metal-cored arc welding

Metal-cored Arc Welding Overview

Metal-cored Arc Welding is a welding process that uses heat for joining metals. MCAW is another variant of the MIG welding and MAG welding processes. More specifically, metal-cored Arc Welding is a technique that employs heat for joining metals and DC electric arc produces it. Next, the arc is attached to both the work peace and a consumable filler wire feeding continuously.  Further, a shielding gas is released which protects the molten weld pool from atmospheric contamination.

As mentioned, MCAW is another version, not the same, of MIG welding type. Notably, MCAW performs based on a wider range of shielding gases and provides more flexibility with alloy compositions. Besides this, both have many fundamental differences despite having some common features.


Post Highlights:

  • What is Metal-cored Wire?
  • Mixtures of Shielding Gases for MCAW Process
  • Metal-cored Arc Welding Equipment
  • MCAW Operating Modes
  • Metal-cored Wire Features
  • Blueshield Metal-cored Wire Work
  • Boost MCAW Welding Productivity
  • Applications of MCAW
  • MCAW Process Advantages
  • MCAW Welding Career Prospects
  • Job Types for MCAW Welding
  • Salary of MCAW Welders

What is Metal-cored Wire?

The wire is a tubular electrode that carries a metal sheath and various powdered materials in its core. And it consists of most of the quantity of iron.

Shielding Gases Mixtures for MCAW Process

Choosing proper shielding gas plays a crucial part in welding and durability. These gases protect the welded part from the effect of atmospheric oxygen and nitrogen. The mixture of the following gases is required in welding.

  • Argon 4.6
  • CORGON 10
  • CORGON 12S2
  • CORGON 18
  • CORGON 25
  • CORGON 5S2
  • CRONIGON 2
  • VARIGON H2
  • VARIGON H5
  • VARIGON He30
  • VARIGON He50
  • VARIGON He70
  • VARIGON N2.5

Metal-cored Arc Welding Equipment

Equipment and accessories are the main role players in the welding process. MCAW equipment comprises continue wire, gas cylinder, power cable, wire feed unit, gas hose, welding torch, torch conduit, Arc, earth cleaner, work-piece, and return cable.

Operating Modes of Metal-cored Arc Welding

MCAW type has mainly two modes i.e. dip transfer mode and the spray transfer mode.

  • In Dip Transfer Mode, the electrodes make short-circuit with the pool of weld at a controlled frequency. It happens due to the settings of arc voltage and low current.
  • In Spray Transfer Mode, an electromagnetic force projects metal from the tip of the wire in form of a stream of discrete droplets. It is nearly the same size of equal to wire diameter.

Metal-cored Wire Features

The features of the MCAW type are as follows.

  • MCAW leaves no slag and spatter.
  • Almost, there is no post-weld cleanup.
  • It can bridge part gaps without burn-through.
  • The process provides high travel speeds and deposition rates.
  • It provides excellent root penetration and side-wall fusion.
  • Welding with this wire can weld thin materials at high amperages without burn-through.

How does Blueshield Metal-cored Wire Work?

Blueshield metal-cored wires offer both good weld quality and performance. In addition, it provides good results to welders extremely demanding a high-speed, wants to use it in semi-automatic or robotic welding applications.

1. Blueshield Metal-cored Wire Classifications

Name Type AWS Class Position Application
LA C-3M Metal-cored E70C-3M-H8 Flat or horizontal, all-position welding using short-circuit or pulsed-spray transfer. Used for similar welding applications as LA S-3 MIG wire.
LA C-6 Metal-cored E70C-6M-H4, E70C-6-H4 Flat or horizontal, all-position welding using short-circuit or pulsed-spray transfer. A good, high-speed,

general-purpose single- and multi-pass semi-automatic and automatic mild-steel welding wire. Weld metal mechanical properties are like those of LA S-6 MIG wire.

LA C-6LF Metal-cored E70C-6M-H4, E70C-6-H4 Flat or horizontal, all-position welding using short-circuit or pulsed-spray transfer. An excellent low-fume, high-speed semi-automatic, and automatic mild-steel welding wire. Weld mechanical properties are like those of LA S-6 MIG wire. Applications include car and truck frames, structural steel and trailers.
LA C-6CT Metal-cored E70C-6M-H4, E70C-6-H4 Flat or horizontal, all-position welding using short-circuit or pulsed-spray transfer. Similar welding applications as LA C-6, offering lower temperature mechanical properties down to -40°C (-40°F).
LA C-6CR Metal-cored E70C-6M-H4, E70C-6-H4 Flat or horizontal, all-position welding using short-circuit or pulsed-spray transfer. For welding over rust, mill scale and other contaminants typically found in harsh environments, such as structural steel fabrication, maintenance, and repair.

