Weaving more then 3 times the rod dia?

By jon20013 (*****)

Date 02-25-2005 10:39

Each welder has their own preferences, but the bottom line is you will likely have a welding procedure or some other program document that limits you to no more than 3x the electrode diameter; this is an extremely common restriction from my experience and, while your weld may be good as gold structurally and have sufficient mechanical integrity, if you don't follow your welding procedure or other controlling programs you're weld will get rejected. One reason for this restriction is you place an awful lot more heat input into your joint doing wide weaves (obviously your travel speed is slower doing wider weaves) and this high heat input is one of the things engineers and inspectors are concerned with... more heat, more metal carried, more mechanical stresses induced. Hope that helps you understand a bit better.

By jon20013 (*****)

Date 02-25-2005 10:54

Sorry, wanted to carry this a bit further; there are other issues which can occur, especially when welding stainless steel: the higher heat input can ultimately lead to degredation of the stainless steel while inservice. Your weld may look pretty good when you've finished it but metallurgically you may have boned the piece, excessive heat input on stainless can lead to intergranular cracking and accellerate corrosion (yes, 300 series stainless will rust and corrode!) there are a whole host of other metallurgical reasons to limit the size of your weld beads.

By metalcare (*)

Date 02-25-2005 13:52

We had carriedout an extensive study on this subject while developing procedure qualifications. In carbon steel , excess weaving would severely degrade the weld metal impact properties, which is the primary reason why excessive weaving is not permitted. The weld with excessive weaving appears to be with nice, uniform and appealing weld profile but its impact strength would be much lower compared to stringer bead. The impact property is considered extremely important especially on low temperature environments.

In Stainless steel, higher heat inputs lead to carbide precitipation, which could be a source for strees corosion cracking/degradation in impact property (Impact property could be affected by the formation of hard and brittle chromium carbides)

Usually, either stringer or weave bead should be specified in the WPS by the welding engineer. In case of weave bead, it should also specify how much weaving is permitted.

Any comments appreciated.
Muthu

By pipewelder_1999 (****)

Date 02-25-2005 22:24

Wouldn't the speed of travel have more to do with heat input then the widt of the weave?

I can run a "thick narrow" bead filling a groove and put more heat into the base metal than when capping. I know that this has happened just by the amount the pipe glows when filling as opposed to capping.

The amount of heat put into a given weld is more related to the volume of metal deposited in a given length than it is the width. Depending upon the technique and pass thickness, bead width could or could not affect impact values. YES most often it does .

The variable to control while welding would be "HEAT INPUT" and not weave width. Heat input is more directly related and is often the related to bead width but NOT always.

Have a nice day

Gerald Austin

By metalcare (*)

Date 02-26-2005 00:16

Gerald:
I agree with your analogy. Everything is to do with the heat input. From my observation in general, welders usually have tendency to weld in slower welding speed while weaving than stringer; unless the welder delibrately slows down while making stringer runs.

Muthu

By - Date 03-23-2005 21:23

Gerald,
Heat input (J) is determined by multiplying the V X A X 60 divided by the travel speed. I.E., H=60AV/S. For example if you are using a stainless steel FCW and your V=28, and your A=190, and your travel speed is 16 IPM. Your heat input will be 19950 J/min. So, travel speed is directly proportional to whether you are weaving or running beads. The slower the travel speed the higher the heat input (J). Therefore, heat input has a tremendous effect on the integrity of a stainless weld.

CM

By pipewelder_1999 (****)

Date 03-23-2005 21:59

I understand the heat input formula however it is related to a forward travel speed. The oscillation that occurs during that forward travel may or may not result in a significant change in forward travel.

I can weave the electrode in varying degrees and still maintain a given travel speed. That was my point.

Isn't the actual heat input also based upon certain processes? The GENERAL rule is as indicated above but if you get into the details, aren't certain processes more efficient at depositing energy into a weld ? I have always wanted to pick a welding engineers brain so forgive me for asking more stuff on an already lengthy topic.

