Lincoln Electric Excalibur 7018 Stick Electrode

Product Overview

Lincoln Excalibur 7018-A1 MR — What Is E7018-A1?

Lincoln Excalibur 7018-A1 MR is an AWS A5.5/A5.5M E7018-A1 H4R iron powder/low-hydrogen SMAW electrode for welding carbon-molybdenum (C-Mo) low-alloy steels on DC+ (DCEP) in all positions. The "-A1" classification designates a 0.5% molybdenum alloyed deposit — the key distinction from standard E7018 (AWS A5.1). The 0.5 Mo addition shifts Excalibur 7018-A1 from an AWS A5.1 carbon steel electrode into the AWS A5.5 low-alloy category, providing enhanced tensile strength, creep resistance, and elevated-temperature properties needed for P-No. 3 Group 1 materials (1/2 Mo steel, ASTM A204), pressure vessel steels (A302 Grade A), and applications that operate at temperatures above the carbon steel service range. The H4R designation confirms hydrogen control to ≤4 mL/100g and moisture-resistant coating for extended out-of-oven storage in field environments.

AWS Classification & Specifications

Best Applications for Lincoln Excalibur 7018-A1 MR

• P-No. 3 Group 1 pressure vessels (1/2 Mo steel): ASTM A204 Grades A, B, C — the primary low-alloy 0.5 Mo material requiring E7018-A1 matched filler for ASME Section I and Section VIII vessels

• Carbon-molybdenum piping: ASTM A335 Grade P1 (0.5 Mo chrome-moly piping) in power generation, refining, and petrochemical facilities where operating temperatures exceed mild steel service range

• Elevated temperature service (up to ~900°F / 480°C): Applications where creep resistance and 0.5 Mo alloying are required to maintain weld joint integrity at operating temperatures above the E7018 (carbon steel) service ceiling

• Power generation low-alloy steel: Turbine casings, valve bodies, and pipe connections fabricated from A204, A302 Grade A, or P1 chrome-moly materials

• H4R field welding where extended rod storage is needed: The moisture-resistant coating allows significantly longer out-of-oven exposure than standard E7018 — ideal for remote field sites and pipeline field welding where holding oven availability is limited

How to Use Excalibur 7018-A1 MR (Amperage, Polarity & Position)

• Polarity: DC+ (DCEP) ONLY — the A5.5 low-alloy designation does not permit AC operation. Use a DC welding machine. Do not attempt to run E7018-A1 on AC.

• Amperage: 1/8 in: 90–150 A. Same range as Excalibur 7018 MR. Use mid-range (100–130 A) for multi-pass structural work; higher end for flat and horizontal fill passes on thick material; lower end for vertical and overhead.

• Preheat and interpass temperature: Follow the applicable code preheat table for P-No. 3 material — typically 200–300°F (93–149°C) preheat for A204 and similar 0.5 Mo steels depending on section thickness and carbon equivalent. Interpass temperature control is critical for maintaining mechanical properties in low-alloy deposits.

• Post-weld heat treatment (PWHT): Per ASME Section VIII and applicable code, P-No. 3 materials typically require PWHT at 1100–1200°F (593–649°C) to reduce residual stress and improve toughness in the low-alloy weld deposit. Follow the applicable code and WPS for hold time and cooling rate.

• Arc length: Short arc length critical for H4 hydrogen control — same discipline as E7018 MR. Tight arc minimizes atmospheric hydrogen pickup.

• Out-of-oven time: H4R designation allows extended out-of-oven exposure (9 hours at temperatures up to 80°F per AWS D1.1 Table 4.5) compared to standard E7018. For code work, confirm the specific rod exposure limits in the applicable standard.

Storage & Handling

• R (moisture-resistant) coating advantage: The MR designation provides substantially longer out-of-oven exposure compared to standard E7018 — per AWS D1.1, H4R electrodes are allowed significantly extended time-out limits before redrying is required

• Store in sealed original packaging at ambient temperature before opening

• Once opened, store in a holding oven at 250–300°F (121–149°C) for code-critical applications; moisture-resistant coating allows longer out-of-oven exposure for general work

• For redrying: 500–800°F (260–427°C) for 1–2 hours; do not exceed manufacturer's redry temperature

• Never mix with standard E7018 — the A5.5 low-alloy classification is critical for matching base metal requirements

Compatible Base Metals & Joint Types

• Matched 0.5 Mo steels: ASTM A204 Gr. A/B/C (Mo-alloyed pressure vessel plate), A302 Gr. A (Mn-Mo plate), A335 P1 piping, A234 WP1 fittings

• Also used for: Joining P-No. 3 to P-No. 1 (carbon steel) when transitional weld metal provides sufficient tensile and toughness properties for the design

• Not for Cr-Mo steels: E7018-A1 is 0.5% Mo only, no chromium — for 1¼ Cr-½ Mo steel (P22), use E8018-B2; for 2¼ Cr-1 Mo (P22), use E9018-B3; for Grade 91 (9Cr-1Mo-V), use the appropriate Chromet electrode

• Joint types: All groove configurations and fillet welds per ASME Section IX and AWS D1.1 with appropriate WPS documentation for low-alloy materials

Frequently Asked Questions — Lincoln Excalibur 7018-A1 MR

What is E7018-A1 welding rod used for?