 2. Blueshield Low-Alloy Steel Metal-Cored Wire Classifications

Name Type AWS Class Position Application
LA 80C-W Metal-cored, low-alloy steels E80C-G-H8 Flat or horizontal Used to weld weathering grade steels
LA 80 C-Ni1 Metal-cored, low-alloy steels, 1% nickel E80C-Ni1-H4 Flat or horizontal For welding high-strength steels requiring weld metal toughness properties down to -40°C (-40°F).
LA 80 C-Ni2 Metal-cored, low-alloy steels, 2% nickel E80C-Ni2-H8

 

Flat or horizontal For welding high-strength micro-alloy steels requiring weld metal toughness properties down to -50°C (-60°F).
LA 90C-B3 Metal-cored, low-alloy steels, 2 1/4 Cr / 1% Mo E90C-B3-H16 Flat or horizontal Used to weld Cr/Mo steels in high-temperature and high-pressure piping applications.
LA 90 C-M Metal-cored, low-alloy steels E90C-G-H8 Flat or horizontal High-strength steels with a minimum tensile strength of 620 MPa (90 ksi). Impact requirement: -50ºC (-60ºF).
LA 100 C-MG Metal-cored, low-alloy steels E100C-G-H4 Flat or horizontal For welding high-strength steels with a minimum tensile strength of 690 MPa (100 ksi)
LA 110 C-MG Metal-cored, low-alloy steels E110C-G-H8 Flat or horizontal For welding high-strength low-alloy steels such as ASTM, A514.

Tips to Boost MCAW Productivity

Boosting productivity requires certain parameters. They consist of a range of tested and proved MCAW welding gases such as CRONIGON®, CORGON®, VARIGON®, and FORMIER® families. The mixes are designed and aimed to bring the full benefits and added flexibility to MCAW welding. The mixture includes a good weld profile, good fusion, good arc stability, and alloying additions from the core. So, using the above-mentioned things, a welder can boost MCAW productivity to the desired level.

Applications of Metal-cored Arc Welding Type

MCAW is employed mainly to lay welds alloy steels, carbon-manganese, carbon and may also be used on some stainless-steel grades. But the success rate depends on things like the selection of application technique, polarity on the power source, shielding gas, power source, and right consumables. Besides this, good materials from reputed manufacturers and by following special standards can increase the MCAW productivity.

Metal-cored Arc Welding Advantages

  • MCAW has a high welding speed and duty cycle.
  • Metal-cored Arc Welding gives a nice bead appearance.
  • The process provides high productivity with low heat input.
  • MCAW welding high deposition efficiency and deposition rate.
  • It is suitable for galvanized and aluminized materials.
  • MCAW welding lays low spatter levels and low slag volume.

Metal Cored Wires Disadvantages

  • MCAW requires an automated or robotic setup for gaining the fullest potential benefits. Without it the productivity is average.
  • Next, welders must to keep automated systems consistent without breaks and tiring while welding.
  • Another drawback is a repetition of an application that is necessary to minimize setup and jig costs.

MCAW Process Employment Areas

  • Ship Building Companies
  • Aerospace Companies
  • Construction Industry
  • Vessel Making Companies
  • Pipe Making Companies
  • Equipment Repair Companies
  • Welding Schools

Job Types for MCAW Welding

MCAW Welder Salary Information

The earnings and paychecks vary in the welding industry. It depends on various factors like market trends, location of the company, the number of companies in that area i.e. competition, etc. Take a look at an hourly salary of the different positions in the industry.

Position Salary (US$/hour)
MIG Welder US$16 per hour
Robotic Welding Technician US$18.39 per hour
Shop Welder US$ 23.00 per hour
Structural Fitter/Welder US$19.34 per hour

Thus, the above-mentioned various aspects of the Metal-cored Arc Welding are important and beneficial for students, applicants, welders, and professionals in the industry.

Related: Other Welding Types

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