AWS Class ER90S-B9 MIG & TIG
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ER90S-B9 TIG Filler Rod & MIG Wire Supplier in India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified Mumbai-based supplier and stockist of ER90S-B9 welding wire for P91 (9Cr-1Mo-V-Nb modified) steel. We provide these wires classified under AWS A5.28 / ASME SFA-5.28.
ER90S-B9 is a solid wire alloyed with 9% Cr, 1% Mo and modified with vanadium (0.15–0.30%), niobium (0.02–0.10%), and nitrogen (0.02–0.07%). These micro-alloying additions form stable MX-type carbonitrides, (V, Nb)(C, N), that give the weld deposit far greater creep rupture life. After the required PWHT at 730–770 °C, the weld metal forms a tempered martensite structure and achieves a minimum tensile strength of 620 MPa (90 ksi). The chemistry is tightly controlled compared to other CrMo fillers. Phosphorus (P) and sulphur (S) are each limited to a maximum of 0.010%, and the combined manganese plus nickel (Mn+Ni) must not exceed 1.50% to avoid delta-ferrite in the weld. Before starting PWHT, the weld joint must be allowed to cool below 100 °C so that the martensite transformation can fully finish. TIG filler rods are available in diameters from 1.6 to 3.2 mm, and MIG wire is supplied in 0.9 and 1.2 mm diameters.
ER90S-B9 serves ultra-supercritical and supercritical power plants, HRSG superheater tubes, petrochemical high-temperature reactors, and turbine casings where service temperatures reach 620 °C (1150 °F). All shipments from Nicorex Alloys carry EN 10204/3.1 mill test certificates with full V, Nb, N, and Mn+Ni reporting.
ER90S-B9 Welding Wire Specifications
The specifications of ER90S-B9 welding wire, along with its AWS classification, shielding gas and polarity, are mentioned in the table:
| AWS Classification | A5.28 ER90S-B9 |
|---|---|
| Welding Processes | GTAW, GMAW, SAW |
| Polarity | (GTAW): DCEN (GMAW): DCEP |
| Welding Positions | All positions |
| Shielding Gas | (GTAW): 100% Argon (GMAW): 98Ar/2O₂ or Ar/He/CO₂ blends |
| TIG Rod Diameters | 1.6, 2.0, 2.4, 3.2 mm |
| MIG Wire Diameters | 0.9, 1.2 mm |
AWS Classification Explained: What Does ER90S-B9 Mean?
The AWS Classification of ER90S-B9, along with its designation and meaning, is explained in the table below:
| Designation | Meaning |
|---|---|
| ER | Electrode / Rod (solid filler for GTAW and GMAW) |
| 90 | 90 ksi (620 MPa) minimum tensile strength after PWHT |
| S | Solid wire cross-section |
| B9 | 9Cr-1Mo-V-Nb modified alloy group (P91 type) |
Chemical Composition of ER90S-B9 Weld Deposit
The chemical composition of the ER90S-B9 weld deposit proportion in percentage is listed in the table below:
| Specification | Carbon (C) | Manganese (Mn) | Silicon (Si) | Chromium (Cr) | Molybdenum (Mo) | Vanadium (V) | Niobium (Nb) | Nitrogen (N) | Nickel (Ni) | Phosphorus (P) | Sulphur (S) | Copper (Cu) | Mn + Ni |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AWS A5.28 Range (%) | 0.07–0.13 | 1.20 max | 0.15–0.50 | 8.00–10.50 | 0.85–1.20 | 0.15–0.30 | 0.02–0.10 | 0.02–0.07 | 0.80 max | 0.010 max | 0.010 max | 0.25 max | ≤ 1.50 |
All-Weld-Metal Mechanical Properties of ER90S-B9
The mechanical properties of ER90S-B9, along with its tensile strength, yield strength and elongation, are listed in the table below:
| Specification | Tensile Strength | Yield Strength (0.2% Offset) | Elongation | Charpy V-Notch (+20°C) |
|---|---|---|---|---|
| AWS A5.28 Minimum (PWHT) | 620 MPa (90 ksi) | 415 MPa (60 ksi) | 17% | Not specified by AWS |
| Typical (PWHT ~760°C) | 760 MPa (110 ksi) | 640 MPa (93 ksi) | 19% | 47–80 J typical |
Base Metal Compatibility and ASME Section IX Data for ER90S-B9
The base metal and its compatibility are listed below in the table, along with grade and product form:
| Base Metal | P-No. | Grade | Product Form |
|---|---|---|---|
| SA-335 | P-No. 5B | P91 | Seamless Pipe |
| SA-213 | P-No. 5B | T91 | Seamless Tube |
| SA-182 | P-No. 5B | F91 | Forgings |
| SA-217 | P-No. 5B | C12A | Castings |
| SA-387 | P-No. 5B | Gr.91 Cl.2 | Plate |
Dissimilar Joint Guidance:
| Base Metal Combination | P-No. Combination | Recommended Filler | Notes |
|---|---|---|---|
| P91 to P22 (2.25Cr-1Mo) | P-5B to P-5A | ER90S-B9 or ER90S-B3 | B9 on P91 side; B3 or ERNiCr-3 at interface |
| P91 to Carbon Steel | P-5B to P-1 | ERNiCr-3 (Inconel 82) | Avoids carbon migration and hardness concerns |
| P91 to Austenitic Stainless Steel | P-5B to P-8 | ERNiCr-3 or ERNiCrMo-3 | Never use ER90S-B9 against stainless steel |
Recommended Welding Parameters for ER90S-B9 TIG & MIG Wire
GTAW (TIG) on DCEN is the preferred process for P91 root passes.