Thanks for your input on this topic

Gerald Austin

By - Date 03-23-2005 22:27

Gerald, where do you find that heat input is only regarding forward progression? How would you measure heat input for a downhill weld? With all due respect, oscillation is not considered a "technique", but more a welding preference. As you already know, oscillation may or may not affect the travel speed, but in general terms, it usually does. Heat input and the formula for figuring it applies to all processes. The difference is that certain processes have different allowable Joules (heat input restrictions). Using the TIG process on a Schedule 10 pipe will have a lower J than a FCW weld on a schedule 80 flange. Usually, but not always, the Welding Engineer will have J ranges for the welding process incorporated. When welding stainless steel, we can usually put aside what and how we weld carbon steel. The metallurgical makeup is totally different and the welding is also different. I mean, welding is welding, but different techniques, heat inputs, interpass temperatures, etc. apply to stainless welding than apply to carbon steel welding.

CM

By pipewelder_1999 (****)

Date 03-24-2005 03:36

Are you saying that 40Kj of energy into a piece of material is different than 40Kj of GTAW or that with an equal amperage/voltage/travel speed each process puts in different amounts of energy ?

If the travel speed is NOT in reference to a path of progression (forward) then is it related to the actual velocity of the arc travel regardless of the direction in relationship to the progression of the actual bead ?

I understand the different effects of heat input between the two material types and how the base metal thickess can affect the ability to absorb energy however I think that restricting weaving as opposed to actual heat input is just a simple way for people to get a warm fuzzy feeling that they are doing a good thing when they may be overlooking the actual variables that may be detrimental.

Amperage, voltage, base metal thickness, preheat/interpass, shielding gas etc all control how long a piece of SS stays at a critical temperature but the width of the bead has less to do with this unless the other variables are monitored.

An example would be SMAW welding. Electrode meltoff/usage in a given length of weld would be more indicative of the amount of energy put into a given length than would the width of the bead.

Thanks

Gerald Austin

By chall

Date 03-24-2005 13:36

The formula only considers current, voltage and (forward) travel speed. There is no consideration given to process or shielding gas. It is known that certain processes and gases elevate the heat at the arc. However, the practical response to that is to adjust the settings to a point that an acceptable weld may be performed. (I know I'm preaching to an experienced group of welders, I'm just trying to lay it out the way it chuggs through my admittedly slow brain.)

Using the same set of electrical parameters, a wide weave deposits more heat due to slowing of the forward progress. However, if you you are competent at this technique, maybe you would set your parameters such that while you weave, you either have a lower product of voltage and current (which compensates for a slower TS); or you can actually weave fast and travel speed is negligibly changed.

I think from the standpoint of an inspector who has never welded, we look at the bead width and make an assumption that the weld was done with slower forward progress, thus more heat input. It's not an absolute, it's just one way to do QC after the weld is completed, rather than monitoring the weld in progress. This is only valid for comparing the actual weave width to the WPS limit on weave width.

Speaking from personal experience, when we write a wps, whether or not heat input is a concern for the procedure, we usually limit weave width to 2-1/2 times electrode diameter. That requirement was imposed on us years ago when we were the maintenance group at a nuclear plant and it has remained in our mindset since then.

Charles

By - Date 03-24-2005 14:22

I agree... Heat input is measured as such: J=60AV/S. Where does it say heat input can only be measured in the forward progression? Heat input, as we all know, applies to each welding process without prejudice.

CM

By - Date 03-24-2005 15:46

Charles,

While I agree with virtually all you say (for what that's worth <smile>) I would respectfully like to point out one thing. Regarding your last paragraph about whether heat input is a concern when qualifying a procedure, the heat input should be a major concern depending on the grade of stainless you are welding. Heat input affects different grades in different ways. Neglecting the heat input can affect corrosion resistance and mechanical properties if not adjusted for the grade of stainless you are welding.

CM

By chall

Date 03-24-2005 16:42

This is turning into a good learning opportunity for me. What I meant by my statement is that on some projects not involving systems subject to notch toughness requirements, we don't closely monitor the actual parameters the welder uses. When notch toughness is called out, we usually spend time before the project starts briefing and training the welders involved, and closely monitor welding in the field.

It sounds like you may be suggesting that all welds should be stictly performed to avoid impacting mechanical & corrosion resistance properties (for stainless).

I've had some PQRs done in an effort to qualify WPSs that were run as hot as the welder could handle. In some cases we've had heat input approaching 60kj/in. In my estimation it would have been difficult to heat the material any more and still be able to deposit an acceptable weld. We did this to give ourselves the maximum range of parameters for field welding to be accomplished by welders of varying abilities. These procedures (on API 5L piping materials) held up to the notch toughness requirements. Corrosion resistance wasn't among the properties closely considered.

