E8018-B6 Welding Electrode -Low-Hydrogen SMAW Electrode Supplier
Nicorex Alloys is an ISO 9001 and ISO 14001 certified importer, stockist, and supplier of low-alloy Cr-Mo welding consumables headquartered in Mumbai, India. We carry batch-tested stock of E8018-B6 welding electrodes classified under AWS A5.5 / ASME SFA 5.5, with EN 10204/3.1B mill test certificates on every lot.
Weld metal that resists sulfidation and hydrogen attack is needed for high-sulphur crude refinery pipes at 300°C. E8018-B6 is the code-specified SMAW consumable for this environment. E8018-B6, also known as the 5Cr-0.5Mo welding rod or its old name E502, is a type of welding electrode that has a basic coating. The weld deposit contains approximately 5.0–5.5% Cr and 0.45–0.65% Mo, with carbon at 0.05–0.10%. Mechanical characteristics are measured following post-weld heat treatment per AWS A5. 5. The minimum tensile strength reaches 550 MPa (80 ksi), the yield strength 460 MPa (67 ksi), and the elongation 19%. The UNS designation is W50218.
The 5% Cr content helps prevent rust and damage from sulphur at high temperatures up to 550°C (1022°F), making E8018-B6 the necessary material for ASTM A335 P5, A213 T5, and A387 Grade 5 steel used in FCCU E8018-B6 is available in diameters of 2.5, 3.15, 4.0, 5.0, and 6.3 mm on DCEP or AC, and it works in all locations in sizes as small as 4.0 mm. Industries such as refining, petrochemical processing, electricity generation, and chemical plant manufacturing primarily use it.
E8018-B6 Electrode Specifications & Technical Data
| AWS Classification | E8018-B6 |
|---|---|
| UNS Designation | W50218 |
| ASME SFA / AWS | SFA 5.5 / AWS A5.5 |
| EN ISO Equivalent | EN ISO 3580-A: E CrMo5 B 4 2 H5 |
| Former Classification | E502-16 / E502-18 (AWS A5.4-81, superseded) |
| Welding Process | SMAW (Shielded Metal Arc Welding) |
| Coating Type | Basic low-hydrogen, iron powder (~115–120% recovery) |
| Polarity / Current | DCEP (recommended) or AC |
| Welding Positions | All positions (F, V-up, OH, H) -sizes ≤4.0 mm |
| Available Diameters | 2.5, 3.15, 4.0, 5.0, 6.3 mm |
| F-Number / A-Number | F-4 / A-4 |
| Hydrogen Designation | H4 (≤4 ml/100g) or H8 available |
| Max Service Temperature | 550°C (1022°F) long-term creep |
Understanding the AWS E8018-B6 Stick Electrode Classification
| Designator | Technical Meaning |
|---|---|
| E | Electrode -covered consumable for SMAW |
| 80 | Minimum tensile strength: 80 ksi (550 MPa) after PWHT |
| 1 | All-position welding capability (1G, 2G, 3G, 4G) |
| 8 | Low-hydrogen potassium coating with iron powder; AC and DCEP |
| B6 | Weld deposit: nominal 5% Cr, 0.5% Mo (formerly classified as E502) |
Chemical Composition of E8018-B6 Weld Deposit (%)
| Element | Carbon (C) | Chromium (Cr) | Molybdenum (Mo) | Manganese (Mn) | Silicon (Si) | Nickel (Ni) | Phosphorus (P) | Sulfur (S) |
|---|---|---|---|---|---|---|---|---|
| AWS A5.5 Range (%) | 0.05 – 0.10 | 4.00 – 6.00 | 0.45 – 0.65 | 1.00 max | 0.90 max | 0.40 max | 0.03 max | 0.03 max |
| Typical (%) | 0.06 | 5.20 | 0.50 | 0.90 | 0.40 | — | 0.020 | 0.020 |
Mechanical Properties of E8018-B6 All-Weld-Metal
| Property | Tensile Strength | Yield Strength (0.2%) | Elongation (5d) | Charpy V-Notch (RT) | Creep (1%/10,000 hr, 550°C) |
|---|---|---|---|---|---|
| AWS A5.5 Minimum | ≥550 MPa (80 ksi) | ≥460 MPa (67 ksi) | ≥19% | Not specified | Not specified |
| Typical | 614 MPa (89 ksi) | 505 MPa (73 ksi) | 22% | 60 J | 7 kgf/mm² |
Base Metal Compatibility & P-Number Matrix for E8018-B6
| ASTM Grade | Product Form | P-No. |
|---|---|---|
| A335 P5 | Pipe | P-5B Grp 1 |
| A213 T5 | Boiler/superheater tube | P-5B Grp 1 |
| A182 F5 / F5a | Forged fittings, flanges | P-5B Grp 1 |
| A387 Grade 5 | Plate | P-5B Grp 1 |
| A217 C5 | Castings | P-5B Grp 1 |
Recommended Welding Parameters for E8018-B6
| Diameter (mm) | Length (mm) | Current (A) | Polarity |
|---|---|---|---|
| 2.5 | 350 | 70 – 100 | DC(+) |
| 3.15 | 350 | 100 – 130 | DC(+) |
| 4.0 | 350/450 | 140 – 180 | DC(+) or AC |
| 5.0 | 450 | 180 – 240 | DC(+) or AC |
| 6.3 | 450 | 240 – 300 | DC(+) or AC |
Preheat: 150–260°C (300–500°F) for P5 base metal per ASME B31.3 / API 582.
