AWS D1.1 Equivalent steels 4

[Nutznbolts]

Hello,
I built 600 tons of structural weldments in Asia using AWS D1.1.
All the parts were fabricated and tested, shipped to site and installed on time. Everything fitted perfectly. The facility is ready for use.

Now the customer's welding guy is claiming that it does not comply because we did not use ASTM steels as specified in AWS D1.1 and therefore we can't use the AWS D1.1 prequalified WPS. I don't believe he has a valid argument.

The steel we used (Pipe, plate and RHS) came from Europe, Asia and Australia. There is no issue with the steel quality.
All the steel we used is equivalent in chemical composition and strength. All the steel has been accepted by the design engineer.
All the steel complies with the AWS D1.1 "Group" definitions.

My arguments are:
• AWS D1.1 is for low carbon steel (Min yield strength 690MPa and below) so, inherently, there is low risk of failure by incompatibility.
• AWS D1.1 does not exclude equivalent steels.
• All the steel has been accepted by the design engineer.
• Use of equivalent steel is not an essential variable

Anyone else been confronted with this issue? How did you resolve it?

Thanks for reading and responding.

 

[Kiwi2671]

Nutznbolts,
You have got yourself in a rather large spot of bother as your customers welding guy is perfectly correct - your welding procedures do not comply with AWS D1.1.
I am currently in Malaysia on a large structural project destined for Australia and have recently completed 3 years in Thailand working with AWS D1.1.

Section 3. Prequalification of WPSs
3.1 Scope
"In order for a WPS to be prequalified, conformance with all of the applicable requirements of Clause 3 shall be required. WPSs that do not conform to the requirements of Clause 3 may be qualified by tests in conformance with Clause 4."

3.3 Base Metal / Filler Metal Combinations
"Only base metals and filler metals listed in Table 3.1 may be used in prequalified WPSs."

Are the materials you used listed in Table 3.1 ?
If they are you can use prequalified WPSs.
If they are not you cannot use prequalified WPSs and must qualify all material combinations with a PQR and relevant testing.
If not they are classed as unlisted steels and what you may weld with these PQRs is listed in Table 4.8.

The only person who can overrule this is the Engineer ( not the design engineer but the owners designated representative).

How did you manage to get yourself in this situation ? - fabricating 600 tons of steel without someoneone with a basic knowledge of AWS D1.1 being involved.

Good luck,
Regards,
Kiwi

 

[gtaw]

I agree with KIWI. Only the Engineer, acting in behalf of the Owner, has the authority to permit deviations to the code.

I would have to wonder why an Engineer would be willing to accept the fabricator's liability and put his practice, license, and reputation at risk simply to let the fabricator off the hook. It is one thing to make a proposal to allow a material substitution before fabrication, but after the fact is a different story altogether.

There are times when "nearly the same" isn't good enough.

We just settled a case where the fabricator made an unauthorized material substitution on a project. Fortunately the failure occurred during erection and no one was injured. The arguments put forth by the fabricator sounded nearly word for word like this post. We settled the suit for a tad under two million dollars. It was an expensive lesson for all involved.


Best regards - Al

 

[fegenbush]

If you had a PQR that used the same parameters as the prequalified WPS (with the exception of the material), you may have a leg on which to stand. Since testing is cheap (in comparison to lawsuits), I would get the material combinations you used and start welding test plates and getting them tested.

 

[KnaT]

I agree with the above comments. The best and easiest way out of it is that you weld coupons using the materials and pre-qualified WPS that you have used. Get them tested as per AWS D 1.1 and present the results to your Client.
I believe he will then ask you to use the information to develop your own welding procedures which is just paper work.

 

[21121956]

Hello everybody:

Hi Nutznbolts, I really beg your pardon, but I would like to know what was (or will be) the end of the story. What was the technically accepted solution to that situation? I wonder, what happens if the tests are not be accepted by the client? it would be necessary to undo the weldings or what way have to be taken?

