API 5L 46th Ed. Rejection of Line Pipe due to chemistry

Fred, The ladle check is the heat chemistry, this is done on the molten material.
I guess if someone wants to be didactic they can reject this.
But given that there are multiple product checks and they are within spec (not even having to use the additional tolerance) I think that they are overreacting.
If it were me I might demand a few more product checks.
Were the ones take from the first and last slabs of the heat? Or don't they say?


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P.E. Metallurgy

Not sure how to answer your question. This is LSAW pipe and they buy slab from Mexico and convert it at the mill into plate then roll the pipe.

I went to the mill and asked them directly if in API product supercedes ladle and they were very vague. They finally responded positively yet the

customer is still questioning.

The mill has certified the material to API 5L X52 But the customer keeps requesting justification as to their findings.

Me to customer :
Subject: FW: FW: FW: I have a rejection and have a simple question to put forth...
Good morning,
I am pleased to report that the mill HAS confirmed (see below) that product over rides ladle in API 5L analysis.
In speaking to the mill it seems that Table 5 clearly states and makes no reference to Ladle at the top, Heat and Product is the qualifying criteria:
Kindest regards,
Fred
Manager
Vass Pipe

Mill comment:
Fred,
QA:
API requirements for chemical composition is based on heat and product analyses not ladle.
Thank you,
Vickie

Customer response to above:

Fred,
If ladle and heat are not synonymous, and heat AND product are both qualifying criteria, where is the heat analysis on chemistry on this MTR?

Corporate Purchasing Manager
*** Fabrication, Inc.

This is a major fabricator building an oil platform going out internationally

I have attached the MTR for your perusal

Thanx for the quick response



Vass Pipe API Line Pipe Industry Leader

Given that Mn has a high vapor pressure, Mn is normally lower on product than on ladle. Unless there is a request that explicitly indicates Mn must be ladle tested, i see no reason why it shall be rejected. ladle Mn is a "fake" number.

Thanx for your responses!

I'm still needing to know is API 5L based uopn Ladle or Product/heat.

-=Fred=-

Vass Pipe API Line Pipe Industry Leader

1) "Based on Heat and Product Analyses" means that both heat and product analysis shall meet the requirements. If heat analysis is arbitrary the title should read "based on Product Analyses". I do not know any standard where product analysis overrides the limitation on heat analysis. There is usually a tolerance between heat analysis and product analysis because of inhomogenities within a heat, different test methods, different test labs,....
In API 5L there is no tolerance, so it is up to the steel manufacturer to choose a chemical composition with a Mn-content sufficently low to respect the maximum value as well on heat as on product analysis.
2) The terms "heat analysis", "ladle analysis", "cast analysis" are equivalent. The sample is taken in molten steel. In modern steel mills, the sample is taken in the mould (or the tundish) during casting , so just before solidication, and therefore the difference between heat and product analysis should be minimal.
3) As the deviation to the standard is small, I would ask a concession request to the customer. If the customer declines, I would send back the material to the mill.

Can't believe they are making an issue of this. Product analysis is the only analysis that matters.
Is 'ladle analysis' included in various standards just a hangover from the distant past? Seems to me it is just a part of 'making the sausage'.

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

IM, there are still many specs that don't require a product chemistry, so the heat/melt/ladle chem is all that you get unless you impose additional requirements. The mills almost all check it, but they don't bother reporting unless they need to.
We used to require both, and they both had to meet the spec (no additional tol on the product chem) as we were going to have to analyze our product after mfg and we wanted to have the tol to use.

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P.E. Metallurgy

Just a quick update... our customer submitted MTR for approval to their customer and it ended up being approved.

Thanx everyone for your help and input.

-=Fred=-

Vass Pipe API Line Pipe Industry Leader