As for stainless. We've only done a couple of procdures that were impact tested. At -325F the toughness values were almost all off the chart high, so I am a bit dubious about the "real" impact of running "hot". I recall those PQRs deposited between 30 & 40 kj/in.

I admit that my knowledge about stainless is fundemental, but I thought that if the chromium depleted layer (resulting from the heat of welding) was removed, passivation would occur and corrosion resistance would be restored. I know that polishing and pickling improve corrosion resistance, but it seems like you are suggesting that there is more to it than just restoring the passive layer of chromium oxide that forms by itself (or can be assited with the application of passivation or pickling chemicals).

Thanks for taking the time to shed some light on this topic.
Charles

By - Date 03-24-2005 17:44

Hi Charles,
This does seem like it is turning ito a marathon on welding stainless steel. My line of expertise (if there is such a thing for me) is strictly stainless steel. Your points are very well taken,but since we are on a marathon discussion, let's go one step further. Strict "monitoring" of every welder is not always possible, that's why every welder should follow the parameters on the WPS, which was proven to be acceptable by the PQR. In my opinion, the parameters of the weld should not be left up to the descretion of the welder especially when welding stainless steel. Notch toughness is only one in a series of things that affect the suitability of stainless to the medium it is being subjected to. Respectfully, I'm not only suggesting that all stainless welds be performed to avoid impacting mechanical and corrosion resistance, but think it is an absolute necessity. Why else would a customer spec a stainless steel if he wasn't concerned about the mechanicals and corrosion resistance? If a customer is not concerned with them, save a lot of money and spec carbon steel. 60kj/in is not that high of a heat input if the material is thick enough to withstand the heat. At -325 deg. F., or cryogenic service temperature, well, that is another story. Section VIII of the ASME Boiler and Pressure Code requires Charpy V-notch testing, but the criterion for acceptability is that the samples attain a lateral expansion opposite the notch of no less than 15 mils (0.38mm) for each of the three specimens. One of the many disadvantages of running "hot" is the loss of alloying elements in the weld arc. Another is the alteration of the phase balance of both the filler metal and the HAZ of the parent metal. You are certainly right about removing the oxide layer to let the stainless steel restore the chromium layer, but running too hot can also affect the thickness of the oxide layer. To assume that one heat range is suitable for all stainless steel is not a good assumption. (I know you're not saying that). The ferrite content of a 316, for example, reacts differently than a 310 when exposed to a high heat input. Running too hot can cause accelerated metal fatigue and embrittlement. Not a whole lot of good is accomlished when a stainless steel is used beyond it's intended limits.
Well, I've gone on enough to the point that I hope it is not boring you.

CM

By - Date 03-24-2005 15:28

Hi Gerald,
This discussion is really getting into details. In response to your first sentence....I'm only saying that generally GTAW has a lower heat input because of lower volts and amps (travel speed included). Lets say that a welder does a heat calculation using the GTAW process and the heat input is calculated to be 40J. If that same welder uses the exact same volts, amps, and travel speed, the heat input will still be 40J for any other process. A PhD collegue, a graduate Welding Engineer from Ohio State University, just told me on a telephone conversation that heat input calculations are not restricted to only "forward" pregression. I, too, am a Welding Engineer dealing only in stainless steel and I could not find any literature that restricted heat input calculations to only the forward progression.
Your 4th paragraph regarding amperage, volts, base metal thickness....We may be saying the same thing, but the width of the bead is directly proportional to the travel speed. Heat input ONLY involves volts, amps, and travel speed, nothing else. Also, "critical" temperatures of stainless steel are relative to the grade of stainless. A Duplex material (2205) can start forming sigma in a matter of one minute at elevated temperatures, while a pure austenitic material (625) is virtually immune to sigma. But, you are right in saying all the variables you listed can determine how long a stainless steel remains at temperature, with shielding gas being the very least determining factor.

CM

By pipewelder_1999 (****)

Date 03-24-2005 18:33

When I was speaking of progression it was not in reference to uphill/downhill, forehand,backhand etc. It was related to whether from point a to point b was travelled in a straight line or a weaving motion. If the time it takes to get there is 20 seconds for either method, the heat input is the same.