If for any reason you are not able to answer to my questions, I would appreciate the comments of the other posters in order to get to know what is the correct way to follow in some instance like this.

Thanks to all.

El que no puede andar, se sienta.

 

[Rikwan]

Hi Kiwi2671 hou have to read the code in its full context.

I agree with the following section out of the code:

3.3 Base Metal / Filler Metal Combinations
"Only base metals and filler metals listed in Table 3.1 may be used in prequalified WPSs."

However, the word "shall", which is define as a mandatory requirement in this code, is not use in this sentence but the word "may" is use.

The definition of the word "may" in this code is as follows:

1.3.6.3 May. The word "may" in a provision allows the use of optional procedures or practices that can be used as an alternative or supplement to code requirements. Those optional procedures that require the Engineer's approval shall either be specified in the contract documents or require the Engineer's approval.

Therefore, the use of equivalent materials (not listed in Table 3.1) are allowed in prequalfied WPS because the word "shall" was not used to make it a mandatory requirement by the code.

 

[DekDee]

Rikwan,
They are not allowed to be used - unless approved by the engineer (and I am not 100% sure of that based on 3.4 below)and the OP has already stated that the Owners Representative did not allow it.
Table 3.8 states "A change in the base metal group number (See Table 3.1)" is an essential variable.
If it is an unlisted steel how can it possibly have a group number ?

The welding parameters set forth in Table 3.8 shall be
specified on the written WPS, and for variables with limits,
within the range shown. Changes to the essential variables
beyond those permitted by Table 3.8 shall require a
new or revised prequalified WPS, or shall require that the
WPS be qualified by test in accordance with Clause 4.

or

3.4 Engineer's Approval for Auxiliary
AttachmentsUnlisted materials for auxiliary attachments which fall
within the chemical composition range of a steel listed in
Table 3.1 may be used in a prequalified WPS when approved
by the Engineer.

Regards,
Kiwi

 

[pandithan]

Before proceeding, this change in material should have been approved by owner engineer

 

[Rikwan]

DekDee,
I will repeat myself again:
AWS D1.1 says the following in Clause 3:

3.3 Base Metal / Filler Metal Combinations
"Only base metals and filler metals listed in Table 3.1 may be used in prequalified WPSs."

The definition of the word "may" in this code is as follows:

1.3.6.3 May. The word "may" in a provision allows the use of optional procedures or practices that can be used as an alternative or supplement to code requirements. Those optional procedures that require the Engineer's approval shall either be specified in the contract documents or require the Engineer's approval. The Contractor may use any option without the Engineer's approval when the code does not specify that the Engineer's approval shall be required.

Therefore, there is no Engineering approval required in paragraph 3.3 of AWS D1.1 but a typical example where Engineer approval is required in AWS D1.1 is shown in paragraph 3.4 for the use of unlisted steel for auxilliary attachments.

If your material (Type/Grade) change on your Pre-qualified WPS you only revise your pre-qualified WPS to reflect your new material to be used. (One must be realistic that you will never fabricate a steel structure from a non-weldable material. The most frequently used material for steel structure world-wide is EN10025-2 Grade S355JR which is definitely not listed in Table 3.1, but is a 100% weldable steel for the use of the fabrication of steel structures). If there is still a problem with the use of unlisted steel have the material dual certified (EN/ASTM) or use dual certified material from the start, which bring us back to paragraph 1.3.6.3 "the use of optional procedures or practices that can be used as an alternative or supplement to code requirements".

It is not a code requirement that your group no. of the steel has to be on your WPS or PQR see Annex N (sample documents)of the Code. Why do you want to give your unlisted steel a group number? Group no. is only applicable for the materials listed in Table 3.1.

Table 3.7 is important for Pre-qualifed WPS as all the requirments of Table 3.7 shall be met for prequalified WPS where base metal is not one of the requirements in Table 3.7

Regards,

 

[DekDee]

Rikwan,
You make an interesting point about the use of "may" but I still disagree with you.

If engineers approval is required for unlisted materials to have pre-qualified status for auxillary attachments how can you possibly weld primary members with a pre-qualified WPS without the engineers approval ?

