H (S30980)
- Product Form: SAW wire, flux, or wire + flux combination
- Wire Diameter: 2.0, 2.4, 3.2, or 4.0 mm
- Flux Type & Grade: specify or request Nicorex recommendation
- Packaging: coil or drum, weight
- Standard: AWS A5.9 / ASME SFA-5.9 or project specification
- Base Metal Application: e.g., 304L-to-CS joint, CRA cladding on SA516-70
- Quantity: kg or number of packages
- Documentation: EN 10204-3.1 MTC, CoC, SDS
- Delivery Destination: Domestic
Frequently Asked Questions
Why is ER309L used instead of ER308L for Welding Stainless Steel to Carbon Steel?
ER309L has higher Cr (23-25%) and Ni (12-14%) than ER308L. That over-alloyed chemistry keeps the diluted deposit austenitic-ferritic. ER308L on carbon steel risks Cr/Ni depletion and martensite at the fusion line.
What is the difference between ER309L and ER309H?
ER309L and ER309H differ only in carbon. ER309L (≤0.03%) is for corrosion resistance; ER309H (0.04–0.08%) is for high-temperature strength above 425°C.
Can ER309L be used for the entire stainless cladding thickness on Carbon Steel?
It is not a standard practice. The accepted approach is ER309L for the first buffer layer, then ER308L for fill layers. Full-thickness 309L increases cost and raises ferrite levels.
What is the difference between ER309L and ER309LMo?
ER309LMo (UNS S30986) contains 2-3% Mo. It bridges to 316/316L. Using ER309L (no Mo) creates a Mo-free zone prone to preferential corrosion.
What dilution level is acceptable for ER309L SAW Cladding on carbon steel?
Up to 30-40% dilution is manageable for ER309L SAW cladding on carbon steel. Above ~40%, martensite risk rises. Control dilution through SAW parameters and flux selection; WPS must verify first-layer chemistry.
Does ER309L/309H SAW require preheat?
Preheat is not required for the stainless steel side. If the carbon steel or Cr-Mo base requires preheat per its WPS, apply it to the ferritic side only.
Can ER309L be used to join two pieces of 304 stainless steel?
It produces a sound joint, but ER308L is the correct filler for 304-to-304. ER309L’s higher alloy content produces unnecessary ferrite that can reduce toughness.