GA

By - Date 03-24-2005 18:44

GA,
I see.. I guess I took it literally when you said a "forward progression". So I assume you were referring to a bead type progression as opposed to a weave type progression. Makes sense to me. Thank you..

CM

By pipewelder_1999 (****)

Date 03-24-2005 19:53

I still appreciate the input.

By - Date 03-24-2005 20:33

I appreciate it, too. Some great information is being shared.

CM

By ssbn727 (*****)

Date 03-26-2005 08:40

Hey Cmeadows, Gerald!
I appreciate this thread also!!! So much so, that I'm going to show this to my boss!!! Maybe then he'll get off my butt for taking too long on my welds... I wait until the interpass temp is below 350F while welding 316L in order to continue, and he keeps bugging me about me slacking off... Yeah right!!! Hey Chall! For someone who's not a welder, you sure could've fooled me with your understanding of welding technique friend!!!
Gerald! Hows the leg doing? Always good to read your explanations!!! Hey Cmeadows! In case my "jefe" needs to contact you, please send me an e-mail. hanklive39@hotmail.com

Respectfully,
SSBN727
Run Silent... Run Deep!!!

By pipewelder_1999 (****)

Date 03-26-2005 12:19

Hey SSBN

My leg is doing good. Skated some yesterday.

By ssbn727 (*****)

Date 03-31-2005 07:12

Hey Gerald!!!
Glad to hear it!! All the best to you!!!
I hear there's a whole bunch of work happening near your neck of the woods via the shipyards... I hear a whole lot of welding is going to be required on some new construction USN work... I believe Ameri-force is recruiting pipe & structural welders, and other shipyard tradescraft for Mississippi & Louisiana.

If you have any contacts besides the above mentioned agency, please e-mail me so I could pass them along to a friend who's thinking of relocating to your neck of the woods. I'd appreciate what you could come up with Gerald. hanklive39@hotmail.com

Respectfully,
SSBN727
Run Silent... Run Deep!!!

By - Date 03-26-2005 14:05

Hi SSBN727,
chuck.meadows@outokumpu.com
I work for a company out of Avesta, Sweden and we are the 2nd largest producer of stainless steel welding consumables in the world. All I deal in is stainless steel, so I think I can show your boss where it is advisable to let stainless steel cool below 350F. (actually, it's below 300F. or 150C.) before continuing. This temperature is ignored a lot, but it is still the "recommended" interpass temperature.

Chuck

By ssbn727 (*****)

Date 03-31-2005 06:58

Hi Cmeadows!
Thanks for your reply Chuck!
We already use Avesta Polarit-er I mean, Outotkumpu as our filler metal, and I personally prefer it over other brands also for most stainless applications... I've already got your website in my favorites and have referred many of my colleagues to the website for technical info, including my current superior (plant manager) - who upon studying your website recently, has now changed his attitude completely regarding the production time he previously thought he was losing due to waiting for the interpass temperature to come down to recommended levels.
I also wait until 300F to continue but, My superior "thinks" or is led to believe that I only wait until 350F (the welders carry both temperature crayons) just so I can get him off my (I'm the welding supervisor) and every other welder's back!!! He keeps saying to me: "They do'nt wait in Germany when they weld these together, why should we?" Hey, I like this current "gig" because, it's only four blocks away from where I currently reside so, I politely referred him to the website in order to avoid a confrontation with him, and "Voila"!!! Presto!!!180 degree change in his attitude towards the welding shop as a whole...
A funny thing about Germany is the fact that they do not use temperature crayons to monitor interpass temps even though they're welding with a slightly different base & filler metal, 316Ti... As I understand it, this stainless grade which is'nt produced in the US, and is'nt listed in ASME section IX's base metal groups is exclusive to Europe so, that's why we currently use 316L for systems sold in use where ASME section IX is being applied ... In fact, I do'nt believe they monitor interpass temps at all with 316Ti which to me is ludicrus but, then again I've only been working with a wide variety of stainless steels applied to many standards on and off for approximately 25 plus years, and have been welding and fabricating for over thirty... What do I know???
Oh-Well, different strokes for different folks!!!

Being close to fifty years young now(Who says I'm getting OLD!!!), I do'nt have the memory recall that I was once blessed with when I was much younger in age so, correct me if I'm inaccurate about 316Ti regarding whether or not this grade also requires a 300F interpass temp to be monitored for producing sound welds with this grade of stainless which I believe I read as a "recommendation" in the Outokumpu website? Oh yeah, It's an excellent website and the products are too!!!

