ASTM A572 Gr 50 vs Q345B

Date 05-01-2013 14:21

Hi Euskera

I can certainly not offer a "Solomonic solution", but would suggest that this issue is seen in the light of a risk analysis. What risks are associated with the failure of the components? Unless my understanding of the terms "gates, trash racks, etc" is not what you had in mind, I would say that the risk is low. (Possibly even negligible.) Under such circumstances I would be very surprised if the lowest grade steel available would be unsuitable for the application. That is not to say that you do not want a quality job. Certainly you do, but normally the anticipated failure mechanisms of such "tertiary" steel will not be "over stress", but corrosion, mishandling or failure due to poor fabrication practices. These failures are pretty much independent of the material quality, unless they are providing high carbon steel or something else that is unweldable. This is highly unlikely.

Given that the use of "non specified" steel may fall outside of the contract requirements, I would suggest that the matter goes through the owner's proper change control process, (Normally a Technical Query or Deviation request process.) so that the responsible people within the owner's organisation can evaluate the proposal and give approval or otherwise.

Regards
Niekie

By ssbn727 (*****)

Date 05-01-2013 22:14

Hello Euskera!

First off, the welding is to be produced as per D1.1/D1.1M correct? Well then, you need to learn the welding terminology relating to this code...
You wrote; "The Owner´s Representative has said to them that, for welding, they have to respect the Specifications of the Contract and perform the works as per AWS D1.1/D1.1M (elaboration of WPS and perform of PQR, Welder Performance Qualification and Welding Operators Qualification)."

"And, for the material, this Representative said that under any circumstances he will accept any change of the material (he suspects the chinese material has lower qualities, but can not say it openly)."

Well, that's just fine & dandy for some but GMAFB!!! WTF??? "(elaboration of WPS (Welding Procedure Specification)? - If you change the base metal, you then have to write up a new WPS because it's more than likely that you'll also change the filler metal as well so you're basically turning Red delicious apples into Green Crab apples... :eek:

"Perform of PQR"? I'm not quite sure what you mean here??? Welder Performance Qualification and Welding Operators Qualification... The second part of that sentence is misleading because, unless you're welding the component with adaptive control, automated, mechanized, or robotic welding equipment then the term "Welding Operator Qualification" is moot in this circumstance... In other words: N/A = Not Applicable...

So, A WPS = Welding Procedure Specification: A document providing the required welding variables for a specific application to assure repeatability by properly trained welders and welding operators... Then there's a PQR which is really this instead: WPQR = Welding Procedure Qualification Record: A record of welding variables used to produce an acceptable test weldment and the results of the test conducted on the weldment to qualify a welding procedure specification... And finally, a Welding Operator: One who operates adaptive control, automatic, mechanized or robotic welding equipment...

So it's important to know what the terminology means when one works to AWS D1.1/D1.1M because terms used with other standards & codes are not always the same in meaning once one is working through AWS D1.1 and people in here can get a better understanding of just what you're asking... What does the contract say?
What does the EOR say about producing a quality product less than the minimum of what the contract's written standard specifies? Let the EOR(Engineer Of Record) and either the owners rep or the owner himself decide which direction to proceed! :yell:

The Owner Representative couldn't fight his way out of a paper bag by the way he/she is contradicting the WPS against what the Owner told him and what is specified in the contract... So I would go down or up the chain of command, CYA, by getting all of the necessary changes in writing with the appropriate predisposing & follow on paperwork...
If you're QC/QA guy in charge then just do your job by observing & reporting and while you're at it, review how to fill out NCR's & RFI's and get them done properly, hand them in and see what happens...

Who knows!!! They may just call a "meeting of the minds" with the entire cast of characters involved which is how these things usually get straightened out! :eek:

I hope this is, or was helpful. :wink:

Respectfully,
Henry

By Shane Feder (****)

Date 05-01-2013 07:56

Euskera,
Not going to get into a lengthy discussion on the pros and cons of Chinese Steels but will make this comment.
I am on a very large structural project in Malaysia (modules are being fabricated in Malaysia, Thailand, Vietnam and China for delivery to Australia.)
We have a Project Specification for Fabrication
We have a Project Specification for Welding
We have a Project Specification for Painting
and
We have a Project Specification for The Use of Chinese Steels.

All comes down to you get what you pay for.
Cheers,
Shane

By nantong (**)

Date 05-02-2013 21:17

I will give you some advice on Chinese steel as I have been here in China for more than ten years. China has some of the most up to date steel making facilities in the world but there are still steel mills that use antiquated facilities with poor quality control. When buying steel in China I would advise you refer to approved manufacturers for each grade of material by way of bodies such as Lloyds, DNV etc on their websites for approved material manufacturers or as we did in the old days of BS 5750 go and audit your suppliers. If they hold an accreditation from a Western third party then you are managing your risk at least. It is always the first thing I look at, who made it? What the national standard is is less important to me. Over the years I have had more problems with steel from Eastern Europe than steel made in China.

Hi Shane me old mate, can you send me a copy of your Specification for use of Chinese Steels. I am sure it would be an interesting read. I have a lot of Chinese specifications translated into English (but they are not official as the Chinese version always take prescedence). I am in Luoyang Henan province working on three ball mills for Amec America.

By Shane Feder (****)

Date 05-03-2013 07:04

Nantong,
Have sent through to your e-mail.
Have never read the spec as it does not affect us - we are using AS/NZS steels in Malaysia, other parts of the project are being fabricated in China.
If it is like the fabrication / welding specs it will be a joke - you have to wonder what planet some of these people are on who write some of the specifications.

Al,
Understand exactly what you are saying but there are some significant differences in the scenarios based on some significant issues.

