AWS D1.1- Max Interpass Temperature

By Nanjing Date 12-29-2009 11:09

Depends on material you are welding, what is it Q+T for instance?

By eekpod

Date 12-30-2009 11:24

250 degree CELCIUS?? Wow that's hot. Maybe it should be Farenheit, that's most likely what they mean.

By 3.2 Inspector (***)

Date 12-30-2009 15:35

That is a normal temp. maybe even a bit on the cold side :)

3.2

By swnorris (****)

Date 12-30-2009 17:37

D1.1 does not address the maximum interpass temperature. We typically use 550 degrees F.

Two good articles:

Importance of Interpass Temperature

http://www.jflf.org/pdfs/papers/keyconcepts3.pdf

Taking your Welds Temperature

http://www.aisc.org/ContentManagement/ContentDisplay.cfm?ContentID=512

Also,

http://www.mwsco.com/kb/kb_frameset.asp?ArticleID=73

By Nalla

Date 01-01-2010 12:10

Dear Friends
Mat. 25.4mm thk x EH36.-Group II Material.
Working Code - AWS D1.1
These WPS/PQR Qualified by X-Senior QA Guys. Most of the WPS Indicate Max. Interpass Temp. as 250 deg. celcius.
To my best of my knowledge, all parameters/ranges shall be in accordance with respective code.

Appreciate all contribution but I still dont understand the logic of this Max. Temp.

Happy New Year Wishes to ALL Forum Members.

By waccobird (****)

Date 01-01-2010 12:41

Nalla
It is kind of high to my wps's. But it would allow the welder to produce more weld more quickly, not requiring as much time between passes.
The welder doesn't have to maintain 250 degrees Celcius, that is the max temp of the weld area that they can apply the next weld layer to.
As Scott's last link on his post reads
American Welding Society Position Statement on the Northridge Earthquake recommends that interpass temperature not exceed 550 F when notch toughness is a requirement.
There are other times when a designer may want to limit the maximum interpass temperature. For example, if he expects a minimum strength level for a particular component that could experience extremely high interpass temperatures, due to its size or welding procedures, he would specify a maximum interpass temperature. Otherwise, weld strength may be unacceptably low. A maximum interpass temperature is also necessary for quenched and tempered steels. Due to their heattreating characteristics, engineers must control interpass temperature within limits in order to provide adequate mechanical properties in the weld metal and HAZ.

Maximum interpass temperature control is not always required. In fact, AWS D1.1 does not impose such control
Hope this helps more than hurts
Marshall

By welderbrent (*****)

Date 01-04-2010 00:06 Edited 01-04-2010 00:10

Okay, I know I just got back in town from the holidays, SO, I hope I am following this right, If not- just shoot me.

In line with what Scott and Marshall have stated, I believe you are dealing with 'MAX' interpass temps. Not sure I would want it to actually hit that very often (personal opinion). BUT, I also think what you 'COULD' be dealing with is the added qualifiers from D1.8 Seismic Supplement. In Clause 6.5 'Maximum Interpass Temperature' under 6.5.1 "The maximum interpass temperature shall not exceed 550*F (300*C), unless an alternate value is qualified in accordance with 6.5.2."

Thus, if you are required to meet Seismic Code, or your company just chooses to meet these more restrictive requirements, then this may be where those numbers have come from. I don't believe this is required in any of the other codes generally being referred to. It is not a bad standard to have all the time though not code required, but it comes into play with the Seismic Supplement. Your company, or a customer, can require it for all welds just to be sure they are ALWAYS D1.8 compliant.

Hope I made sense and understood the original question.

Have a Great Day, Brent

By waccobird (****)

Date 01-01-2010 12:48 Edited 01-01-2010 12:50

Scott
Thanks for the links
The aisc one was too old I think, it was gone.
and Happy Birthday
Marshall

By 803056

Date 01-02-2010 21:48

250 C is about 480 F

Al

By MBSims

Date 01-02-2010 14:46

For many plain carbon steels, such as A36, the maximum interpass temperature is not critical. For fine grain steels where notch toughness properties are a consideration, it is common to limit the maximum interpass temperature in order to minimize grain growth in the HAZ. Grain growth would tend to decrease the notch toughness properties. Whether that decrease is acceptable or not is demonstrated by procedure qualification tests. Keep in mind, this is only a consideration where minimum notch toughness properties are specified by the applicable fabrication code or job specifications for the work being performed.

By Nanjing Date 01-04-2010 10:15

He is welding EH36 material. -40C properties. Too high an interpass and heat input will degrade the properties.

By Stephan (***)

Date 01-05-2010 20:53

Nanjing,

what would be your recommendation from your conclusion?

Stephan

By Nanjing Date 01-05-2010 23:01

Stephan, restrict interpass temperature and heat input.

