Lincoln Electric Excalibur 7018 MR E7018 H4R Low Hydrogen Stick Electrode

Overview

Lincoln Electric Excalibur 7018 MR is a low hydrogen, iron powder type stick electrode for shielded metal arc welding (SMAW) of mild and low alloy structural steels, classified AWS A5.1 E7018 H4R. Lincoln Electric developed the MR version to improve coating integrity, with a flexible coating that resists damage and takes up less moisture than a conventional low hydrogen electrode. The manufacturer datasheet lists power generation, petrochemical, pressure piping, pressure vessels and general mild steel work as the typical applications, which describes exactly the equipment built across the Gulf region.

Seven Star LLC supplies Lincoln Electric Excalibur 7018 MR to fabrication yards, maintenance contractors and project teams in Oman and the GCC. From Muscat we can share the manufacturer datasheet, discuss diameters and package types, and help you set up storage and re-drying practice for low hydrogen electrodes in a hot, humid climate.

Why Low Hydrogen Electrodes Matter

Hydrogen dissolved in a weld can diffuse into the heat affected zone and cause delayed cold cracking, particularly in thicker, higher strength or highly restrained joints. An E7018 electrode controls this risk with a basic coating that contains very little hydrogen bearing material, plus iron powder for productivity. The designation can be read piece by piece: E for electrode, 70 for a minimum 70 ksi tensile strength, 1 for all positions, 8 for a low hydrogen potassium coating usable on AC or DC electrode positive, and H4R for a diffusible hydrogen not exceeding 4 mL per 100 g with a moisture resistance requirement.

That last suffix is where Lincoln Electric Excalibur 7018 MR stands out. Lincoln Electric lists 60 percent less moisture pickup compared with competing electrodes, extreme bendability on the 3/32, 1/8 and 5/32 inch diameters, a reduced tendency toward arc starting porosity, a clear puddle and a smooth arc. For crews that weld from open site storage boxes, a coating that tolerates humid air and rough handling saves rejected rod.

Engineering Design of the Lincoln Electric Excalibur 7018 MR Electrode

Lincoln Electric Excalibur 7018 MR consists of a mild steel core wire extruded with a basic, iron powder coating. During welding, the coating decomposes to create a gas shield and a slag that forms a protective, easily removed crust. The datasheet lists the following diameters and lengths: 3/32 inch (2.4 mm), 1/8 inch (3.2 mm), 5/32 inch (4.0 mm) and 3/16 inch (4.8 mm) at 14 inch (350 mm) length, and 7/32 inch (5.6 mm) and 1/4 inch (6.4 mm) at 18 inch (450 mm) length.

Reference packages published by the manufacturer include 1 lb plastic tubes in a 6 lb master carton, 10 lb easy open cans in a 30 lb master carton and 50 lb easy open cans. These are the manufacturer reference packages and not a statement of Seven Star stock, so please ask for the current availability of the pack you need.

Key Features of Lincoln Electric Excalibur 7018 MR

The manufacturer datasheet highlights the following for Lincoln Electric Excalibur 7018 MR:

• Improved coating integrity that keeps the coating intact in the container and on the electrode during handling.
• Extreme bendability on the three smaller diameters, reducing coating breakage when welders bend rods for tight access.
• Sixty percent less moisture pickup compared with the competition, according to Lincoln Electric.
• Reduction of arc starting porosity, which helps tack welds and short stop-start passes.
• A clear puddle and a smooth arc for slag control in vertical up and overhead work.
• Welding in all positions except vertical down on AC or DC electrode positive.
• Conformance to AWS E7018 H4R and ASME SFA-A5.1, with ship classification grades listed.
• Typical yield strength of 430 to 510 MPa and tensile strength of 510 to 605 MPa as welded.

Industrial Applications in Oman and the GCC

Power generation, petrochemical, pressure piping, pressure vessels and mild steel fabrication are the applications Lincoln Electric lists for Lincoln Electric Excalibur 7018 MR. In Oman these translate into boiler and heat recovery steam generator repairs, refinery and gas plant piping at Sohar, Duqm and Mina Al Fahal, process vessel shop work, and structural steel for industrial plants. Where a weld made with Lincoln Electric Excalibur 7018 MR must pass radiographic examination or Charpy impact testing at low temperatures, an E7018 H4R electrode with certified chemistry is a common specification.

Seven Star LLC supplies Lincoln Electric Excalibur 7018 MR together with welding power sources and spares. A modern inverter such as the Lincoln Electric Power Wave S500 supports stick welding as part of its multi-process capability, and the ESAB Rebel EMP 285ic is a portable choice for site repair crews. For regional plant owners, the Kobelco Lubricator Assembly page shows other industrial items that we handle.

Operating Procedures Printed by the Manufacturer

The datasheet recommends direct current electrode positive as the preferred polarity, with alternating current also usable. Typical currents with DC electrode positive are 70 to 110 A for 3/32 inch, 90 to 160 A for 1/8 inch, 130 to 210 A for 5/32 inch, 180 to 300 A for 3/16 inch, 250 to 330 A for 7/32 inch and 300 to 400 A for 1/4 inch. With AC the listed ranges are 80 to 120 A, 100 to 160 A, 140 to 210 A, 200 to 300 A, 270 to 370 A and 325 to 420 A. Use the lower end of the Lincoln Electric Excalibur 7018 MR ranges in vertical and overhead positions.

Technical Specifications of Lincoln Electric Excalibur 7018 MR

The table lists values printed in the Lincoln Electric Excalibur 7018 MR datasheet. Typical results are as-welded all weld metal values and are not a guarantee for a particular application.

Storage and Re-Drying Practice

Low hydrogen electrodes should be kept dry. General practice is to leave Lincoln Electric Excalibur 7018 MR in its sealed can or tube until needed, then keep opened electrodes in a heated holding oven at the temperature recommended by the manufacturer, and to follow the electrode maker’s re-drying instructions for any exposed rods. Because the coating of Lincoln Electric Excalibur 7018 MR is designed to resist moisture pickup, it forgives short exposures better than ordinary 7018 types, but it is not a substitute for proper storage on critical pressure part welds. This is general welding guidance and not a Lincoln Electric warranty statement; check the manufacturer instructions for specific times and temperatures.

Call To Action

To order Lincoln Electric Excalibur 7018 MR, tell Seven Star LLC the diameter, pack type, quantity and delivery location, and our Muscat team will prepare a formal quotation and confirm availability across Oman and the GCC. The manufacturer datasheet is attached to this page. Seven Star LLC supplies Lincoln Electric as a trusted supplier with engineering support in Muscat, so contact us with your enquiry and welding procedure requirements.