American Welding Society Forum
I am Michael, I am a mechanical engineer,
at the moment, I need to do TIG weld 17-4H1025 (150 KSI Yield strength, 160KSI UT strength, 39HRC).
Weld sample is tube, OD 3.6" , wall thickness .2" ( OD 91mm, wall thickness 5mm)
I'm using Rod ER630, 1.6mm and Argon 99.99% , Flow rate 16l/m , Amps 150
We have welded 2 times and sent the samples to Third Party Laboratory Test in accordance with ASME Section IX (2010)
But all samples failured at bending test. All samples broken. Note: the result after testing: 148 KSI Tensile strength at weld metal, Bend test: broken.
I realy don't know how to solve this problem now.
Could someone please advise me something in order that I can pass the test. (e.g : amps , volts, Flow rate, .... or anything )
I am looking forwards to your help!
Thank you very much,
Just a thought,
Review the MTR for your material and make sure everything looks OK.
You may want to start there and see if the material is the correct 150ksi yield. If the material is the wrong yield you may never pass regardless of how many times you send it out to the lab.
BTW, are these Fillet welds? or Groove welds?
What condition are you purchasing the material in?, and what heat treatment is this getting after it is welded?
Every product data sheet that I looked at online says that this needs to be considered to obtain the best mechanical properties.
I'm not familiar with this type of stainless, but maybe someone else can help you narrow down your problem if you reply back with the heat treatment conditions.
Hi John Wright,
Thank you very much for your reply soon!
MTR is OK. But there is one thing notice. Usually 17-4 at H1025 heat treat condition has 145 ksi yield (ASTM A564). But our customer require 17-4H1025 with 150ksi yield, so we purchased it.
This is Single U groove. Weld metal is as welded, no PWHT.
I will try to send some picts for reference,...
you need to learn to weld a bit better
Welding on 17-4 H1025, in my understanding, is not recommended. You need to either acquire it as annealed or as over-aged, i.e., H1100 to 1150.
The ductility is very low to start with.
The as welded microstructure of 17-4 PH is untempered martensite.
You have pinholes... a sign of contamination.
be it shielding gas or foreign substance of any kind.
keep it clean and maybe up your gas flow
hope this helps.
thank for your time and consideration.
And I thought I was the only person who spotted poor welding!
Bump...hoping Al or MMyers (edit* or Jeff....LOL)will chime in here and help with this question regard this material and the heat treating problem causing these mechanicals to be off from the target.
I'm going to assume that the lab is using the correct bend radius in their coupon bender for this 150ksi material.
I'm also going to assume that the bend radius for this material would be much larger than what I use for 50 ksi and less materials.
Here I post some picts of sample test,
Hope I will recieve comments more.
Are they getting bent in a press brake?
Sorry I did not observed How the Lab did bending test.
I just sent the samples to the Lab then they performed bending test in accordance with ASME Section IX.
The Lab is the Third Party so I belive they did correctly.
Michael, I doubt you will ever succeed in successfully passing any bending tests using this joint configuration. It's a partial penetration weld! From the slightly unusual nature of the material, I would guess it's being used for it's corrosive merits, but then you go and introduce a massive crevice into the path of the medium. Are you back purging the tube whilst welding? Why not a conventional full pen weld?
The picture of the finished weld has a large surface breaking gas pore visible.
The macro has a crack initiating from the root by the look of it.
Check the lab are using the correct radius on the bending machine as per ASME IX QW 466.1
I agree.....hard to overcome all of those obstacles that you pointed out. Even the most forgiving of materials will fail given these circumstances.
>It's a partial penetration weld!
>The picture of the finished weld has a large surface breaking gas pore visible.
>The macro has a crack initiating from the root by the look of it.
>Check the lab are using the correct radius on the bending machine as per ASME IX QW 466.1
....and that bend radius appears to be very tight, Note the picture that I posted with the bend radius (1.5" dia plunger was used), I don't have ASME IX handy to reference, but just for an example, AWS D1.1 uses 2.5" for 90ksi and above materials
edit* you know the lab may have used the correct bend radius, but the material started folding over before it could conform to the plunger/die, mostlikey due to the fact that it is a partial pen and started cracking from the unfused portion of the joint. That unfused portion of the joint is a huge stress raiser.
