Hello everyone. I'm glad I found a site like this in order to share process issues and ask for suggestions (and offer them also! )Situation is as follow:We produce a wire ring (w/ SAE 1060), which is welded w/o any filler. There're just a couple electrodes that heat up the material, and its welded. We've been having spatter in some of the rings, and this has lead to issues while on testing, because there are some zones in which an incomplete weld can be found.Parameters we control on the process are:1. Welding amperage (~26A)2. Clamp pressure (~80 psi)3. Anneal amperage (~4A)4. Distance between electrodesIs there any way in which we can avoid the formation of said spatter? If so, which one would be?Any info and/or input will be VERY appreciated!
Reply:Try adjusting the amperage up a little at a time is what I would suggest but without knowing what the actual welding process is ( mig tig stick ) I / we wont be able to help very effectively.
Reply:Is this a job that used to be performed here? Now you want info on how to do it?Figure it out. Go to school, learn from an experienced welder in the department.Don't have that... ask the world wide web............................................... ...Tim Beeker.
Reply:I'm having issues with determining what your asking for specifically. Because I do not understand what it is your welding, or the process.SMAW?GTAW?GMAW?FCAW?What material are you welding? Carbon steel, stainless, aluminum?How is the material prepped?Please excuse tnjind for the moment.It's always troublesome dealing with question from Latin countries because we've lost so much production and labor afar and abroad. Latin countries have undoubtedtly changed the face of America and in many ways, and not for the betterment of us as workers. We are now losing welding jobs to Latins in the southwest because of the underbidding of work, and in turn there is a devalueing of our profession that many of us here on weldingweb feed our families with. Working under the table, not paying taxes, and welding at an inferior level, and etc.....etc...I could go on and on about this, that, and the other thing. Latins have done plenty to help bring this country to its knees. We've had just as much a hand in it through our government officials, and flat out selling out by our industry leaders, and our unions. With that said, this is the internet and not a jobsite. So, please post with better detail and I at least, and I'm sure some others will try to help.The simple answer appears to be add shielding gas.The issues your having on testing?Are they on/in QC or are they in qualifying a welder, or process?As the addage goes; a picture is worth a thousand words....Take a picture and post it. It'll certainly help clarify.Last edited by jsm11; 06-15-2011 at 08:38 AM.1981 Lincoln SA 200Miller Trailblazer 302gMiller 211 Mig Welder w/ AutosetI'm learning to stick metal together
Reply:Thanks for the replies, guys. maybe the situation gets clarified if I tell you that we are an automotive springs and parts manufacturer.Machine we are currently using is shown in the picture:1. Ring being welded2. Amperage monitor3. Clamp pressure manometer4. PistonsProcess consists of placing the wire ring, allow pistons to clamp the wire, heat it via induction and weld.Allow me to answer all your questions in order
Big65mopar: A Design of Experiments has already been performed, so we already know which amperage is the best for the application. (the 26A that were previously stated)@tnjind: Nope, this job has always been performed in Mexico. This ring goes inside a car clutch and we've been having issues with them. Were we to have a more experienced welder, you bet that'd've been my choice of asking. I followed your suggestion, search for it on the web, and found WeldingWeb.@jsm11: As stated, material being welded is SAE 1060, that is, carbon steel.Only preparation that is done to the wire is a wash to remove all dirt. Sometimes the wire is also covered in soap, which is also removed.I also thought of the shielding gas, but since the price of this automotive component is dirt-cheap, using gas would not be an option.Sometimes, the weld toe embrittles and we have spatter in the regions adjacent to the weld. At first we tried checking for oxygen content but the testing was non-conclusive.Since this part goes inside cars , it needs to comply with a minimum applied force (12 kN, around 2700 lbf). The usual testing that is performed on the ring is a tension test, that is, its mounted on a circular base and then pulled apart by a tensile tester until it breaks.Regarding the problems, we've had engine testing failures, and the aim is to eliminate any source of variation (such as spatter, or welding voids).
Reply:This is interesting! Am I right in thinking there is no secondary trim or coin operation like you would have with a resistance type spot welding machine?Anyway,it's a purpose built operation and you can only vary amps, time, pressure and materials. If I built it and had it working well, I'd probably blame the problem on the 1060 having too many residuals in it... that doesn't help much.How long has this been operating?Matt
Reply:The machine is, as you say, custom-made for this application.This machine has been working since ~2008.Regarding the quality of the base material I could say that, surface-wise, it has no discernible inclusions, laps, die marks, or seams. Metallurgically it may be very dirty since its plain steel, nothing fancy; chemistry-wise it is also compliant with SAE, so no big sulfur- or phosphorus- embrittlement.