Interpass max: 300°C. Maintain preheat between passes. After the final pass, slow-cool under insulation or post-heat at 300–350°C for 30 minutes before PWHT.
Get AWS Class E8018-B6 Welding Electrode at Competitive Prices
Industrial Welding Applications of E8018-B6 Electrode
- The pipework includes the FCCU riser and transfer line, crude distillation overhead condensers, and high-sulphur crude service. In sulphur-rich conditions where carbon steel and lower Cr-Mo deteriorate fast, E8018-B6 welds P5 pipe at 400–550°C.
- The HDS and hydrotreating reactor pipes use hydrogen partial pressure. The 5CE8018-B6 electrode makes welds stronger in high-temperature hydrogen situations, where C-0.
- Boiler superheater and reheater tubes undergo welding when steam temperatures exceed 500–550°C. A213 T5 tubes require a matching filler for creep-compatible joints.
- In high-sulphur and sulphurous acid settings, we build heat exchangers and process equipment. Tubesheet-to-shell welds and nozzle attachments are common.
- Refinery turnarounds often require on-site repair of corroded 5Cr piping. SMAW portability and all-position capability (≤4.0 mm dia) make E8018-B6 ideal where GTAW setup is impractical.
Storage, Handling & Re-Drying Procedures for E8018-B6
Sealed cans: Store in dry area, ≥5°C above dew point.
After opening: Transfer to holding oven at 120–175°C (250–350°F).
Re-baking: 370–430°C (700–800°F) for 1 hour if exposed beyond 4 hours. Maximum
3 re-baking cycles; discard if exceeded. Wet electrodes: discard -do not attempt to re-dry.
How to Order E8018-B6 Electrodes from Nicorex Alloys
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AWS Classification - E8018-B6 per AWS A5.5 / ASME SFA 5.5
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Electrode Diameter(s) - Specify in mm (2.5, 3.15, 4.0, 5.0, 6.3)
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Quantity Required - In kg or number of sealed cans
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Packaging Preference - Hermetically sealed cans (2.5 kg or 5.0 kg) or vacuum-packed
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Hydrogen Designation - H4R or H8 (specify if project requires ≤4 ml/100g)
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Third-Party Approvals - Specify whether DNV, ABS, Lloyd's Register, Bureau Veritas, or other certification is needed
-
Test Certificate - Standard MTC 3.1 per EN 10204; provide additional test requirements (CTOD, extra CVN temperatures, Bruscato factor reporting)
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Matching Consumables - Specify if ER80S-B6 TIG wire or MIG wire is also needed for the same project
- Delivery Address & Required Lead Time - Delivery address and required lead time
Frequently Asked Questions
What is the Price of E8018-B6 Welding Electrode per Kg in India?
E8018-B6 pricing varies by diameter, order volume, and required approvals. Contact Nicorex Alloys in Mumbai for current pricing with bulk rates on project orders.
Can E8018-B6 be Used to Weld P5 Pipe to Carbon Steel?
Yes, E8018-B6 is the recommended filler for dissimilar P-5B-to-P-1 joints. The 5Cr deposit, which has 5% chromium, is better than carbon steel at resisting damage from sulphur compounds. Do not use E7018 for this combination.
What is the Minimum Preheat Temperature for Welding with E8018-B6?
150–260°C (300–500°F) for P5 base metal per ASME B31.3 and API 582. Thicker sections (>25 mm) need preheating toward the upper end. Maintain until PWHT begins.
Does Nicorex Alloys Supply Matching TIG Wire for E8018-B6?
Yes, ER80S-B6 (AWS A5.28) is the matching GTAW/GMAW filler. Nicorex supplies matched sets: electrode + TIG rod + MIG wire for chemistry continuity.
Is the E8018-B6 Electrode Suitable for Vertical-Down (PG) Welding?
No, E8018-B6 is designed for vertical-up welding due to its basic coating. Vertical-down causes slag entrapment. For 5Cr downhill pipeline work, use E8015-B6 with sodium-based coating.
When Not to Use E8018-B6 Welding Electrode?
If you need E8018-B8 or E9015-B9, don’t use 9Cr-1Mo (P9) or P91 steel. Avoid using it for ER80S-B6 (GTAW) open-root pipe joints without support. Never weld without PWHT when as-welded hardness exceeds 350 HV, above 241 HB ASME B31.3.