Lincoln Excalibur 7018-A1 MR is used for welding 0.5% molybdenum low-alloy steels — primarily ASTM A204 pressure vessel plate, A335 P1 piping, and P-No. 3 Group 1 materials in power generation, refining, and petrochemical applications where elevated-temperature creep resistance is required. The 0.5 Mo deposit exceeds plain carbon steel electrode capability for service above ~800°F.

What is the difference between E7018 and E7018-A1?

E7018 (AWS A5.1) is a carbon steel electrode with no alloying elements. E7018-A1 (AWS A5.5) contains 0.5% molybdenum in the weld deposit — this molybdenum addition improves elevated-temperature tensile strength, creep resistance, and matches the composition of 0.5 Mo low-alloy base metals. The practical difference: use E7018 for carbon steel A36/A572 structural work; use E7018-A1 for ASTM A204 and P-No. 3 pressure vessel and piping work that requires matched filler metal.

Does E7018-A1 require preheat?

For most ASTM A204 and A335 P1 0.5 Mo steel applications, preheat in the range of 200–300°F (93–149°C) is required depending on section thickness and carbon equivalent. Follow the applicable code (ASME Section VIII, ASME B31.1/B31.3, AWS D1.1) and the qualified WPS for your specific base material and joint design. Preheat for low-alloy steels is more demanding than for carbon steel due to increased hardenability.

What is H4R on an electrode?

H4 means the electrode is certified to ≤4 mL diffusible hydrogen per 100g of weld metal — the most demanding hydrogen control level in AWS A5.1/A5.5. R (moisture-resistant) means the electrode coating has been tested to maintain its low-hydrogen performance after extended atmospheric exposure (per AWS A4.3). H4R electrodes provide maximum hydrogen control combined with moisture resistance — critical for fracture-critical structural, pressure vessel, and pipeline applications.

Can E7018-A1 be used instead of E7018 on carbon steel?

Yes — E7018-A1 can be used on carbon steel and will produce a weld with adequate mechanical properties for most A36/A572 structural applications. The 0.5 Mo deposit on carbon steel does not cause problems. However, E7018-A1 (A5.5) costs more than E7018 (A5.1) and the Mo alloying provides no benefit on carbon steel — use standard E7018 for carbon steel work and reserve E7018-A1 for applications where 0.5 Mo filler is required by the WPS or code.

Does E7018-A1 require PWHT?

For code work on P-No. 3 materials (A204, P1 pipe), PWHT is typically required per ASME Section VIII and ASME B31.1/B31.3 at 1100–1200°F (593–649°C). For AWS D1.1 structural applications, PWHT requirements depend on base material, thickness, and the WPS. Always follow the applicable code and qualified WPS — PWHT on low-alloy steel is not optional for most code applications.

What Excalibur electrode should I use for 2¼ Cr-1 Mo steel (P22)?

For P22 (ASTM A387 Grade 22, A335 P22 — 2¼ Cr-1 Mo steel), use Lincoln Excalibur 9018-B3 MR (AWS E9018-B3 H4R), not E7018-A1. The B3 designation provides the matched 2.25% Cr and 1% Mo composition required for P22 base metals. E7018-A1's 0.5 Mo without chromium is not appropriate for P22 applications.

Browse all stick electrodes: Stick Welding Electrodes & Rods — see also Excalibur 7018 MR for standard carbon steel structural work, or Excalibur 9018-B3 MR for 2¼ Cr-1 Mo (P22) alloy steel applications.

Ordering Lincoln Excalibur 7018-A1 MR from WeldingMart

This Lincoln Electric product ships from WeldingMart — add Lincoln Excalibur 7018-A1 MR to your cart and place your order. We stock the Excalibur 7018-A1 MR for power generation, boiler, and pressure vessel fabricators who depend on this electrode for PWHT applications. Create a WeldingMart account to manage your order history and reorder this product quickly for ongoing project needs. In-stock Excalibur 7018-A1 orders ship same day. Select your preferred diameter and package configuration from the variant picker before adding to cart. Questions about this product before you order? Contact our welding application specialists for technical guidance.

Technical Reference & Welding Standards

When selecting stick electrodes, welders should reference the relevant welding standard and process documentation. Key technical considerations include tubing. Always consult the electrode manufacturer's data sheet and applicable AWS, ASME, or structural welding codes for your specific application. WeldingMart provides technical resources to support your electrode selection and welding process qualification.

Technical Reference & Welding Standards

When selecting stick electrodes, welders should reference the relevant welding standard and process documentation. Key technical considerations include tubing. Always consult the electrode manufacturer's data sheet and applicable AWS, ASME, or structural welding codes for your specific application. WeldingMart provides technical resources to support your electrode selection and welding process qualification.