Reply:Sorry! I also forgot to mention that, afterwards, the ring is annealed in a similar-looking machine, only at lower amperage (7A) and with current applied only for 2 seconds.
Reply:When you say spatter, do you mean material is ejected or eruptions around the weld joint when liquidus? Or is it voids and inclusions inside the weld itself?I am not familiar with this process at all. Spot welding machines would complain if the material was not very consistant. Things like contamination, very high dewpoints or wet steel could also cause big troubles too.Wish I could be more help.Matt
Reply:Hey MattYep, I mean spatter as material ejected. Sometimes, said spatter causes us voiding or unwelded sections on the wire.To avoid contamination and moisture, the wire is washed to eliminate any dirt and then dried.
Reply:Could you post a picture of hte spatter you are talking about?Mechanical Engineer
Reply:I am also not familiar with that machine, wish I could be helpful, as usual I am not.Moisture does sound like it could be the culprit. I am also assuming that the welding is done in open atmosphere.Tim Beeker.
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BLUE2KSS: here's how the spatter looks like@tnjind: had the wire any moisture I would completely agree with you. Nonetheless, there is none, unless you would like to imagine that the NaOH that is present in the washing solution (and sometimes present, dry, as a by-product in the wire surface) may decompose into water vapor because of the heat generated.
Reply:Excerpt from the Troubleshooting section of Millers Handbook for Resistance Spot Welding:Spatter or molten material being expelled out during welding operation.1.Incorrect tip alignment. Dress tips so that they align and are flat on the material.2.Excessive tong pressure. Reduce tong pressure.3.Output amperage too high. Reduce amperage setting.4.Weld time too long. Reduce weld time.Hole in middle of weld. 1.Contact area of tips is too large. Change to a smaller tip diameter or dress tips back to original diameter.
Reply:Soaps of that type tend to absorb water from the air.
Reply:I was wondering about humidity, but I have nothing to offer but speculation.Tim Beeker.
Reply:Judging from the location of the "fissure" and where the "spatter" landed, it looks more to me like substandard materials?? Almost like foreign inclusions from the foundry process and impure. Some random material embedded into the base material and then when heated, it popped before the base material.Just a guess.Granthttp://jackalopefab.com/MM210Synchrowave 200DXMiller XMT350 w/60series feederMiller Bobcat 250 with SGA 100 and spoolgunHTP PlasmaFull Machine shop with everything
Reply:Ouch! I would be upset if my machine gave me the weld above...I doesn't look anything like a failed resistance weld except for sometimes a resistance welder gets out of register (one side has more mass to contact than the other) and both legs don't get to the right heat before pressing. Then one side will flash out more than the other.Could it be that the joint or the inductor coil can move around and not have everything in the right place?BTW that looks like it does need a trim or coin operation after welding if ring section is important.I would also send a pic to the machine maker, it could be something silly simple.Matt
Reply:I would say after your cleaning prosess square the ends scuff them with sctotchbrite or steelwool then do a small preheat say maybe around 110 or120 degrees farenhiet
Reply:Thanks for all the help, guys! I'd never thought to have so many responses.@Bluewelders, tnjind: I'm doing a couple experiments to check how much water would the soap absorb, in order to verify that supposition.@jackalope: while the material we use here is plain carbon steel wire, it is supplied according to a inclusion standard, so there are no big inclusions in the wire surface (can't say anything about an inclusion in the inner part of the wire, tho). Let me mount a wire section and I'll let you know (i'll post a picture if able! the microscope camera is moody today) what comes out of this.@Matt: the issue here, mate, is that the machine was "customized" by our Mant. guys here, so it's more of a mongrel. We do have an spec regarding flash size (no larger than 0.05 in). The suggestion you make regarding a way to "freeze" in place the arrangement in order for it not to shift position makes sense, I will change that in the machine.@puddlemutt: the cleaning process starts with the wire "coiled" (that is, formed into circles); afterwards, we put the wire "slinky" (that's what it looks like) in a die, and cut it, to make separate rings. Therefore, in the metal-to-metal interface you have clean base material, but it may be useful to clean the wire body, but I'd rather go with a chemical instead of mechanical processing. The wire size is 0.118" and the customer won't allow a variation of more than 0.0012"
Reply:Originally Posted by Big65moparTry adjusting the amperage up a little at a time is what I would suggest but without knowing what the actual welding process is ( mig tig stick ) I / we wont be able to help very effectively.