By Stephan (***)

Date 01-06-2010 18:20

Nanjing,

an unclear question often leads to an unclear answer thus, I should have expected an answer like this. Thanks anyway!

Correct me, but I guess this is common sense.

To get back to the question of the Original Poster, asking for the reasons of the - as he assumes - 'high' interpass temperature.

As I am honestly not familiar with this grade of steel nor I have known the designation 'EH 36' before I read it here I did a quick research.

If it is a TMCP steel, and if we may assume that the application deals with a multi-layer weld, and if we then finally assume that the interpass temperature should be equal to the preheating temperature, then - even though a row of assumptions - my question would be. Is a preheating temperature of ~ 250°C regular rather for this grade?

And to be more precise with respect to - particularly - your recommendation(s). Is there any data available in AWS D 1.1 or should the preheating temperature be calculated rather by well-known procedures (Carbon equivalent,...). Or, would you recommend in this particular case to simply ask the steel supplier for detailed information?

Cheers,
Stephan

By MMyers

Date 01-06-2010 19:08

EH36 is a steel typically used for shipbuilding applications. It's a high strength structural steel with a YS of 51 ksi and min elongation of 21%. If someone is willing to dig through the SVR, the preheat/interpass temp questions will likely be answered, my initial attempts at finding the info came up with zip. From the 2010 ABS Steel Vessel Rules, Part 2, PDF Page 40, I left all of the notes out.

Chemical Composition (2)   (Ladle Analysis), % max. unless specified in range
C    0.18
Mn    0.90–1.60 (3)
Si    0.10–0.50 (4)
P    0.035
S    0.035
Al (acid Soluble) min (5, 6).   0.015
Nb (6, 7)    0.02–0.05
V (6, 7)    0.05–0.10
Ti    0.02
Cu (8)    0.35
Cr (8)    0.20
Ni (8)    0.40
Mo (8)    0.08
N    —

http://www.eagle.org/eagleExternalPortalWEB/ShowProperty/BEA%20Repository/Rules&Guides/LinkedGeneralGuideTitles/Current/Part2RulesforMaterialsandWelding

By Stephan (***)

Date 01-06-2010 21:03

Wow!

Mike that's one of an information!

Thanks a lot!

Stephan

By Nanjing Date 01-06-2010 22:16

Stephan, I do not quite understand how you made the assumption that min. preheat and max. interpass should be the same (make it pretty hard to weld). EH36 can be suppled in the normalised condition (usual I think) or by TMCP. As to minimum preheat/max. interpass temps that would be governed by the manufacturing route in this case. I maybe wrong but I do not believe AWS deals with this. Glad to hear if it does.

By Stephan (***)

Date 01-06-2010 23:53

Nanjing,

first of all, thanks for the reply.

If memory serves correctly I mean to have learned that someday. But as far as I remember it was no speech of particularly 'minimum preheat' and 'maximum interpass', just preheating temperature should equal interpass temperature or so. I mean it has also dealt with a Q&T steel grade but I'm not sure, so I must have a look into my notes. I'm certain I'll find it again. I felt remembered on this as I have read your previous response saying: '...restrict interpass temperature and heat input.', what was finally the reason for my assumption.

You made a good point. Even if supplied in the normalised condition, wouldn't you - as 'Nanjing' - judge a preheating temperature of 250°C as generally too high for this 'EH 36', independently of the required - or restricted - maximum interpass temperature during welding?

According to what BS EN says, preheating temperature as a linear relationship to the CE can be calculated as:

Tp = (CE x 750) - 150 [°C]

Let's assume the material would have a CE of 0.5, even then we would - theoretically - touch down at 225°C.

I mean 250°C is not a few and not only to maintain this appropriately to a specific distance to the joint (either 3 x t or 75 mm or similar) appears quite tricky to me. Handling this temperature during welding, hmmm... like you said, "...makes it pretty hard to weld...". I wouldn't envy the fellow who had to accomplish this.

Just my humble opinion.

Cheers,
Stephan

By Shane Feder (****)

Date 01-07-2010 00:53

Hello guys,
Stephan,
The minimum interpass temperature and minimum preheat are the same.
For example 75 degrees celcius is the minimum preheat and 250 degrees celcius is the maximum interpass temperature.
If the welding is interrupted between passes and the interpass temp falls below 75 degrees C it will need to be preheated again.
And if the temp is greater than 250 degrees C between passes it will need to be allowed to cool before starting the next pass.
The only reference I can find to maximum interpass in AWS D1.1 is in Tables 3.2 and M-1.

3. For ASTM A 709 Grade HPS70W and ASTM A 852 Grade 70, the maximum preheat and interpass temperatures shall not exceed 400°F [200°C] for thicknesses up to 1-1/2 in. [40 mm], inclusive, and
450°F [230°C] for greater thicknesses.

