MCAW classification?

Date 08-15-2007 17:40

Unless it has a significant amount of fluxing ingredients, a metal cored wire would be considered a GMAW wire, but rather than the "R" designation, it would have a "C".

For example, 309L stainless wire is "ER309L" in A5.9 if it solid, and "EC309L" if it is metal cored. If it contains fluxing ingredients, then it becomes E309LTX-X in A5.22 (the X's would denote shielding and positional designations).

I don't know about CWB.

By hamilton (*)

Date 08-17-2007 20:33

I worked 5 years as Welding Procedure Engineer in the CWB, so let me answer your question here:

In new CSA W59.03 Standard, MCAW has been recognized a seperate process, so it is not FCAW or GMAW. Latest CSA W48 "Standard for filler metal" also shown metal cored wires as part of MCAW process.

That's why, if you check my Canadian site http://www.weldcanada.com , you will see MCAW is considered a seperate process.

Of course in AWS D1.1, metal cored wire as well as solid wire are considered GMAW

Hamilton

By darren

Date 08-18-2007 08:21

we are covered for mc under our fc ticket at our shop which i don't agree with because mc is a totally different animal.
darren

By PhilThomas (**)

Date 08-18-2007 11:06

Interesting - thanks for the information :)

What is the breakpoint between metal cored and flux cored compositions? I seem to remember something like "5% or more of slag ingredients in the fill" but can't lay my hands on it.

By js55

Date 08-20-2007 14:08

Phil,
Thats an interesting number. I had never heard that before but it doesn't surprise me. In my opinion if there is any fluxing agents 'AT ALL' it should be considered a FC, so that the only difference between a solid and MC is essentially arc density, which is the primary reason for increased deposition rates. For years though I know that manufacturers have been trying to find a way to make MC position capable. I just don't see that its possible without fast freezers. In which case, its FC.

By PhilThomas (**)

Date 08-20-2007 15:05

I still haven't found the referencce I am looking for, but in A3.0-2001 terms and definitions, it says fcaw has "an extensive slag covering" while metal cored wires produce no more than "slag islands"

By js55

Date 08-20-2007 15:32

Phil,
Perhaps the fuzziness of the definition argues for a seperate spec. Si added as a deox to solids or MC's also wets, also strengthens ( a primary purpose to FC additions), so does Ti. Ti will also, when added in certain amounts cause the formation of acicular ferrite increasing toughness, as does Al.
But on the other hand, how important is it?

By Lawrence (*****)

Date 08-20-2007 16:57

We have had some trials with 0.045 MCAW run Vert-up with GMAW-P. It performed just fine, which is to say about the same as solid wire. GMAW-P out of position is not a very high speed process when compared with flat and horizontal rates.

No way does it compare with 0.045 FCAW for V-up deposition rates. I am also more confident in FCAW sidewall fusion out of position.

By js55

Date 08-20-2007 17:15

Lawrence,
Pulsing would work to render it positional, to be sure. Just as short circuit probably would. Though I have never SC'd MC.