With the ever increasing cost of helium it would be wise to reduce the percentage down.
I have many customers that used 75/25 Ar to Helium mix for welding with 4043 and 5356 filler metal.
If you are doing GTAW or GMAW it will show little difference with the lower helium mix, you will have to adjust parameters.
I have one customer who is using 90/10 Ar to Helium and welding 6061 with 5356 and likes it better.
Helium will increase in price every year and the more they use for MRI machines and the Collider the less for welding.
The governments wells maybe capped at some point if they do find other reserves like the one in Africa.
The less helium you use the more profit margin you will gain by using Argon.
To speak *around* Electrode's excellent points, Lemme say this about that:
Welding Speed?
Deposition Rate?
Cost?
YOU HAVE NOT TOLD US ANYTHING ABOUT THE PROJECT... NOT PROCESS, NOT PARAMETERS, NOTHING.
We don't/cant judge anything unless we know if you are:
1) Running at maximum efficiency with your current high helium mix of shield gas
2) Does helium addition make possible higher travel speed and deposition rates with GMAW or GTAW? It sure can, IF, IF, IF if if if--- the procedures are carried out with great process control, matching the PQR trials that demonstrated the excellence in the first place.... This is almost never done... The helium is just money pissed away.
GMAW deposition rates with Helium of 20 years ago (1996 ain't that long ago) can be matched with modern GMAWP and pure argon, especially in automated situations.
GTAW deposition rates and fillet sizes with helium of 20 years ago can be matched today by straight argon and asymmetric AC GTAW power supplies,,, But only if the operator can produce at a consistent travel speed... This was the case with Helium and is now the case with Asymmetric power
Improved penetration? Exactly what kind of "improved" penetration is required beyond, fusion at the root of a fillet and side walls on groove welds? High speed GMAW does have some better toe fusion with helium gas, but so few people actually run the automated GMAW at maximum travel speeds and could use argon 100% and get the same quality... Again, especially if GMAWP is brought into the conversation.
I'm doubtful your production is going on at the ragged edge of technical possibility, where the addition of Helium into your gas mix is the single factor that makes the difference between quality or productivity or the lack thereof. But who knows maybe you are... But we can't tell by the information you have shared.
Understood and sorry about the absence of data, but im asking about the idea theoretically since i dont have any test data, of which i was hoping some of you guys have already tested before and hopefully share some data & analysis. Quite new to this welding industry. My passion is really into production/operation continuous improvements and just happen to initiate this now on opportunities related to welding.
Just exploring the feasibility of the idea before I make any next steps which of course will involve cost, time, etc.
Yeah, will try that GMAWP +100% Argon, (+mechanization) soon.
That's right, great process control are needed.
If you are attempting to improve the penetration in aluminum, use spray mode transfer with a larger electrode diameter rather than pulse transfer.
Pulse spray is used to limit the heat input which is key when welding materials with low thermal conductivity such as austenitic stainless steel and carbon steel. The pulse spray reduces heat input thereby allowing the welder to weld in all positions and still achieve good fusion. Aluminum usually needs more heat rather than less heat to ensure proper fusion.
I see too many situations where pulse spray is used to make life more comfortable for the welder, but the need for proper fusion takes a back seat to good welds.
Just my observations.
Al
A good conversation. And an excellent debate :)
What GMAWP also offers for aluminum is:
1, The ability to produce a spray transfer weld with a significantly shorter arc length, consistently. The results and benefits include; Smaller fillet sizes at higher travel speeds than can be accomplished with traditional spray transfer at any current. This is an especially important function for aluminum welding, where traditional spray transfer often produces overly large and concave fillets, meaning that weld sizes in production often exceed the designed size and that concave profiles are more prone to cracking as the joints age and are subject to cyclic loading. (look at a semi trailer)
2, Weld bead appearance. It is impossible to ignore the fact that a great fraction of products made with aluminum have a requirement of a "rippled" weld face. Traditional spray transfer can only accomplish this by the operator or robot whipping the gun forward and back along the weld axis. The result is oxidation during the whipping and also increases heat input, also there will be varied penetration profiles corresponding with the "whips" that result in lack of root and sidewall fusion even at very high current levels. GMAWP on the other hand can pulse current and WFS in some cases to produce a weld bead profile that meets customer requirements for appearance, while at the same time improving fusion at the root and productivity due to controllable weld size in manual operations, all with a straight push at a consistent speed along the axis of the weld joint.
It's also important to note..(for steel and aluminum) That with GMAWP a lower current is not always found at wire feed speeds matched to traditional spray.. Often the current for a given electrode diameter and WFS is the same, the difference between GMAW and GMAWP lies in the shape of the arc and the profile of both the crown and the penetration.
Saying "pulsed spray is used to limit heat input" is a statement that is too broad... GMAWP can do that, but there are uncounted waveforms that produce results from lesser to even greater energy input for a given WFS.
Pulsed spray is used to produce a weld deposit that is "different" than traditional spray transfer... It's not a silver bullet, and it is not necessary or beneficial for every application... For much or even most carbon steel, GMAWP is of little benefit. But if high travel speeds or small fillets are required, it may be a good option.
GMAWP may or may not be the answer... But walking away from a possible solution that will increase quality and productivity while paying for itself in short order isn't something I'm willing to abide.
Old paradigms must take a back seat to relevant proven welding facts.