Table 3.8 states "A change in the base metal group number (See Table 3.1)" is an essential variable.
If it is an unlisted steel how can it possibly have a group number ?

I have been involved with AWS D1.1 in Asia for the last 5 years and the fact AS/NZS (Australia / New Zealand) steels are not recognised by AWS D1.1 has cost us a lot of time and money to qualify welding procedures.
A colleague of mine was heavily involved with certain AS/NZS steels being recognised by the AWS B2.1 committee but was told it could be at least 5 years before these steels were recognised by the AWS D1.1 committee.

So you are saying your S355JR may be used without qualification testing ? IMHO - definitely not.

Will wait for GTAW who is a former committee member of AWS D1.1 to add his thoughts,
Cheers,
DD

 

[gtaw]

I am happy to see we have a scholar responding to this question. An expert in the interpretation of English as used by the Americans that wrote the D1.1 Structural Welding Code/Steel. I just hope we are using the same edition.

While I am no scholar nor do I proclaim to be an expert in the use of D1.1, I do believe there is some twisting of the Ass' tail to derive a few of the interpretations of D1.1 that I am reading.

AWS D1.1 gives the Owner, through their Engineer, considerable latitude when it comes to code provisions. The Engineer can add to, supplement, or exclude certain provisions. When said additions, supplements, or exclusions are invoked by the Engineer, they must be included in the project specifications.

We do not privy to the contract documents that are involved, so we do not know what the fine print has to say about this project. We cannot be sure anything written in this thread has any bearing with regards to the project since we don't know if the Engineer did a good job or a poor job defining the terms and conditions that apply.

Use of the English language can be very muddied when it has been mutated over many years as it has. If the language was as clear and precise as we would like it to be there would be no need for lawyers. Clearly that isn't the case because the number of lawyers outnumbers the number of doctors in America.

I do believe the 2010 edition of AWS D1.1 structural welding code is clear that only those materials listed in Table 3.1 can be used for a prequalified WPS. Rather than simply quotig a portion of a sentence, it may be useful to cite the entire sentence. In this case the clause that applies is 3.3 Base Metal/Filler Metal Combinations - "Only base metal and filler metals listed in Table 3.1 may be used in prequalified WPS. (For qualification of listed base metals and filler metals, and for base metals and filler metals not listed in Table 3.1, see 4.2.1.)"

An exception to the requirements of clause 3.3 is allowed in clause 3.4 Engineer's Approval for Auxiliary Attachments when approved by the Owner's representative, i.e., the Engineer.

Further reading directs the user to Table 3.8 that list the welding variables that must be included in the prequalified WPS. Item 3) lists the base metal group number derived from Table 3.1 as one of the many variables that must be included by the prequalified WPS.

To take a step or two backwards to reread clause 3.1 may be of some use, "In order for a WPS to be prequalified, conformance with all of the applicable requirements of clause 3 shall be required."

Reading one or two clauses or one or two sentences from a single clause, without reading the entire clause and all the referenced clauses, tables, and figures can be misleading. It has been my experienced that a minority of contractors have developed a strange ability to read only those portions of the code that support their skewed view of what the code requires. I have coined the phrase, "Selective reading ability." It seems to describe the ability of those few contractors to twist the intent of the code to suit their purposes.

If there is a question regarding the use and application of AWS D1.1, it is the Owner's Engineer that has the authority to provide the final decision and judgment. If the contractor disagrees with the Engineer regarding the meaning or intent of a code provision the contractor can submit a request for an official interpretation from the AWS D1 committee. Only they, the D1 committee, are authorized to issue an official interpretation on the intent and use of the code.

A review of official interpretations of AWS D1.1 does not produce any questions regarding the use of materials not listed in Table 3.1 for prequalified WPSs. I would assume that would infer the question has not been an issue in the past. It could be that most contractors do not have a problem understanding the intent of clause 3 or the difference between a listed base metal and one that is not. However, in the current market and considering the fact that there is a good portion of our work going overseas, there is no doubt somewhat of a language barrier that comes into play. Again, my position is that when a question arises, it is the Engineer, i.e., the Owner’s representative, that has the authority to make a decision whether to accept the unlisted base metal or to require the WPS be qualified in accordance with clause 4 of AWS D1.1.

