IRON PIPE Chemical Composition (no Carbon?) - Help determining type of Iron please 3

[AntonioCP]

Hello,

I have an SGS laboratory analysis report(image attached) of some Iron Pipes (see photo), for which I am trying to determine the type of iron. The SGS laboratory analysis does not indicate the Carbon percent... Is this possible, or must this be an error by SGS?

Could someone help determine what type of Iron (Cast, Iron, Ductile Iron, or other) does the chemical composition shown in the SGS report attached represent:

Thanks in advance for your kind help with this.
Antonio

 

Contracts for US pressure equipment projects I have worked on have had 'may not buy from C***a' clauses.
While these may be politically motivated, it turns out they are great for quality!

This forced me to source my duplex stainless steel welding wire from Sandvik. Experience has taught me that the best way to save money in fabrication is to give the shop quality tools and premium filler metals, so it suited me fine. Welders not 'blaming the wire' is the happy place for a welding engineer!

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

Good luck Steel Gal.
A tip: look out for decarburization in failed tubes, especially the exotic ferritics now being used in gas plants. Many other sins were committed during the manic combined cycle plant construction boom.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[Steel Gal]

I agree. My late husband was a extremely competent fitter/welder and would talk about flux core wire quality a lot. We never used garbage wire in our shop; if a welding supply house failed to give me documentation when I requested it, I didn't do business with it again.

Years ago I had my own personal run in with ESAB flux core wire that I won't get into here. If only they were actually making what they said they were selling to you. I hate liars.

 

You would be surprised at how many welding products from premium brands are made by others. And I'm not even talking about the relabeled, second-tier Far East junk.

A lot like gasoline - the stuff you just bought was more than likely refined at the geographically nearest refinery, not one indicated by the sign over the gas station.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[Steel Gal]

On this story I was not on the purchasing end, but a "whistleblower" concerning their product. Near my residence is one of their manufacturing facilities for making flux core welding wire. The employees went out on strike and the company hired scab labor as replacements. I was hired as part of that group, we needed the money.

So the company now has an unskilled labor force (including me) making flux core wire and shipping it to US Navy contracts, etc. I felt that the product could not possibly be any good - you don't learn to make welding wire in five minutes.

I won't say what I did, but I later learned that post strike the plant management and some of the staff were fired as a result.

 

[arunmrao]

SGal,
Very interesting experience you have. MST handbook was the bible for us young metallurgists in 1970's. I come from the other side of the world, where Mittal started his steel journey. They were steel scrap traders in Calcutta.

I work in a steel foundry and getting quality steel scrap is becoming a challenge especially with Boron and Vanadium contents.

Good Luck in your new assignment.

 

[blacksmith37]

Good grief , all these responses for some ERW line pipe . Photo shows steel ,likely X60 but anything from X-42 to maybe X-70 is possible . No cast iron. Likely a pinch of Nb ( Cb for old people).

 

Don't assume, because you know what can happen when you assume...

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[blacksmith37]

I do not assume ,I know that is ERW ( from what I can see). Ti an V are unusual so I assume it is Nb. I also assume it is not much over 40 years old. There are a dozen ways to verify it but i am old and type slow. Uniformity of wall thickness,- ERW is more uniform wall. ERW will have weld trim , not all but enough for ID. Metallography of some rings will show weld and (I assume the API required recrystallize), Real chemistry , For ID you only need the micro alloys ( Nb, v, Ti , and I assume no alloys have been added). Etc.

 

[dik]

Are these just trace elements? Something just difficult to get rid of and part of re-cycled metal?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[weldstan]

They are not residuals when purposely added and are considered micro-alloying elements. Wen I worked in a steel mill, we would add V (> .03%) and Nb (> 0.015%) to the steels to provide greater strength with less C. The skelp for our ERW pipe was exclusively C-Mn-Si killed and semikilled steels until I left in 1972. I know that by 1978, microalloying elements were added to both their ERW and sub-arc welded X60 and X65 pipe.

 

[blacksmith37]

I was not clear; by "alloys" ,I meant the traditional Cr,Ni,Mo for alloy steels. Yes, @weldstan, that is what I meant by " I assume not older than 40 years" because then they could have been traditional steels , and not TMCP - containing Nb, etc. Amoco had dozens of pipe ruptures of slit skelp semikilled ERW pipe. The manganese silicate/sulfide stringers just do not weld well. Sometime in that era , I added "no slit skelp permitted" to the Amoco pipe specs.

 

[weldstan]

Agree that semikilled ERW pipe produced far too many inclusions reaching the surface and could readily lead to failure in service. When I worked for a major EPC firm, I too wrote specs prohibiting the purchase of semikilled pipe for any of our petrochem, power, metallurgical and nuclear fuels reprocessing projects.

 

Eventually there will be a part per million of everything in everything.

I thought the problem with ERW was the low-frequency welding aspect, which (when combined with superficial NDE) left 'hook' defects at the joint. Either way, that stuff should have been killed (not semi-killed) in its cradle, considering the massive environmental damage caused by pipeline ruptures.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[blacksmith37]

The major problem with the old ERW was stringers in the weld (hook flaws). With cleaner TMCP the weld zone could have poor mechanical properties. API 5 added a requirement for recrystallizing the weld zone ( an induction coil after welding; metallographic verification is required). Manufacturers still wanted the option for cheap pipe so ( when I retired) Grade B only required reheating , not recrystallization. ERW can be very good pipe; Amoco was using a lot of 80 ksi ( and lower) casing.

 

You're correct, ERW can be high quality, but as the saying goes, "there's many a slip twixt the cup and the lip". LF-ERW failures do not have a single causal factor.

High frequency welding has made LF-ERW obsolete. I have seen cross sections of normalized welds that exhibit zero evidence of the weld; the only clue might be a very small notch or ridge on the inner or outer surface.

If I am writing a tech spec for welded pipe I would place strong emphasis on thorough NDE of every inch of long seam.


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."