OK, I think I know what happened...sure looks like they used an incorrect bend radius to me.
Here is a picture of a coupon with a bend radius for mild steel (less than 50ksi), the higher the strength, the larger the radius should be.
HAS to be incorrect bend radius, crossed with D1.6 even its 1" at least... Must be that CWI whos mag checking aluminum.
look at the x-ray.
NO penetration on the root.
hope this helps.
thank you for your time and consideration.
the first pic..
says macro sructure on it.
might be an etching.
anyway showing no root penetration.
hope this helps
thank you for your time and consideration
Erhmm... That's because this is a partial pen weld joint configuration.
Sometimes, no matter how much you try to drill an obvious fact into someone's head, the only result one gets is to become frustrated at the lack of understanding of something so obvious such as this partial penetration groove joint configuration... If one looks @ the HAZ in the picture one could easily notice that not enough current was used by the welder and since the welder had to work within the parameters listed, I believe the welder was being too conservative within the range allowed and should use clean torch parts because that torch is in bad shape for this type of work... Start again with very clean material and new torch parts and I don't know if you're using a gas diffuser but, it's not a bad idea to do so... Check your tungsten to make sure it has the correct angle for increased penetration and is sharpened/polished properly and clean!!! And then stay on the high end limit of your welding parameters and make sure your torch angle is correct... What do I mean? favor the thicker side of the joint just a slight bit more to insure enough penetration to that member of the joint... Run two root passes if possible in order to insure that there's adequate penetration into both members of the joint because according to that macro, there wasn't sufficient penetration into either member... Check your tungsten again and sharpen if necessary and make sure there's no contamination!!! Keep your parameters about the same to fill in the rest of the groove...
After all is said and done, make sure that the bend radius being used is the correct one because like JW, I don't think it is also... After you get all your ducks in a row, do some serious praying that you'll even make the 150 ksi yield requirement!
Finally, what is the rationale for using that particular joint design and why not just use a full pen config instead? I know there's a reason but, I cannot think of it currently.
I would like to say thank you very much for your help!
I will study your advice carefully.
And I will ask the Third party Lab about radius of die/plunger. May be it is too small.
With best regrads,
Its not ASME but according to D1.6 5MM wall thickness, at an 8% elongation is a 1" bend radius, MUCH MORE than whats in your photos
Hope that helps.
Also why is PJP getting a bend test? isnt it just a MACRO and VT??
46.00 , is right X- Ray first if they past the test then precede with the bend test might save some money. Has this part being through some chemical process before welding and are you brushing with a stainless steel brush between ever pass.
Now I am studying ASME Section IX again, may be the radius of die/plunger of jig bend test is about 32 7/8 x T ( ~ 32.875 x T, with T is wall thickness ) Because My English is not very good so I have difficulties in studying ASME Section IX.
I know that, If someone has ASME Section IX in hand and he is good in English, He can read and advise me.
If someone has ASME Section IX, please see QW-466.1, you can understand which is the radius of die/plunger of jig bend test
(my weld sample has 10% elongation).
But I know I should study ASME IX by myself ....
Long time to see you!
I hope to meet you again.
Today, I did searching on Google and found out an article which clarify Bending Test Jig Dimension.
The article does interpretation/explaination very clearly. But there is a value which makes me confuse.
Could you please advise me that the dimension 0.113” should be 0.130” (3.3mm) as per formula. (page 3 of 6)
My opinion is the article does interpretation/explaination correctly with the exception of the dimension 0.113” should be 0.130” (3.3mm)
Please advise me!
If I am correct/right. I will ask the Third Party Lab to use correct bend radius & correct thickness of sample test.
I hope you are willing to help!
Thank you very much!
The percent elongation you're using for the 17-4H1025 PHSS should not be 8%... It's actually 10% so with this correction your result should be changed if you take into account the change in percent elongation... Please make a note of this according to this link below:http://www.specialtysteelsupply.com/brochure/17-4-technical-data.pdf
Please refer to the chart listed on page 3 of 4 on the left side of the page, look for the second chart on the left side towards the bottom of the page...
Now 17-4H1025 isn't actually included in that chart, you do agree that H1025 would be in between H900 and H1075 correct? This is why I believe the specific grade you are using of 17-4 H1025 PHSS has an elongation rate of 10% instead of 8% which is what condition A has listed instead.