• For ASTM A 514, A 517, and A 709, Grades 100 and 100W, the maximum preheat and interpass temperature shall not exceed 400°F [200°C] for thicknesses up to 1-1/2 [38 mm] inclusive, and 450°F
[230°C] for greater thickness.

Hope that helps,
Regards,
Shane

By Stephan (***)

Date 01-07-2010 08:23 Edited 01-07-2010 11:36

Shane,

it definitely does - thanks! And as somebody has apparently found his in secret pleasure on rating some fellow members down to the ground, I'll give you a '3' for this valuable response!

By the way, I had a look at the notes I mentioned yesterday. I've found it in KOU's 'Welding Metallurgy' Ed.1, pp. 338.

He writes - dealing generally with the welding of Q&T steels, (quote):

"To meet the requirements of both limited heat inputs and proper preheating, multipass welding is often used in welding thick sections of high-strength quenched and tempered steels, such as HY-130. In so doing, the interpass temperature is maintained at the same level as the preheat temperature." (unquote)

This was the predication I felt remembered to as I have read Nanjings previous response.

Anyway, thanks again!

Stephan

EDIT: Hahahahaha! I have anticipated this! Rumpelstiltskin rules the rating system.

By Nanjing Date 01-07-2010 12:19

Stephan, I think your text book should have made it a bit clearer as Shane indicated by his post. Your quote makes reference to "interpass temperature". Is this minimum or maximum? Minimum is often required. How do you keep them the same? Surely as soon as you start welding the temperature increases?

By the way what have you been drinking when you wrote your post? I want to try it!!!!

By jwright650 (*****)

Date 01-07-2010 12:41

>By the way what have you been drinking when you wrote your post? I want to try it!!!!

Are these comments really neccessary? Just asking.

By Nanjing Date 01-07-2010 12:54

"EDIT: Hahahahaha! I have anticipated this! Rumpelstiltskin rules the rating system".

He's having a laugh and I am having a laugh too!

What's it got to do with you? Have a technical input if you can before you want to join in.

By jwright650 (*****)

Date 01-07-2010 14:06

>What's it got to do with you?

It has alot to do with me, and I certainly don't want the insults to continue to escalate at the pace they have been in the recent past. None of that is good for the forum and it does nothing constructive for the subject at hand.

By Stephan (***)

Date 01-07-2010 18:40

Hi John,

I would like to take the chance to spend one or two honest and respectful words on this.

This, as I have the bad feeling that it was eventually me, whose statement has unintentionally led to the unfortunate escalation.

I'll keep it short therefore.

This early morning as I stepped into the forum I could fortunately read a response coming from one of our very estimable forum fellow members, Mr Shane Feder.

I was happy as his response has shed some light on an issue which was a bit confusing me, what can be pursued by reading the thread.

What however I could instantaniously see as well was, that his response was marked with 1(!) diamond which was - at least in my understanding and with all due respect - a simple brashness and ridiculous. Together with the - in my eyes - also ridiculous low markings for Nanjing - which I had noticed certainly as well - I had to clearly express what I myself was thinking about even such a ridiculous behaviour. That was. I mentioned to rate Shane's response with 3 diamonds owing to the information it contents and to appreciate the time and work he spent by typing it into his computer to share it with all of us. That was the least I could do.

But... of course I have anticipated to be 'punished' short-term rather by having done so.

And as I have returned back to the forum a short while after. Yes! I must honestly confess. I must louldy and heartily laugh about this ridiculous behaviour as I have been marked even as well with 1 diamond.

You know, John. This marking system - I don't want to repeat myself - but this marking system has become even that what some of us have expected it would become someday. A tool which enables some sad people to suppress others by living out their ridiculous addictions.

My statement may - intentionally - polarise, but it was founded on a sudden thought. Namely, as I saw what I had anticipated, a little bearded and croockbacked dwarf flit through my mind and I thought by myself "Huui, Rumpelstiltskin has jumped off the forest to showing the world again that he is the true master of marking system but... what little spirit he yet actually is!"

I have received a very esteemed PM recently, coming from one of the great ones of the forum. He has mentioned 'professionalism'.

What a wonderful thought...

Sorry John, I may be banned for what I did, but I simply couldn't resist!

Stephan

By ross

Date 01-07-2010 16:45

Banned. Regretfully.

Ross
AWS Marketing

By tjinsp

Date 01-07-2010 20:26 Edited 08-26-2012 21:00

By ross

Date 01-07-2010 20:33

I think we ban about one person every year. I don't like to do it.

Ross

By Stephan (***)

Date 01-07-2010 18:02

Good Heavens,

what has happened in the meantime?

Just a few hours passed and I don't know if I should - or even may - reply on your response.