Btw, Is there any significant meaning to the name change from Avesta-Polarit to Outokumpu, and what does Outokumpu mean, may I ask?

Anywho, many thanks for your help because, my "jefe" also read your reply here Chuck so, I believe he's getting a much needed education!!! P.S. Germany is also second guessing themselves as a result!!! What can I say!!! "Everywhere I go - trouble follows me because, I certainly do'nt look for it or - maybe I do???"

Respectfully,
SSBN727
Run Silent... Run Deep!!!

By - Date 03-31-2005 13:34

Hello My Friend,
Thanks for the great e-mail !! I'm glad you are happy with the Avesta brand of filler metals. I guess being the Welding Engineer here in the USA for them, I'm a little prejudice towards our products. But, I consider them one of the best, if not the best, stainless steel welding consumables there are. Again, thank you.
It is still important, even though it is often violated, to maintain an interpass temp. of 300 deg. F. for all stainess steels, including 316Ti. The only exception is the interpass temp. for 2507 Super Dupex, where is is recommended at 200 F.
Now about the name change...AvestaPolarit (Avesta Sheffield) merged with Outokumpu (which was primarily a copper manufacturer but also stainless steel) to enhance both companys productivity and become either the world's largest or 2nd larges producer of stainless steel. As you know, Avesta was a Swedish company and Outokumpu is a Finnish company. Now, we are one. But, to make things a little more confusing, upon the merger it was decided to maintain the Avesta Welding name because it is too well known to change to Outokumpu Welding. So, the welding division kept our original name. The word Outokumpu means "fertile hill" because of the original discovery of copper there. Boy, what a history lesson. <smile>
Again, it was great to read your e-mail. Please keep in touch if there is anything I can help you with regarding your stainless steel concerns. Have a great day !!! Thanks again...

Chuck

By GRoberts (***)

Date 03-23-2005 23:41

Gerald,
I don't see much compensation on this side of the pond for different processes in heat input formulas, but in Europe, it seems to be common practice to use multiplying factors for each process, as you mentioned, based on their efficiency of transfering heat to the base metal. I don't remember what they are off the top of my head, but I know GTAW is one of the least efficient. SAW is very high, followed by FCAW/GMAW, then SMAW.

By - Date 03-24-2005 00:14

Hi Gerald,
I'm probably mis-reading, or misinterpreting something, but all welding process you mentioned use the same formula for determining heat input. You are certainly right (I think) about the processes that transfer the arc energy (moreso than heat transfer). Just one thing....When using the GMAW process, the shielding gas can definitely affect the arc energy. Argon (atomic weight of 40) will have less arc energy than helium (atomic weight of 4), for an example, because of the less resistance through the arc when using a helium based shielding gas.

CM

By - Date 06-29-2005 17:27

Gerald, will you please contact me at my e-mail address?

chuck.meadows@outokumpu.com

Thanks, I need to ask you something.

Chuck

By pipewelder_1999 (****)

Date 06-29-2005 19:22

Done

By pipewelder_1999 (****)

Date 02-25-2005 22:29

There is NO rule of thumb that applies everywhere. Sometimes the rules laid down are the result of welding wives tales, specs from a previous job, what grandpa used to doi, etc . Sometimes the actual project requirements and specificatios will restrict weaving or heat input based on service etc.

The actual effects of your described technique in MY OPINION are nothing. The slip on flange is a big heat sink and therefore absorbs most of the enrgy

By Lawrence (*****)

Date 02-26-2005 13:48

C'mon Gerald,

There are plenty of "rules of thumb"

The thing is, we also must consider the FACT that;
There are an infinite number of variables and ways a person can screw something up :)

By pipewelder_1999 (****)

Date 02-26-2005 19:01

Yes plenty of rules of thumb, its just that sometimes we have a messed up thumb !