And I mention this because regardless of the possible incorrect calculation (I didn't even both to confirm if it was indeed a miscalculation), one of the variable values listed in this formula are not accurate in your application and is the reason I bring this to your attention... Good luck in finding the correct results you seek.
Thank you very much for your advice!
Yes, elongation of 17-4H1025 should be about 10% .
You are right
And I should use this value.
I will inform you when I have something new.
With Best Regards,
Several people have offered some good advice on the problem described. As happens too often to note, information is fed in bits and pieces, so it is difficult to provide good information or suggestions to the individual asking the question.
-The joint detail replicates the joint proposed for production (I'm taking a guess at this one).
-The PJP detail can be tested, but the samples should be machined to remove any material that is not fused so that the samples to be tested are "CJP." This requirement applies to both the samples to be subjected to a guided bend test as well as tensile tested.
-Since this WPS appears to be qualified ASME Section IX, it may be prudent to test a CJP groove hat is either welded from one side with backing on the root side or welded from both sides with a back gouge operation. AME does not differentiate between WPSs qualified with or without backing or welded from both sides. Joint design is not an essential variable per Section IX.
-Verify the appropriate bend diameter is used based on the final state of heat treatment used for production, i.e., if the final part is used in the "as welded" condition, then the WPS should not include any PWHT. If the component is subjected to PWHT before being placed into service, the welded coupon should be subjected to the same PWHT before being subjected to the mechanical tests.
It appears that the customer expects the components to be subjected to PWHT. The same PWHT should be used for the test coupon. The mechanical properties should be determined in the final state of heat treatment. Has anyone asked the customer if they have done any preliminary studies to determine if target values can be obtained? Did the customer specify which filler metal is to be used? Has it been verified the filler metal will produce the required properties after PWHT?
Best regards - Al
asme test probably of both welding and machining skills.
it took me 4 times to get right on a 6" bend ....but 6" is all I have in the shop.
on 309 ss..but cheap
real tough for both
but be clean and purge heavy is the key to the weld
btw... never did a partial pen weld
few things to be noted
1. control the heat input during welding
2. the samples pictures shows that a wrong bending diameter has been used for testing.
3. ensure the soundness of the weld joint by any NDT method which suite best.
Easy now Henry.
The poor guy just made his first post, having just signed up to the forum that day :(
heehhe, thanks dear, letting him to know, it was my first post.
I realy don't understand fully what you mean.
But I am trying to read more ducuments, specification to solve my problem
Please advise me more
Thank you very much,
Because My English is not very good so It is difficult to understand fully what you mean.
Sorry if I speak something wrong.
I will provide more further information about my situation now.
I hope you are willing to help.
Thank you very much,
With Best Regards,
Inside joke that's all Mike... American English is a whole lot different than what you're probably used to so don't read too much into it okay?
The same goes to Sandeepkumar... Btw, "WELDCOME TO THE WORLD'S GREATEST WELDING FORUM of THE AWS!!!"
:) Hello Henry, please check your inbox and reply
I have just welded another sample
Tomorrow I will do bend test.
Today I have performed Bend Test. The result is a little bit better now. The face bend is OK, there is no crack or broken .But the Root bend is broken completely. Root bend still has problem.
Yesterday I made The Bend Jig by myself.
Because the elongation of material 17-4H1025 is 19%, elongation of TIG Rod is 12%. So I dicided I should follow elongation 19% of material. So I used Radius of Plunge is R.394" (R10mm). Thickness of sample is .216" (5.5mm) (Note b as per QW-466.1, ASME IX.)
Now I repeat my trouble again, hope you will listen to:
I am welding 17-4 H1025, 150 KSI Yield Strength, 38HRC. Elongation is 19%
The Tig Rod ER630 has 12% elongation.
Last time we send samples to Third Party Lab. Both Face & Root Bend were boken.
Now I think that, last time Third Party Lab luckily used proper/correct Radius of Plunge. They follow calculation R=2t (they told me). But regarding to Elongation19%, It should follow Note b as per QW-466.1, ASME IX.
Note: Our customer do NOT require PWHT. That is my problem.
Can you please review and advise me further.
Thank you very much,
Sory for sending lots of Picture & files
But I don't know how to explain details to you.
Don't apologize, lots of pictures is good...that helps alot.
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