To keep it all together anyway. Yes, most likely you're right by saying the textbook should have made it a bit clearer. Like I said. Shane's post was most valuable - at least to me.

Then to reply your additional question (quote) "...Stephan, can you tell me where this formula comes from I have never seen it before? Normally BS and BSEN reference curves relating to CEV/Thickness/HI/Process/Minimum Preheat and of course this only relates to the avoidance of hydrogen cracking. (unquote) - not knowing anyway whether you could read it even.

The BS EN I have referred to was not BS EN 13916:1997 - Welding - Guidance on the measurement of preheating temperature, interpass temperature and preheat maintenance temperature. I guess this is what you have meant in your reply.

I have referred to BS EN 1011:2001 Welding - Recommendations for welding of metallic materials - Part 2 : Arc welding of ferritic steels (page 34).

It's using the following carbon equivalent equation:

CET = C + ((Mn+Mo)/10) + ((Cr+Cu)/20) + Ni/40

Hope this helps, although you appear as to be banned. And I must agree with Ross. Regretfully!

Stephan

By jwright650 (*****)

Date 01-07-2010 18:37

>not knowing anyway whether you could read it even.

Stephan,
He can read it...he just can't post any longer.

By Stephan (***)

Date 01-07-2010 18:46

Thanks for that John!

By Nanjing Date 01-07-2010 13:00

Stephan, can you tell me where this formula comes from I have never seen it before? Normally BS and BSEN reference curves relating to CEV/Thickness/HI/Process/Minimum Preheat and of course this only relates to the avoidance of hydrogen cracking.

By 3.2 Inspector (***)

Date 01-07-2010 13:45 Edited 01-07-2010 13:50

Stephan might referred to this:

Tp = 697 x Ceq + 160 x tanh (d/35) + 62 x HD0.35 + (53 x Ceq - 32) x Q - 328 (Celcious)

Or

Tp = TpCEQ + TpHD + TpQ (Celcious)

3.2

Thanks for the rating jrw159 :)

By js55

Date 01-07-2010 20:39

Not sure we still have the technical expertise to take up the slack should Nandesh have continuing CVN trouble.

OK. Sorry bout that. Couldn't resist. I'm done.

By tjinsp

Date 01-07-2010 21:45 Edited 08-26-2012 21:01

By ssbn727 (*****)

Date 01-07-2010 22:18

So tjinsp!

And what do you think YOU are doing in posting such a remark??? Exactly!!! Amazing!!! A HUMAN ECHO!!! ;)

There's no need to continue this thread any longer, and that much I agree with you, but to call someone what you just did and insinuate the jibberish you just posted only continues to perpetuate the unnecessary continuation of this, or any other thread like this one! I say END THIS NOW!!!

Respectfully,
Henry

By js55

Date 01-08-2010 13:34

Henchmen??? :)

By 3.2 Inspector (***)

Date 01-08-2010 14:01

I dont get it...
Keep in mind that I am blonde.

3.2

By js55

Date 01-08-2010 14:17

I thought Nanjing was a little too disparaging when it came to the advice offered by others.

By nantong (**)

Date 01-09-2010 02:01

Excuse me what does "disparaging" mean.

By nantong (**)

Date 01-09-2010 02:14

EH 36 minimum preheheat (minimum interpass) 10C and maximum interpass temperature 300C in the normalised condition.

If manufacturing route is TMCP limit maximum interpass temperature to 250C.

let the sunshine.

Nantong.

By Stephan (***)

Date 01-09-2010 09:00

Nantong,

now we know it really exactly.

Combined with the response coming from Nanjing saying:

(quote) "EH36 can be suppled in the normalised condition (usual I think) or by TMCP. As to minimum preheat/max. interpass temps that would be governed by the manufacturing route in this case." (unquote)

this makes sense.

This should then also finally answer the Original Posters' question and showing him: 'Everything's good!'.

And the rest of us may assume that he's - most obviously - welding a TMCP 'EH36' grade.

Thanks!

Stephan

By ross

Date 01-09-2010 16:06

Means disrespectful, showing a lack of honorable character.

Ross

By nantong (**)

Date 01-11-2010 14:09

能您讲中文

By ross

Date 01-11-2010 15:03

No, sorry.

Ross

By jwright650 (*****)

Date 01-11-2010 15:11

>Can you speak Chinese?

babelfish translated

By Stephan (***)

Date 01-11-2010 16:57

You're truly a great one, John!

I guess there's very few you're not able fix! :-)

Regards,
Stephan

P.S. Can't help myself but somehow I'm having such an apprehension...

By nantong (**)

Date 01-12-2010 13:01

The wonders of modern technology!

By Stephan (***)

Date 01-12-2010 18:03

Nantong,

good to know that we have both.

Those and John Wright! :-)