[Tmathis138]

Hello,

I work with valves (gates, stems etc..) and i do a lot of overlay including 316,410 and Stellite 6.
Recently i have been working with a gate made out of 316 SS, and i need to build up over 1/8 of Stellite 6. I am having issues though as my tip keeps overheating, melting and fusing with the wire. i have changed the diffuser multiple times and do not think this is the issue

It has been suggested to turn down the DIG, i use a 652 Miller, and also try to get ahold of Stoody and see if they suggest using a ceramic type or something specialized for Stellite.

for the piece i am preheating to about 200F
using compressed Argon
Stoody Stellite 6 wire

[Otto Nobedder]

Welcome!

I haven't worked with Stellite, so my suggestions are more general for an overheating tip. Flowing more argon will help with cooling, as will holding a bit longer stick-out (assuming you can stay within the WPS).

Contacting Stoody is definitely a good idea. If there are special alloy tips that work better at those elevated temperatures, they'll have a recommendation.

I believe a few members here may have relavent experience to share, so have patience.

Steve

[Superiorwelding]

Hello,

I work with valves (gates, stems etc..) and i do a lot of overlay including 316,410 and Stellite 6.
Recently i have been working with a gate made out of 316 SS, and i need to build up over 1/8 of Stellite 6. I am having issues though as my tip keeps overheating, melting and fusing with the wire. i have changed the diffuser multiple times and do not think this is the issue

It has been suggested to turn down the DIG, i use a 652 Miller, and also try to get ahold of Stoody and see if they suggest using a ceramic type or something specialized for Stellite.

for the piece i am preheating to about 200F
using compressed Argon
Stoody Stellite 6 wire

Tmathis138,
Welcome to the forum! Tell us about yourself, interests and experience over in the Member Intoduction section if you would.

I have a few suggestions but I am a little confused as well. Just to be sure, you are welding in the GMAW process, correct? The ONLY reason I ask is you mention compressed argon and not a mix used for mig. The other things that would be helpful to us would be your settings. Wire size, volts, amps, wire speed, gas mix and flow, etc. One reason this is important in this situation is you say you are overlaying on 1/8" material which leads me to believe one of the following; you are way to hot for the material thickness, your gas mix is incorrect causing there to be more amperage than needed (and other things) or it could also be your nozzle set up is incorrect for the process you are in (short arc or spray transfer). Another thing to consider is your burnback setting. Is is set to long causing your burnback to make it the whole way back to the contact tip burning it up?

I have never ran this particular wire but here are some suggestions on your consumables. You mention that you think you are overheating your tips causing burnback. While that is possible you would feel resistance from the tip to the wire before it finally burned back causing a failure. If this is the case I suggest more cooling time between runs. You can turn the gas up as Steve suggested but I do not feel this will help in this situation. If this is a regular job I would look into a water cooled gun. This will help with your contact tip life but also with fatigue on your hand/arm from heat. Also, your diffuser would have nothing to do with your contact tip issues, that I am aware of anyway.

Tweco has a new tip set up, Velocity that claims to have better contact (reducting heat through resistance) and the shielding gas flows through them to increase the cooling effect. From my direct experience, we use Abicor Binzel guns and consumables almost exclusively at the shop and in my garage. We noticed a HUGE increase in contact tip life with their silver coated tips. They are said to reflect and dissipate the heat increasing contact life. They are about 3 times as much as regular contact tips but will last at least 3 times as long, as long as you don't take the silver plating off. We have also sprayed their ceramic coating on these tips and spatter just falls off. Word of caution on the ceramic spray. To much will actually start to hold the heat in. I learned that the hard way.
-Jonathan

[Tmathis138]

Hey Jonathan,

Thanks for taking the time to reply to my post, I wanted to put down some more information on my work since I left it out in my first post.

Process is GMAW, the gas I am using is 100% Argon (i am not sure why the bottle says compressed Ar on it)
the Amps were set at about 28.5 and my wire speed was around 4.25. The wire is .045 Stoody flux cored wire
my pre heat is about 300F on a piece of 36" thick, by 36" diameter circular chunk of 316 SS. I need to build up an OD about 3/16 high by about 1/4" wide

I was able to get ahold of someone from Stoody, he even actually came out to the shop the following day, and he had a few things to offer on the situation

- He said since it is a flux cored wire it is relatively soft and suggested backing off the tension so the feeders don't bend or pinch the wire as it is going through.
-He also suggested using a 6 ft gun, i was using a 12 ft. He said this would also alleviate the chance of the wire getting caught up. Along with making sure the gun is as straight as possible.
-He said that pulse/spray or short arc is not necessary
-100% Argon is the suggested gas to use for this process
Suggested that the burning of the tip and wire could be caused by the pinching of the wire, or the fact that it is stuttering as it is being fed. I did notice it seemed like it was getting hung up when i just continuously fed the wire out the gun.

I am also going to be asking about some quotes on those tips and some of the water cooled guns since we are doing these projects pretty often
Thanks for all the suggestions, glad to be a part of this forum

Travis

[Superiorwelding]

Well, looks like I did indeed miss a few things in this post. I did not know this was a flux wire. I also have never heard of a 100% argon shielding gas assisted wire. That is completely new to me. I will be doing more research on this one.
I also messed up on the 1/8" part. I thought you were welding 1/8" material and not 1/8" of build up. Not sure how much I was actually helpful but we welcome you to the family.
-Jonathan