nomad09

Hey guys, been trying to find more info on this as we didnt really cover pulsing in school. I work at a fab shop were we do alot of stainless and our lead welder insists tht low speed pulsing is better and keeps heat down more then high speed. I would have to agree with him on tht certian situations it is better, I.E Thicker material where u need more grunt to get through but dont want any warping. I told him this and then went to say that higher speed pulse actually reduces heat input. He instantly told me i was wrong. Now the little we did cover in school would lead me to believe that i was right. I just had no way of telling him so he would understand. Hes kinda an old school welder but i believe that if i can prove it to him through words ( mainly cause i cant show him, im not as good as him and well hes biased so naturally would make his way work) Hell give it a shot and our products will improve and costs of cleaning up haz areas on food grade will decrease. Anyone shed some light on this for me?

sanchoem1

I've messed with high and low pulse rates, and didn't really notice a difference. I also am relatively new to the world of tig welding. It never hurts to try both and decide with real tangible evidince

I'm sure people with lot's of experience will chime in soon!

ToxicFabrication

I personally don't use high speed pulse. I feel it not only takes heat out of the peace, but also your using higher amps to get the same penetration from what i can see.

Example, if im using 75-80 amps of constant heat to get good pentatration, it takes more like 90-100amps while using 200-500pps. I'm more of a fan of constant heat. For flange welds I use more of a slow foot pulse. Hope this helps. They both have there ups and downs.
-collin

damnraz

You can create an autogenous weld using high PPS for butt welds. If the weld schedule is correct you'll have added reinforcement and significant drop through with smaller HAZ without having to add filler. Just run a test on a few coupons and check the difference in the HAZ area so you'll have a better understanding on how high pulsing has its advantages. Makes a big difference in welding thin gauge stuff where warping is a big issue. Thick stuff, I wouldn't worry about it but you can achieve a narrower weld with 100% penetration with high pulsing because of agitation to the weld pool.

damnraz

That depends on how you set your peak and background percent time. That greatly affects how much input is required to get good penetration with a smaller HAZ. 90-100amps isn't really 90-100amps unless your at 100% background and 100% peak.

frostyrb

i use high speed pulse like 1000pps on 16 to 18 gauge stainless for a fusion weld. i hate slow speed pulse because it screws my rhythm up. i do production work fusing at 1000pps & have minimum warpage & all the parts are within the same specs. if i have to use filler on real thin stainless i will use aroung 500pps & weld small sections moving around alot. that's what seems to work for me, but i mostly only weld aluminum, so i see very little stainless sheet. about this one big production job for 2 weeks every year. if i where you i would mess around with the different pulse speeds & see what gives you the best results.

HickamHatch

My welder only goes to 15pps... I use slower on thicker and faster on thinner if that helps. The slower it pulses it seems like it has more time to penetrate.

all_motor_mike

on sch 10 and 40 i dont pulse, on 16 and 18 gage stuff i will pulse at about 250pps though. i never went to welding school or anything so i dont know much about all the differnt adjustabilities on modern welders but it seems to me that u have a little more control over the arc and yes u do need to use more heat then u would if u were not high speed pulsing. damnraz can u explain what the background and peak percentages are and what the do to the weld puddle or arc?


mike

damnraz

The percentages are on time. Lets say your welding at 1.0 pulses per second with the background set at 25% and the peak set at 75% at 50 amps. If you're running a bead and want to convert that to amps it would mean you're running 12.5 amps background and peak (your hottest) at 37.5 amps at 1.0 pulses per second.

Since PPS is set to 1.0 when you count to 1 it should be at it's peak amperage at 37.5 amps, after, it will draw back to 12.5 amps and the process keeps going on and on and on until you've completed your weld.

So 50 amps, isn't really 50 amps when you're pulsing.

Just imagine what advantages that would give you, as the welder trying to weld thin gauge or thick gauge steel. For thin and thick, pulsing agitates the weld, allowing you to weld faster because the puddle is formed quickly. Welding faster with pulsing allows for minimal distortion and more penetration if the correct parameters are set for your material. Pulsing dissipates heat quicker allowing for a smaller heat affected zone.