By dasimonds (**)

Date 02-26-2005 18:06

It seems to me that it is application dependent.
Is this a multi-pass fillet with a single bead cap, or a 1 pass 5/8" fillet?
Is the weld for something ornamental at home, or some code work?
Is it an "L" grade stainless?
Is the weld 2G, 5G or 6G?
What does the ID of the pipe look like after welding?
What kind of service environment is the pipe going to see? Something corrosive and considered "lethal service", or a water line?
How much pressure will the line operate at?
Does the customer require charpy values?
The fact that you got hollared for not running 2 stringers at says a lot.
I don't know if it makes any difference to you or not, but these are the kind of things I like to know about, BEFORE I start welding. I'm not trying to beat up on you or anything, as I don't know what kind of welder you are.
Realistically, we have all seen the welds with the huge weaves, that no one in his right mind would put his number on, that function without a problem for all their intended lives.
I don't think I have ever worked with an inspector that was competent at his job that would let the weld fly.
In the end, I guess , like all welders, you have to let your consceince be your guide.
Hope this helps,
Dale Simonds

By olmpkwelder474 (*)

Date 02-27-2005 00:48

I t was a multipass fillet done in the 5 F position on pipe stands. Remember i stated the thickness of the pipe a bit more then 3/8" so carbide precip is kind of out of the question unless u don't have a clue of whats goin on and ur welding at 300 amps. Oh yeah it's a 304 stainless base matl and using a 316L filler. I don't know the code we're welding too i just go buy what i see on the other flanges and what everyone else is doing and tweek it a bit. I made the weld in 3 passes and the third pass i made the next day quartering the pipe on each pass.
This pipe is an oil line to an oil cooler off a gas turbine generator. The pipes are usually visualy inspected and these particular pipes were PT'D and they all passed. I'm also waxin the cup up the sides of the pipe and flange so i'm cooking pretty good and don't really put a lot of heat into the part and i mean come on a 300 pound flange is over 3" thick so it does soak up some heat.
I've been tought in inspection classes and in college that ur not suppose to weave more then 3 times the rod diam, but it's done allmost everywhere and i do it all the time and i will allways do it. If it calls for a 1/2'' or 5/8'' fillet on a flange using 7018 i'm gonna grab a 1/8'' rod and weld it up. I guarantee you put just as much or close to the amount of heat into the part with a 5/32'' rod as you would with a 1/8'' while u lay a slick weld in there. Slick lookin welds take precision and time.
And the impact resistence on this particular part or any other pipe i weld shouldn't really be a key factor i'm thinking. These pipes are bolted to many other pipes and supported everywhere even in places where u'd be like why the heck do they want a support here.he he
Would a pipe that was welded hot and allowed to cool slow be more ductile then a pipe thats was welded cold and allowed to cool slow? I am under the impression the hot one would be more ductile. Would that be what u want in a pipe that moves around a lot? Thats if u do it right i know there is more imformation needed to answer that properly, but lets just say it was done with out all the bad things happening.lol Also i've never seen any weld procedure state how wide to weave ur weld and what size rod to use in the work i'm doing. I know on some jobs and some fields it will get down to the nats ass, but this stuff i'm doing isn't going on the space shuttle.
Thanks for all the responce!!

By ssbn727 (*****)

Date 02-27-2005 10:51

Hey olmpkwelder 474!

JW steered me back here into this thread so I would'nt miss out on the rest of this conversation.

Anywho, sounds like you've welded more carbon steel pipe than stainless.. Maybe I'm incorrect. In any case, I would find out the code or standard that applies in your situation. (sounds like ASME B31.3?) and the WPS before starting to weld the joint any which way you want to - especially on stainless, even if the flanges are 3" thick. Now, if you did this and there was'nt any mention of the use of stringers only, or the bead width had to conform to however many times the diameter of the electrode, or there was'nt any detailed view of the weld sequence whereby the cover clearly indicates more than one bead, then it would be difficult to argue against your point of view regarding the use of such a wide bead. I've been in situations where just the opposite occurred whereby a wide single weave bead was required as a cover and I knew that if I was to do this, I would be applying too much heat input resulting in a very wide HAZ which is very important to control and keep to a minimum when working with stainless. What did I do? I simply welded two stringers (at the low end of the parameters with plenty enough filler) then autogenously fused the two together with minimal heat input. avoiding the possibility of carbide percipitation, SCC (Stress Corrosion Cracking) or sensitization.
Sure it took longer, but I felt good that there was'nt a huge HAZ and the weld passed VT, then RT or UT without any problems.

Why not use a 308L filler for the joint? Is the 300# flange a 316/316L type or is both the pipe and flange 304?