Reply:I do not like the fixture. As for the tolerance given it is crazy because all welding results in shrinkage.There are manufacturers that just make these kind of rings. You need to call them.The two electrodes come downwards onto the ring.the ring gets hot-very hot we all know what happens then....The ring would expand. Would there be a gap in the joint, especially of one of those pistons came down slightly before the other?In this photo of a wire ring welding machine look closely and you will notice there are two pistons that bring the electrodes down.Also notice that the beams they are mounted on are tied together in the area where the contacts are so thatthe both come down at the same time.Also notice that with a long beam that the contacts will strike perpendicular and not on an arc like yours.You really need to do your homework on something like this that has already been done for years.You could have just bought one of these machines.I would want a clamp on that ring. OR...See how one of the fixture blocks is on the inside of the ring, and two of them areon the outside. I would want all of them on the outside to keep the ring from expanding before the weld has fused.Like I said at the beginning all of this has already been figured out by people that make these rings .The thing that is wrong is expecting the tolerances given for something that is welded.A butt weld may not be the best design. If the ring ends were cut on an angle then the weld would be longer.Oh one more thing. Notice in the photo that the ring in the machine is NOT being held by a fixture.Just pointing out some of the finer points about metal expanding and contracting.Last edited by Donald Branscom; 06-16-2011 at 01:46 PM.AWS certified welding inspectorAWS certified welder
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Donald Branscom: I agree with you that we should be using a machine such as the one you show me. Point is, the price for the one we are using was less than 1k USD. We have a restriction set up by corporate regarding spending on machinery.Nonetheless, I can point them in such a direction. Were did you find this machine? Can you send me a link to their homepage?Appreciated
Reply:Rodrigo-I just selected a machine at random on the internet.I found it at:http://www.diytrade.com/china/4/prod...tt_welder.htmlBut there could be other choices based on size etc.Remember Rodrigo, you are not responsible for poor decisions by the management.If you make a suggestion to management to get a different machine they will ask you why the machine that you have does NOT work.You need to take a careful look at your machine and FIND OUT why it does not work.Watch the welding process with a welding helmet on and watch very closely to see if the weldment (ring) moves while being welded. Just really look close and pay attention to details. Try different welding settings and write them down.If it is a problem you cannot solve THEN you can tell management what the problem is and if it can be fixed or not.Good luck. And as they say.....Thats manufacturing!!Oh...Make sure to look at different machines and see what features are the same. There is a reason.Last edited by Donald Branscom; 06-16-2011 at 04:56 PM.AWS certified welding inspectorAWS certified welder
Reply:I was thinking about this and your welding problem.If the wire ring is in the fixture and the piston /contacts come down on the wire ring,the weld will expand slightly then contract. If it starts to contract/shrink and the contacts are still holding down the ring the ring could pull apart if the weld is still molten.Maybe the timing of the events is off.Observation: The ring in the Chinese machine is sticking out away from the machine NOT hanging downwards.That means that pressure is on that ring BEFORE the weld occurs.Last edited by Donald Branscom; 06-16-2011 at 05:22 PM.AWS certified welding inspectorAWS certified welderGoing out on a limb here.The washing process uses a soap and water bath to remove any dirt, the water thats being used is it from a local municipal water source, well, or is it purified water? If its the first two then would it be possible that the mineral content of the water is leaving residue on the wire causing this problem?Have you considered using acetone as a cleaner instead of a water soap bath? Is there any wipe down of the wire with sand paper or steel wool or scotch pads to remove any oxidation?Has the machine been checked for a stable output of power?How reliable is the electrical service in the facility?Any chance that the machine is sitting in a spot that gets a breeze?
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DonI agree with you regarding the timing on the process, will check this part of the welding if there is an issue.The different welding settings have already been tried. As I stated before (maybe I only mention it in passing- my mistake) we have already performed an experimental design based on welding amperage, clamp pressure, and annealing amperage. We found that the setting that give us the highest resistance output are the ones stated in the first post.@Big65moparMaybe a different solvent would be appropriate, but since the productions are around 4-5k pieces a shot, don't know if asking the operator to clean so many pieces would be health-wise. I don't think that I can use acetone in the machine I use to wash, since the bath container is made out of plastic and it would get eaten by it.Thanks for your thoughts, I'll modify a couple of things tomorrow and will let you know!