I'm not no weld engineer or have ever been to weld school. I've been welding for 7 years in the aerospace industry and this is just all coming from experience. Don't take my word for it and believe what I am saying is true. Do some research, practice on a couple pieces with different settings and define what advantages/disadvantages pulsing has for you.

Some people like it, some people don't or really don't have any need for it for what they're doing.

9bells

mostly right....

The Parameters are as follows:
Peak Time
Peak Amperage
PPS
Background % (based on the peak amperage)

So, with your 50 amp example, the 75% is the amount of the 1 second pulse spent at 50 amps. The 25% background is correct, 12.5 amps, and it therefore is at 12.5 amps for the remaining 25% of the 1 second pulse rate(PPS).
The whole benefit of pulse is cool down between the peaks. Therefore, it is most useful to run a relatively low background % to allow for this.
The pulse rate has to match travel speed. So, if you are travelling quickly with an autogenous groove weld, you would set the rate relatively high. If you are travelling slow on thicker material, then fewer pulses per second will allow burn-in time on the peak for penetration.
Of course, there are situations where you may need a unique combination.
Also, it should be mentioned that pulsing at very close to your non-pulse amperage is not beneficial. The idea is to give the weld zone a blast of short-term, high-amperage to achieve the needed penetration, then a brief time at next to no amperage to allow for cooling. If you weld at 45 amps normally, try 60 amps when pulsing, or higher.

Marlon88

This thread has some very good info.

So any of you experienced guys might tell us beginners a few pointers on what settings shall we set our machines? Lets just say we want to butt weld 2mm (14g) stainless steel, what figures we have to set our machines at just so we can get things started?

Peak Time
Peak Amperage
PPS
Background %

Don't want to hi jack the thread but even the op can find this info very useful.

10.2replicaR

I let mine auto pulse, if i set the pulse i dont seem to get good penetration.

HickamHatch

Auto pulse? What welding machine has that?

Fabian

http://www.weldingtipsandtricks.com/...ent-pulse.html check this site with some info on pulse...and everything else!

javierb14

Welded some runners today on the Dynasty 200DX with high speed pulse. Settings: Current=65, 225 pps, 60% peak time, and 45 % background. Material was 304 0.065 wall tubing. I like it...going to keep screwing around with it to dial it in.

damnraz

Looking good Javier, see any benefits from pulsing yet? I wonder if you can get a hold of .035 wire and run about 1/2 or 3/4 of that weld width. That's my personal preference but weld looks great overall.

damnraz

Thanks for correcting me 9bells, you are right on the money!

javierb14

Seat of the pants tells me that travel speed is faster, but I have no data to back it up. I used 0.045 filler on those welds. I have used lengths of .035 mig wire before as TIG filler, but the curvature of the wire threw me for a loop I just checked and looks like the lws store can special order .023, .030, and .035 dia. wire...ordering some on Mon.!

Seymour86

I have found that Low speed pulse helps with heat distortion where as a rate higher than 50pps helps stablize the arc. But thats just the way I feel about it.

Baxt3r

After quite a bit of experimentation I've found that my travel speed is much faster not pulsing. I also work with 14, 16 an 18 gauge stainless sheetmetal and have gone away from using the pulse setting on my machine. This is mainly 100% due to speed, however to control warping I use an array of different aluminum billets/bars/scraps placed right next to my bead to draw the heat out the sheet. I also find that my puddle burns much cooler using a gas lens rather than a conventional cup. When welding an outside 90 degree butt weld I seldom if ever point my torch directly down at the joint. I blow across the peak of the joint from the side so the main focus of the heat isnt going directly into the part. This also cuts down on getting any blow thru on the back side of the weld which is my greatest concern. This obviously doesnt address using the pulse setting but these are ways that I've found very useful for pulling heat out of my part and reducing warping while being able to complete my welding at what I feel is a faster rate by not using the pulse setting.