I've heard of "walking the cup" but, I've never heard of "waxing the cup"...:)

BTW, "slick looking" welds does'nt automatically mean sound welds especially for stainless steel... I've seen a fair share of "slick looking" welds fail mechanicals or RT/UT because certain parameters were'nt followed.

Anywho, good luck and review the WPS carefully...:)

Respectfully,
SSBN727 Run Silent... Run Deep!!!

By jon20013 (*****)

Date 02-28-2005 10:54

Well, I may be making a large assumption here but, if the poster got yelled at for putting too large of weave then there must have been a WPS or specification restriction. And yes, I was talking in very general terms Gerald re wide weave is "usually" run much slower by the welder thereby creating a higher heat input. Often the only way one can respond to some of the questions here in the Forum is by speaking in generalilities.

By Jim Hughes (***)

Date 02-28-2005 19:16

I would agree with Mr. SS6N727. A good look at the WPS is in order. It's all about how they qualified their procedures. I have seen them with 4.5 times the rod diameter before. Also since your using a LGL with a #12 cup, what is the color of the weld when you break your arc? If it's Silver, Gold, or a light blue-ish I would say your travel speed and heat input are very close, (a heat input calc. would be great if there is someone who can do it) if it's purple or black you need to be checking your interpass temp. Most L grade S.S WPS's that I have seen is 350 F max. Hope this helps.
JPH

By pipewelder_1999 (****)

Date 02-28-2005 21:26

I kinda figured you were . Lots a variables here but it sounds to me like they're are putting restrictions on where not needed but I'm not there.

Have a good one Jon

GA

By dasimonds (**)

Date 03-01-2005 03:32

I'm not exactly sure what you mean by that, BUT, where do you draw the line? Really, isn't that where the WPQR's and WPS's come into play? What place do we really have for "I'll do it how ever I want"? Maybe an acceptable attitude for A-36 or the like.
What about a critical application? The kind that might be termed "lethal service"? "I"ll do whatever I want" be OK there?
The whole point to this thread is "can I do what I want"? Really, a 5/8" fillet with 1/8" wire in 3 passes with GTAW? Come on.! Never mind the fact that were dealing with an non "L" grade material. If this were an FCAW or SMAW weld, I personally would be looking at between 6 and 10 passes.
What company or corporation would enter into a contract with another on the basis that "our tests were successful, but our guys weld however they think is best". Can you see this guy in a nuke plant? How long do you think he'd be there?
Think about it.
The "do what you want" program is for raking leaves, mowing lawns, and baiting your hook. We have guidelines for welding!
I'm sorry if the answer is NO!
DaleSimonds

By pipewelder_1999 (****)

Date 03-01-2005 14:46

I never condoned working outside the range of the WPS or any engineering restrictions.

BUT what basis does an inspector have to restrict this if its not on the wps or project specifications? In my opinion, ABSOLUTELY NONE.

If there is an engineering reason to restrict heat input then do that. But restrict the heat input. This is done based on travel speed, amps, volts, and the welding process.

I agree that there are base materials and service conditions that warrant basic controls but also much of this stuff is NOT rocket science. We should stick to the facts, the specifications , and let the engineers decide what those are. If no guidlines exist, find out. But don't decide something is wrong because it was that way on the last job. Each case in unique and should be addressed as such.

Of course that too is an opinion.

GA

By jon20013 (*****)

Date 03-01-2005 18:19

Okay, one last statement on this subject to olmpkwelder474; when all else fails, POLITELY as "them" to show you where the requirement comes from so you might further your own understanding, or possibly flush out someone's "opinion" versus a "requirement."

By jon20013 (*****)

Date 03-01-2005 11:09

Well, I think as someone wisely pointed out in the Forum once before, it's very difficult to determine the 3x weave restriction because it's actually regarding the tungsten travel, not the size of the finished bead. Nuff said from this side.

By rodofgod (**)

Date 03-02-2005 11:03

Hi All!

Very interesting subject!

As a welder, I know how easy it is to ‘ignore’ or disregard weave restrictions on a WPS! Quicker the better!

Who decided the maximum weave width?

What reasons for a maximum weave width?

How can a weave restriction alter the weld?

However, as a Welding Inspector, with a ‘basic’ knowledge of metallurgy, I can understand the concern expressed by olmpkwelder474’s inspector!