We are building a US$100 million Coal Shiploader in Malaysia for an Australian Coal Mine.
As per the contract all steel is to be AS/NZS steel - either imported from Australia or manufactured in accordance with AS/NZS specifications in various mills around the world.
We are looking at approx 1500 tons of material and we currently have approx 950 different items.
Tenders for large structural fabrications are based on a fixed price per weight of steel - not on individual items.
If the contractor wins the bid (based on the Australian mills quoted price for steel) they then have to issue a request to the mill for all the specific items.
If for example the design calls for a specific wall thickness of structural pipe and the Australian mill states they do not make it in that wall thickness then a Deviation Request goes in to use an alternative material.
We currently have approved over 40 Deviation Requests from our contractor to use alternative materials based on a variety of factors (excessive lead time, excessive cost due to small quantity etc).
All the differences in costs come out in the wash at the end of the project - sometimes the deviation request results in a cheaper material, sometimes it is actually more expensive.

Regards,
Shane

By Superflux (****)

Date 05-02-2013 21:18

"All comes down to you get what you pay for."

Shane, you NAILED IT!
3 years ago I was on a new construction power house project. The job specs specifically stated "No Chinese materials without pre approval"!!! Hey, this is Wyoming, we are proud Americans and believe in buying domestically when ever possible.
Careful scrutiny revealed that in order to be pre approved, a representative would basically have to go to China and personally pull samples from the laddle and witness the analysis.
Big "Oh SH!T"! 9/10ths thru we discovered this boo-boo that some 6,000 feet of small bore (2" and under) instrument S/S pipe had been ordered and over 4000' already installed. Oooohhh... change order time. After many Board room bludgeonings and the contractor prostrate and pennant on their knees, the Owner agreed that a full documentation of all offensive Chinese pipe be made and samples from each and every Heat number be cut out and sent in for independent analysis. Lucky for me... I always manage to get the really cool gigs... A week later after rhesus monkeying my way from the very bowels of the basement to out in the middle of gawd awful nowhere with a porta-band, I managed to find all the samples of each and every offending heat number. Ever run a bandsaw with one hand stretched out 237 feet out yonder in the air??? And you think we just stroll around with a clip board in one hand and QC Johnson in the other... Sometimes I considered using 3 lanyards. A solid 2 point respectable tie off and a third around my neck just in case the other two failed, I would be lynched and spared the horror of that 5 second dive into eternity.
Well, 3 weeks later (Project and QC Managers slamming shots of Maalox like it was tequila on Spring Break) after submission of the report, my bagged and tagged samples' Chemical and Mechanical report came back to me. All passed with flying colors. The carbon was nearly undetectable, chrome was top end content, and the nickel % was maxed out (all 304 and 316 stuff). Plus the mechanical tests were the "best" their engineer had ever seen.
Talk about a polished turd...
Bottom line was that the procurement folks did their job on spec'ing out the PO properly.
You CAN get what you pay for, anywhere.

By nantong (**)

Date 05-02-2013 22:17

Superlux, I think the language divide is increasing!

I can hardly understand what you are trying to say!
Why do you wait and build in Chinese material without checking first. In China my experience is for instance for making buildings which include rebar two samples are cut and sent for testing under client witness, from every heat, similarly for all stainless steel items are checked by PMI by the purchaser.

By JTMcC

Date 05-03-2013 03:05

My guess is that the other contractors who bid the job, to the specs (and lost the work), would be interested in the result of this.

Think of the possibilities.

J

By Superflux (****)

Date 05-03-2013 04:09

JTMcC,
I never really thought about that. Good point. Maybe some day I'll be back there having a beer and get "The rest of the story".

Nantong
Most of this pipe was installed before I came on to the job.

By JTMcC

Date 05-05-2013 16:07 Edited 05-06-2013 00:41

There are contractors who like to lowball, get the work, then try to make it up on change orders and like mentioned cheating on specs.

That's irritating to people who bid the specs.
Sometimes it doesn't work. I know of a large job going right now that has 3000 high purity orbital welds that have to be cut out (12,000 cuts and 6000 welds). Didn't pay to try and cheat on the purge that time. But they will probably try it again someday.

There are about 4 or 5 contractors on site that would of done it right the first time.

On the same job, same subcontractor, last year on CS pipe tried another little scheme that would of made them a ton of money, except they ended up spending 4 extra months making weld repairs and lost a very large amount of money. They could of made a very reasonable profit by following specs from the start. But that greed deal gets into a lot of peoples heads so they cheat.
Some times the honest guys really do come out ahead on the job.

J

By fschweighardt (***)

Date 05-03-2013 11:28

As a guy who is sometimes on the Owner end, and also occasionally on the Fabricator end, I have felt the pain on both sides of this issue.

However, when we bid a job, we spend beaucoup time reading the @%$#% RFQ. I will say right up front, that we work on tiny tiny items. Last project of note was a piece of stainless pipe with a few ells and a valve, all welded through about a 20" flange with a 6NPS hole. The entire thing was maybe 300 lbs, and about 6 feet long. It was for a major energy company, and of course they had outsourced all the engineering and procurement. We ended up with 2 2" binders full of (not women) but project and purchasing specifications. We saw the specs at the same time as the RFQ came out and immediately added 50 hrs to the project just to READ the damn books. Turns out we had a conference call every morning and a big e-mail confirming the questions/answers and decisions every afternoon by all parties.

We did this for 4 days, and at the end of the week, the project manager said:
"Wow, you guys really read that stuff"

We said:
"We thought that was why you sent it"

We had to jump through so many odd little hoops due to:
authorized materials vendors, countries of origin, even crating requirements (3/4" plywood, painted a certain color, labeled a certain way)

Finally at last we were able to come up with our price and delivery

Moral of the story: Read the RFQ, do what it says, and charge accordingly