Welding Filler Metals 3

[nadfourchon]

I have a WPS with the filler metal specification 4130, manufacture Techalloy, F-No. A & A-No. 11. Testing of this procedure had Charpy Impact testing at -20C. Is it acceptable for me to use filler metal from another manufacture other than Techalloy as long as the specification is 4130, F-No. A & A-No. 11?

 

[metengr]

Yes.

 

[tomwalz]

Dear Metengr:

I usually consider your answers simple, clear, concise and extremely pertinent. This one is the finest yet.

Tom

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[REGRUMBLE]

It is by code but I have often seen customers specification that indicates all procedures must use the same manufacturer for production welds as was used for the procedure testing. Check your contract documents.

 

[metengr]

Why? There is no technical rationasle and most suppliers would be forced out of business. This is why you have filler metal specifications.

 

[EdStainless]

Why do users continue to use any trade names in specifications and purchasing documents?
We see it often, we will quote both of the options, the brand that they stated and a technical alternate.
This is what UNS numbers are for, to prevent these kinds of questions.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[nadfourchon]

I did find out that when welding using a DNV WPS in accordance with DNV-OS-C401, which I am, you only need to requalify a different brand if charpy testing was done below -20C or consumable classification is different. I test at -20C so I am ok to change brands.

 

[SJones]

If only all welding consumables were the same!!! Many oil and gas operators are very picky when it comes to consumable suppliers, with good reason: they have suffered failures after the procedure was qualified with consumable supply from one location followed by supply of production welding consumables from another, particularly those forming local joint ventures in 'less restricted' parts of the world!! And that's why DNV have it in their offshore structure fabrication specification only they don't go as far as to restrict the manufacturing location.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[metengr]

Understand. This is why you have customized welding consumable specifications, if applicable, and work closely with more than one supplier. Relying on one supplier can result in a similar trick bag where the welding consumables may not remain at a consistent quality level . There is no guarantee that one vendor is going to always meet welding consumable specifications.

 

[stanweld]

I find it somewhat difficult to believe that a filler metal designated as 4130 can meet A-11 analysis - 0.17% C max. and a 1.25 to 2.25% Mn range.

I must second Steve's comment. Not all manufacturers' filler metals trade designations for a given classification are created equal. I have experienced many such instances when trade name purchase changes provided unaceptable welds (X-ray quality) or welds with unacceptable mechanical properties. I have also seen these types of problems from the same manufacturer's trade designations manufactured at different locations.

 

[nadfourchon]

The problem that I am having is that the WPS that I am using and have used since 2005 is producing hard welds. With in the past six months it has been getting more frequent. Our welds must meet NACE MR-0175, 237HBW max. Lately we have have been getting hardness in the high 200's HBW low 300's HBW. We tried welding without our shielding gas bulk tank and used single bottles, which made no difference, then we verified that we were within our WPS parameters, heat input, and that has not made any difference. So that is way I am questioning filler metal quality.

 

[SJones]

Why are you trying to achieve hardness limits for H2S service when fabricating an offshore structure?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[nadfourchon]

We weld on Marine Drilling Riser, main tubes and auxiliary lines (Choke, Kill, Mud Boost and Hydraulic Lines).

 

[gtaw]

F number - A is a new one for me. Where does that come from?



Best regards - Al

 

[nadfourchon]

ASME Sec IX QW-442

 

[stanweld]

nadfourchon,
QW-442 is for A-Numbers - not F Nos; furthermore, the chemistry of 4130 low alloy steel does not meet the requirements for A No. 11, as I had previously stated.

 

[stanweld]

nadfourchon,
Also note that QW-404.4 states "A change from one F-Number in Table QW-432 to any other F-Number or to any other filler metal not listed in Table QW-432; the 4130 filler metal is not listed in Table QW-432.

Based on your own stated problems regarding hardness (strength/ductility) issues, it would appear axiomatic that you would qualify a procedure using a different manufacturer's 4130 filler metal.

 

[SJones]

Shouldn't you be using DNV-OS-F201/F101 for welding on drilling risers?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[metengr]

nadfourchon;
As I read more of this thread from others that have contributed good comments, it appears you have a very serious problem with how your filler metal was originally specified versus worrying about purchasing this same filler metal from another supplier.
There seems to be significant confusion regarding the chemical composition of the filler metal, and if it was custom made to match 4130. Weld procedures can be qualified with coat hanger wire and as long as you have some specification or nominal composition and another supplier can provide their product to this specification you do not need to requalify the procedure. This is purely administrative.
Your problem as I now see it seems to be what you have in terms of actual welding consumables. If need be have this filler metal analyzed after welding bead on plate. You may be surprised as to what was supplied.
Welding 4130 can be done with several recognized filler metal specifications from E 7018 to E8018 B2. The selection of the filler metal is based on desired strength/hardness level.

 

[REGRUMBLE]

Any good welder will tell you that there is huge differences from one brand to another even though they both meet the same UNS and filler specifications. If the welder is confident with the electrode the end result is a lot better than if he is fighting with slag inclusions all the time. I do not mean to indicate the welder should dictate the brand but we often get three or four brands and test them all to determine which one is both cost effective and user friendly as well as meeting code requirements.