Reply:I'm assuming that the wire comes into your facility on large roles that are placed onto a stand and then one end is run into a puller to feed it into machine to make it into the slinky as you had stated earlier. Would it be possible to build a bath that would be placed between the wire spool and the machine so that the wire would be bathed in an acetone bath? I'm thinking maybe 5 foot long about a foot wide and foot deep with a roller bar a foot and half from either end with a grooved wheel for the wire to travel under in the bath and several brushes set up to rub the wire as it goes by to remove any loose debri and a covered top? Just thinking about possibilities for a hands off cleaning process.
Reply:Originally Posted by Rodrigo@DonI agree with you regarding the timing on the process, will check this part of the welding if there is an issue.The different welding settings have already been tried. As I stated before (maybe I only mention it in passing- my mistake) we have already performed an experimental design based on welding amperage, clamp pressure, and annealing amperage. We found that the setting that give us the highest resistance output are the ones stated in the first post.@Big65moparMaybe a different solvent would be appropriate, but since the productions are around 4-5k pieces a shot, don't know if asking the operator to clean so many pieces would be health-wise. I don't think that I can use acetone in the machine I use to wash, since the bath container is made out of plastic and it would get eaten by it.Thanks for your thoughts, I'll modify a couple of things tomorrow and will let you know!
Reply:is it possible that the cut is not always centered properly ? distance from the electrode to the cut must be equal to heat both sides the same.i dont see any mention of welding force(just clamping force ).
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boatbuoy: What do you mean by welding force? The stress that the weld must endure without breaking? If that's so, its around 24 kN.If you mean how much force is applied to maintain the ring in place while welding, then its 80 psi.@Don: I thought the same of acetone. I'm frustrated, but not enough to blow up the plant yet. Also, I don't think a water bath would be the best. Maybe an oil-based bath would work better.@Big65mopar: the idea of in-line cleaning sounds more than ok. Let me go to the drawing board and I'll come with an idea for it.Thanks guys, have a great weekend!Last edited by Rodrigo; 06-17-2011 at 05:55 PM.Reason: typo
Reply:by welding force,i meant the ends of the ring must be pushed toward each other to make the weld and this force is a critical weld factor.the amount of upset in the photo shows that force is applied.
Reply:Originally Posted by Rodrigo@Don: I thought the same of acetone. I'm frustrated, but not enough to blow up the plant yet. Also, I don't think a water bath would be the best. Maybe an oil-based bath would work better.@Big65mopar: the idea of in-line cleaning sounds more than ok. Let me go to the drawing board and I'll come with an idea for it.Thanks guys, have a great weekend!
Reply:automotive stampings are all coated with either a light oil or a drawing compound and are not washed or even wiped before resistance spot welding. never seems to cause a problem so i tend to doubt that its the problem here.
Reply:Wouldn't it depend on the type of oil used as to whether it would cause problems with the weld?Welding Supervisor Department of Corrections.
Reply:Originally Posted by Big65moparWouldn't it depend on the type of oil used as to whether it would cause problems with the weld?
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ossibilities with the oil coating could be that itself was contaminated prior to the coating application. I'm wondering though if there might be an issue with either the machines power supply, buildings electrical service or the power grid feeding the building that's causing noise in the machine affecting the process. In the past when I was installing dbs systems in residential and commercial settings I had run into instances where the wiring was so old in a home that it would causing signal issues through the receiver ( cloth wrapped wiring from the 1930's ). I had also ran into situations where additions onto a structure was done and tied into the existing breaker box and added to the structures grid along with two basement offices and added low voltage lighting throughout and every time a refrigerator would come on it would shut down the receiver and send the television into a hippy dream of psychedelic patterns and colors because the breaker box was overloaded and causing the all sorts of failures in fixtures and appliances in the structure. A tv that has been damaged by a power surge from a black out and restart of power to the house can output enough voltage into the coax grid in a neighborhood that it will disrupt television, telephone and internet service within two city blocks on every address thats on that node and amp.Welding Supervisor Department of Corrections.
Reply:Thanks for the replies and suggestions guys.@boatbuoy: yep, the raw material is usually covered in soap, which is removed and then dried on a centrifuge machine. Therefore, the material arrives at the line dry and clean. Also, I agree with you, if it were an oil or surface coverage issue, it would be a 100% issue, and we have around 50 ppm.@Big65mopar: We are already checking the power grid that feeds this machine. I'll let you know if we come out with something.,Last edited by Rodrigo; 06-20-2011 at 01:26 PM.Reason: typo