| Wire Diameter | Amperage (A) | Voltage (V) | Shielding Gas |
|---|---|---|---|
| 1.6 mm (1/16″) | 60–110 | 10–14 | 100% Argon |
| 2.0 mm (5/64″) | 80–140 | 11–15 | 100% Argon |
| 2.4 mm (3/32″) | 100–180 | 12–16 | 100% Argon |
| 3.2 mm (1/8″) | 140–220 | 14–18 | 100% Argon |
GMAW parameters: 0.9 mm wire at 100–180 A; 1.2 mm wire at 150–250 A with 98Ar/2O₂ or Ar/He/CO₂ blends. Low heat input with stringer beads reduces delta-ferrite and hydrogen cracking risk. Preheat at 200–300 °C and hold interpass within the same range. After welding, hold at 200–250 °C for a minimum of 2 hours hydrogen bake-out, then cool to 80–100 °C before starting PWHT. Post-PWHT hardness should fall between 200 and 270 HV. Heat and cool at 50–100 °C/hr above 300 °C.
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Industrial Applications of ER90S-B9 (P91) Filler Wire
ER90S-B9 filler wire is used to withstand tough operating conditions in the following high-performance industries:
- Ultra-supercritical (USC) and Supercritical (SC) Coal-Fired Power Plants: P91 with ER90S-B9 is used for main steam and hot reheat piping (SA-335 P91).
- Combined Cycle Gas Turbine (CCGT) Plants: In HRSG units of CCGT plants, P91/ER90S-B9 is applied for superheater tubes.
- Conventional Power Plants: Used in high-temperature piping circuits.
- Petrochemical: ER90S-B9 is used to weld P91 components in high-temperature petrochemical reactors.
- Turbine Components: P91/ER90S-B9 is selected for turbine casings and valve bodies (SA-182 F91).
- P91 to P22 Dissimilar Joints: ER90S-B9 serves as the matching filler on the P91 side for dissimilar welds to P22.
Storage and Handling of ER90S-B9
ER90S-B9 demands the strictest low-hydrogen practice of any CrMo filler. The as-welded deposit is fully martensitic and susceptible to hydrogen-induced cracking. Store wire in sealed packaging below 40% relative humidity. Most ER90S-B9 is supplied copper-free; do not mix with copper-coated spools. For the matching electrode E9018-B9, maintain rod ovens at 120–150 °C and re-bake at 370 °C for 2 hours (one re-bake maximum).
Available Forms and Packaging of ER90S-B9 Welding Filler Metal
Nicorex Alloys stocks ER90S-B9 in the forms, diameters and packaging mentioned in the table below:
| Form | Diameter | Packaging |
|---|---|---|
| TIG Rod | 1.6, 2.0, 2.4, 3.2 mm | 5 kg sealed tubes, 914/1000 mm length |
| MIG Spool (copper-free) | 0.9, 1.2 mm | D200 / D300 spools |
| SAW Wire (EB9) | 2.4, 3.2 mm | 25 kg coils |
How to Order ER90S-B9 MIG & TIG from Nicorex Alloys
To order ER90S-B9 TIG filler rod & MIG wire, provide these 9 important details:
- Wire Type — GTAW (TIG) / GMAW (MIG) Solid Wire for 9Cr-1Mo-V-Nb Creep-Resistant Steel (ER90S-B9)
- Size — 0.9mm / 1.2mm (GMAW spools) / 1.6mm / 2.4mm / 3.2mm (GTAW cut lengths)
- Current Type — DCEN (GTAW) / DCEP (GMAW)
- Welding Position — All Positions
- Material Grade — 9Cr-1Mo-V-Nb Low Alloy Steel Wire / AWS A5.28 / ASME SFA 5.28: ER90S-B9
- Quantity — Number of spools/packs or total weight in kg
- Standard — AWS A5.28 / ASME SFA 5.28, EN ISO 21952-A: G CrMo91, ASME Section IX
- Documentation — MTC 3.1/3.2, PMI Report, Weld Metal Composition Report, Mechanical Properties Report (PWHT condition), TPI Certificate
- Delivery — Domestic
Frequently Asked Questions
What is Delta Ferrite in P91 Weld Metal, and why is it harmful?
When the Cr equivalent (ferrite-promoting) exceeds the Ni equivalent (austenite-promoting), delta ferrite persists in the solidified microstructure. It has much lower creep strength than tempered martensite, provides preferential cavity nucleation sites, and reduces impact toughness. Chemistry must be balanced for a fully martensitic deposit.
What is the difference between ER90S-B9 and ER90S-B91?
ER90S-B9 is the standard P91 filler; ER90S-B91 is a tighter-spec variant with narrower Si and trace limits. Both weld P91/T91/F91, but B91 enhances microstructural control.
What Spool Sizes are available for ER90S-B9?
TIG rods are available in 914/1000 mm lengths, 5 kg sealed tubes. MIG spools in D200 and D300 sizes. SAW coils at 25 kg. Every lot ships with an EN 10204/3.1 MTC covering full chemistry, including V, Nb, N, the Mn+Ni sum, and X-Factor.
When should ER90S-B9 not be used?
Do not use ER90S-B9 for conventional 9Cr-1Mo base metals (P9/T9). Do not use it for 2.25Cr-1Mo steel (use ER90S-B3). Never apply PWHT without first cooling 100 °C below. Never weld P91 without PWHT. Do not exceed the project-specified Mn+Ni limit.