Lincoln Excalibur 9018-B3 MR E9018-B3 — Overview
Lincoln Excalibur 9018-B3 MR is a low-alloy, low-hydrogen SMAW electrode classified to AWS A5.5/A5.5M E9018-B3, designed for welding 2¼Cr-1Mo (P22) creep-resistant alloy steel in high-temperature pressure vessel, refinery, and power generation applications. The B3 chemistry deposit contains nominally 2.25% chromium and 1% molybdenum to match the creep strength and thermal fatigue resistance of the base metal. The MR designation (Moisture Resistant) indicates a hermetically sealed package that maintains the low-hydrogen condition of the coating during storage — critical for avoiding hydrogen-induced cracking in high-strength alloy steels. DC+ (DCEP) only; all positions. Available through WeldingMart as an authorized Lincoln Electric distributor.
Specifications
| AWS classification | AWS A5.5/A5.5M E9018-B3 |
|---|---|
| Alloy chemistry (deposit) | 2.25% Cr, 1.0% Mo (nominal) |
| Coating type | Low-hydrogen, iron-powder basic |
| Polarity | DC+ (DCEP) only |
| Welding positions | All positions: 1G, 2G, 3G, 4G |
| Minimum tensile strength | 90,000 psi (620 MPa) |
| Minimum yield strength | 78,000 psi (538 MPa) |
| Elongation | 14% minimum |
| Moisture Resistant (MR) | Yes — hermetically sealed packaging |
| Typical current range | 1/8 in: 90–140 A | 5/32 in: 120–175 A | 3/16 in: 150–220 A |
| Available diameters | 1/8, 5/32, 3/16 in |
| Manufacturer | Lincoln Electric |
| Standards compliance | AWS A5.5/A5.5M; ASME Section IX P-No. 5A; ASME B31.3 |
Applications & Industries
Excalibur 9018-B3 MR is specified for elevated-temperature and high-pressure alloy steel service:
- Petroleum refinery piping: Hydrocracker, hydrotreater, and reformer unit piping fabricated from 2¼Cr-1Mo (P22/Grade 22) alloy steel per ASME B31.3
- Power generation: High-pressure steam piping, boiler headers, and superheater elements in fossil-fuel power plants where creep resistance at elevated service temperatures is essential
- Pressure vessel fabrication: ASME Section VIII vessels in 2¼Cr-1Mo service, including reactor vessels for hydroprocessing units
- Nuclear applications: P-No. 5A components under ASME Section III where the 2¼Cr-1Mo alloy system is required
- Dissimilar metal welds: Joining 2¼Cr-1Mo to carbon steel or stainless steel components in refinery and power plant construction
Process Technology — How to Run E9018-B3
- Preheat: Mandatory — 400–600°F (205–315°C) preheat required for P22/Grade 22 alloy steel. Follow ASME B31.3 or applicable code for specific preheat and minimum interpass temperature.
- Interpass temperature: Maintain between preheat minimum and 600°F (315°C) maximum. Allow the joint to cool to this range between passes.
- Post-Weld Heat Treatment (PWHT): Required for P22 materials under ASME B31.3 and Section VIII — typically 1325–1375°F (718–746°C) for a minimum of 1 hour per inch of thickness. Confirm PWHT requirements in your WPS.
- Technique: Short arc, stringer or narrow weave beads. Limit weaving to 3× rod diameter maximum to control heat input and maintain mechanical properties.
- Low-hydrogen practice: Use electrodes directly from sealed MR packaging or from a holding oven. Maintain in heated quiver at 250–300°F between passes in the field.
- Arc restart: Re-strike at the leading edge of the previous bead crater; chip and wire brush slag between every pass.
Storage & Handling — Low-Hydrogen Electrodes
E9018-B3 MR is a low-hydrogen electrode requiring strict moisture control to prevent hydrogen-induced cold cracking (HICC) in high-strength alloy steel:
- Unopened MR cans: Store in a dry location between 40–120°F (4–49°C). Hermetically sealed MR cans maintain the H4 or H8 diffusible hydrogen level without a holding oven.
- After opening: Transfer to a holding oven at 250–300°F (121–149°C) immediately. Electrodes must be used within 4 hours of removal from a heated quiver; after 4 hours out, return to the oven for 1 hour minimum at 500–700°F (260–371°C) to recondition.
- Reconditioning: Per AWS A5.5, E8018/E9018 electrodes can be reconditioned at 700–800°F (371–427°C) for 1 hour. Do not recondition more than once.
- Field storage: Use a heated electrode quiver or pouch on the job. Keep rods dry between heats. Never leave low-hydrogen rods in open air overnight.
Frequently Asked Questions
- What does E9018-B3 mean?
- In the AWS A5.5 designation system: E = electrode, 90 = 90 ksi minimum tensile strength, 1 = all-position, 8 = low-hydrogen coating with iron powder, B3 = chromium-molybdenum alloy deposit (2.25Cr-1Mo). The B-series designators (B1, B2, B3) indicate increasing Cr-Mo content for progressive creep resistance requirements.
- What base metal does E9018-B3 weld?
- E9018-B3 is designed to weld 2¼Cr-1Mo alloy steel (ASTM A335 Grade P22, A182 Grade F22, ASME P-No. 5A) — the alloy steel specified for high-temperature refinery, power generation, and pressure vessel service where long-term creep strength above 950°F is required.
- Is PWHT required when using E9018-B3?
- Yes, in virtually all code-governed applications. ASME B31.3 and Section VIII require post-weld heat treatment for 2¼Cr-1Mo (P-No. 5A) materials to relieve residual stresses, temper the HAZ, and achieve the required creep properties. Typical PWHT: 1325–1375°F for 1 hour per inch of thickness minimum. Follow your qualified WPS.
- What does the MR designation mean on Lincoln Excalibur electrodes?
- MR (Moisture Resistant) indicates that the electrode is packaged in a hermetically sealed container that protects the low-hydrogen coating from atmospheric moisture during storage. MR-packaged electrodes maintain their hydrogen level (H4 or H8) until the can is opened, eliminating the need for oven storage of unopened stock.
- How should I store E9018-B3 after opening the can?
- After breaking the hermetic seal, transfer immediately to a holding oven at 250–300°F (121–149°C). Electrodes left at ambient conditions begin absorbing moisture within hours. Remove only the rods needed for immediate use and keep the remainder in the oven. Use within 4 hours of removal or recondition per AWS A5.5 procedures.
Browse all low-alloy electrodes: Stick Welding Electrodes & Rods — or see the Lincoln Excalibur 10018-D2 MR for higher-strength Mn-Mo low-alloy applications.