Overhear, in the U.K., we have what is known as ‘Good Engineering Practices’, It’s not laid down in any code or whatever, however, many Inspectors require the ‘client’ to adhere to these requirements, and as a rule, they work well!
Weaving more than 2.5X the electrode diameter is considered BAD practice!
How this works when using M.I.G./F.C.A.W. is 12mm max. weave for a 1.2MM wire!

Weave width is always going to be a controversial with Welders and Inspectors alike. Many WPS’s do not stipulate weave restrictions, however, most have some say as regards heat input etc. Weave width restrictions are, in my opinion, an old fashioned way of regulating heat input. It’s not an exact science! Thickness of weld deposit, speed of travel, arc volts etc all have a say!
Also, one has to consider dilution of weld metal, and any ‘mechanical’ requirements of the final weldment.
It’s common over here on refineries etc. for a minimum of two capping runs to be visible on socket welds, fillet welds, regardless of size.

Using 316 wire for welding 304 parent metal seems strange to me!

Regards

By Jim Hughes (***)

Date 03-03-2005 22:26

Why is it considered bad practice?

By olmpkwelder474 (*)

Date 03-04-2005 00:57

Well, just to add some more info to this subject to help u guys out a bit more i'll ad a few more things. It was not an inspector who barked at myself it was a fellow fitter. There is no WPS to welding flanges out here so i was going but the old rule of thumb put as big a fillet as the smallest member being welded to and looking at whats on the rest of the flanges. If u were to bust out a fillet weld guage on the weld i made it was probably more around 1/2'' or so. The face of the fillet was more around 5/8'' wide. The color of the weld when i was done was blue and gold. No color outside of the weld to show a heat affected zone so it didn't get that hot,and again i'm scootin up the side of this pipe. I don't know i mean were tig welding 1/2'' stainless pipe with no remote so when u brake an arc on top u have to run out of it real fast or pull away and put the gas back on it real quick, but the stuff contaminates instantly and i try to tell em it's no use puting the gas back on there cause as soon as they pull away it turns black. So what kind of standard does that go under. On big stuff u can get away witout a remote if u know what ur doing but that 1/2'' stainless pipe with no remote your just gona be breaking all the rules. These guys have been doing it for years so i guess the pipes have been holding up ok.

By Lawrence (*****)

Date 03-04-2005 01:17

Heh,

Reminds me of my first gig with a mechanical contractor after being discharged from the Navy. I was all pumped up with my hand full of exotic thin metal certs on that first interview. They took me back into the fab shop and were nice enough to even provide a fitted 3" schedule 5 joint to brewmaster. After taking a look at the antique power source (an R2D2) I asked the forman where the foot pedal was...

The whole shop roared.

Thankfully that old lead man took me under his wing anyhow.

By Jim Hughes (***)

Date 03-05-2005 01:19

I still think it is inportant to see what your P8 to P8 WPS says. The blue gold indicates good travel and heat input. COLOR MAKES A DIFFERENCE I just left a fab shop where we did 800.000 to 1 million in capital work each year. 90% of our work was SCH 10 304L and 316L S.S. The welders in this shop which I was one of them could not brush the weld, the inspector wanted to see the color. Gold was good. Now I have moved into the engineering field and I'm on a job(northwest) where we are welding 2" and 3" Sch 40 304L S.S and these guys are using reg. collet body and no gas lens and there welds are black and they think there fine. So I said all that to say this, sounds like you know what your doing, and it sound like a little jealousy on the person that ragged on you about it. I would hire you in a heart beat.

By rodofgod (**)

Date 03-07-2005 02:05

Hi jim!
this is considered "bad practice" because of the possibility that a given practice will alter a WPS so as to affect that WPS, outside it's parameters! Whilst still being within the procedure, itself!
Sounds complicated,I know! But it does work!

By Jim Hughes (***)

Date 03-07-2005 02:44

I disagree. Who said it is considered bad practice? I'm looking at a WPS right now that has been qualified to Sec. IX that says in the tech. block Bead Type: stringer or weave Weave 3.5 times diam. We opperated under our qualified procedures. The welders had access to these procedures. Granted the person that put the posting up needs to find out what their procedure says. If in fact their WPS says stringers only then the welders in that shop need to abide by them. I think we need to be careful about making a blanket statement that it's "brad practice".
I appreciate your input though.