Classification of Flux-Cored Arc Welding (FCAW) Wires

 Type R

• Gives the highest productivity in positional welding.
• High efficiency due to easy slag detachability, welding properties, and ease to mechanize.
• Minimum spatter.
• Different slag systems: high or low solidification temperature gives different properties.
• Designed for single-pass and multi‐pass welds in the positions of flat butt, flat fillet and horizontal.
• They are designed for use with CO2 but can also be used with mixtures of Ar+CO2.
• Improving the transfer in the arc and reducing spatter.

Type P

• Type P is similar to Type R, but Rutile slag is designed for rapid cooling, allowing welding in all positions.
• Generally, these wire electrodes are produced in lower diameters and have a spray transfer when used with CO2.
• When recommended by the manufacturer, the use of mixtures of Ar + CO2 can improve the operational characteristics of the electrode wire, reducing spatter.

Type B

• They are characterized by a metal transfer drop‐spray, with the weld beam top surface slightly convex and slag that may not completely cover the surface of the weld.
• These wire electrodes can be used in all positions PA /PB / PC and in multi‐pass welding.
• With protection CO2 gas, or mixtures Ar + CO2. The composition of the slag consists of fluorides and alkali metal oxides. The deposits of these cored wire electrodes show excellent resistance to impact (toughness/resilience) and good resistance to cracking in general.

Type M

• They are characterized by a spray transfer of very fine drops and a minimum slag thickness.
• The composition of the flux inside these wires consists of alloys and iron powder, allowing high speeds fusion without the danger of the appearance of lack of fusion.

• These wires are used with the protection of gaseous CO2 or Ar + CO2.
•  Used primarily in positions flat butt, flat fillet and horizontally, in terms of the single pass.
• The worst penetration.

Type V

• They are used without protective gas and allow a transfer of metal that goes from the globular to slightly spraying.
• The slag produced by these wires electrodes is characterized by a range of solidification rates from slow to fast.
• The wires with slag to cool slowly are used in all positions in the single-pass welding of galvanized steel and steel with aluminum or other coatings.

Type W

• They are used without shielding gas, allowing a metal transfer between the globular and close to spraying.
• Its basic slag fluoride was designed to allow high deposition rates.
• Some wires have added iron powder to inner fluxes providing good operational characteristics.
• The wires of this type are used in welding single-pass and multi-pass positions flat butt, flat fillet and horizontally, with some of these wires can weld vertically downward.

Source: https://amarineblog.com/2017/09/15/welding-inspector-wps-part-8-final/

Type Y

• They are used without shielding gas and allow a transfer of metal almost spray.
• Its basic slag fluoride was designed to allow single-pass welding and multi-pass in all positions.
• They provide good resistance to cracking and good impact strength at low temperatures.