It can prove to be very costly for the contractor to forge blindly ahead and assume a material not listed in Table 3.1 can be considered a prequalified base metal. This would be especially true if American English is not the native language of the contractor involved. It is better to ask the question first than to discover at a later date a blunder has been made. Expensive lessons are valuable if the company survives the financial repercussions.

When in doubt, as the Engineer for clarification.


Best regards - Al

 

[DekDee]

Al,
A bit of an old interpretation and I think Table 4.1 in the 1990 edition was what is now Table 3.1 but it is pretty clear that if a material is not listed in AWS D1.1 it requires procedure qualification testing.
Cheers,
DD

Subject: Base Metal Qualifications
Code Edition: Dl.1-90
Code Provision: Table 4.1 and Subsection 5.5.1.3
AWS Log: ID 1-90-027-03
Inquiry: (1) A Group V to Group V metal of Table 4.1 weld qualifications is made. Is the procedure and/or
the welder qualified to weld a Group V metal to any other Group V metal listed in Table 4.1?
(2) A Group V steel to a nonlisted metal weld qualification is made. Is the procedure and/or welder
qualified to weld the nonlisted metal to any other Group metal listed in Table 4.1?

Response:
(1) No. Subsection 5.5.1.3 covers welding Group V to Group V base metals. However, the procedure
applies only to welds made [using] the specific ASTM material specification and minimum
specified yield strength as the base metal [for running] the procedure, without regard for
Group number. See the example cited in 5.5.1.3. However, the welder is qualified to weld all
steels in Table 4.1 by virtue of the fact that the material grouping of the steel is not a welder
variable.
(2) No. Steels that are not listed in Table 4.1 require procedure qualification and the procedure only
qualifies on the combination of materials tested (see 1.2.2). The welder in this situation again is
qualified to weld on any Table 4.1 material by virtue of the answer given to Inquiry (1) above.

 

[gtaw]

I saw that interpretation, but it didn't seem to be entirely relevant to this discussion.

The interpretation related to a specific grouping of steels listed by D1.1, whereas this post is regarding an unlisted base metal.

The question of applying an unlisted base metal to a prequalified welding procedure has been asked in other forums where the consensus was that the unlisted material could be used with the Engineer's blessing. However, any forum is informal, only the D1 committee can provide an official interpretation.

It is doubtful anyone involved in this particular project can wait 18 to 24 months for an official response from the D1 committee. I currently have two questions before the committee. One has been in committee for several months (about 12 or so). I was told that it would be several months before I can expect a response.

With the length of time involved, I would suggest the contractor involved simply qualify the WPS in question and move forward. While it may be an inconvenience to qualify the WPS for grooves and fillet welds, it would be the cleanest way to resolve the issue. Next time the contractor would do the correct thing and ask the Engineer if it was permitted to substitute one steel for another.

I would be very hesitant to permit the use of the unlisted steel if I was the Engineer, especially if the structure was being fabricated for an American project that was to be erected in the United States. In addition to the structural steel being required to meet AWS D1.1 requirements, it would also have to comply with AISC and American building codes. That could easily involve an American Building Official that would have to be comfortable with the Engineer’s decision to permit the use of unlisted steels. Is it worth the time and effort and the red tape? I don’t believe it is.

As a side note, I just finished a legal case where the contractor made an unauthorized material substitution. Unfortunately the substitution was responsible for a structural failure. I am happy to say we prevailed and my client was awarded restitution that included damages to cover lost profits, interest, etc. The contractor’s savings of a small sum resulted in a rather large financial loss for the contractor. A simple phone call to the Engineer before making the substitution could have saved the contractor and his insurance carrier literally millions of dollars.


Best regards - Al