Iron Powder

Date 11-07-2001 02:20

Not sure about the E7018 question.

You may be able to use E316 or E347 for high temps, depending on what base metal is being welded. What is the base materials and service temp?

Marty

By Mauricio Ibarra (*)

Date 11-07-2001 11:52

The base metal is AISI 310 and service temp. is 900 °C.

regargs

Mie

By RonG

Date 11-07-2001 13:47

If I were to hazard a guess I would guess the extra filler you gain from the Iron in the flux is unwanted (to much reinforcement maybe?).

The 7015 has Sodium and 7016 has Potassium in stead of Iron.

By R. Johnson (**)

Date 11-07-2001 16:11

I am not sure what you are asking about E7018 but I will try to give you some information. E7018 is a low-hydrogen potassium based covering that contains iron powder in the covering. E7016 is identical to E7018 without the iron powder in the covering. E7015 is a low hydrogen potassium based covering without iron powder in the covering.
E7015 can only be used with DCEP and both E7016 and E7018 have the ability to operate in AC as well as DCEP.
Why would some specifications prohibit E7018, not sure. It could be because some of the arc energy is used to melt the iron powder and therefore is not as deep a penetrating electrode as the other two. But usually most people just turn the amperage up to offset this. IMHO there should be no prohibition of E7018 just becasue it contains iron powder.

By RonG

Date 11-07-2001 16:49

Mr. Johnson according to my ESAB Data book there are 2 LoHi electrodes with 0% Iron powder 7015 and 7016. That was why I guessed the way I did, but I agree with you about not seeing a reason to differentiate.

By - Date 11-07-2001 19:51

I also can not come to a logical conclusion as to why the iron powder in E7018 would be a problem. Can you maybe tell us which specifications prohibit its use, and under which circumstances? Maybe then we can hazard a guess.

Regarding the E310, I recon that you should be able to use one of the Inconel rods. The only question being why you would want to use anything else on 310S/Steel.

Regards
Niekie

By Mauricio Ibarra (*)

Date 11-07-2001 20:41

Niekie2, I am going to find out with my clients about the type of technical specif. that prohibit using E7018 electrode.

On the other hand, I have to buy an electrode match E 310 because they are no in stock.

regards,

By G.S.Crisi (****)

Date 11-08-2001 18:58

I agree with Niekie. Before making any further comment to the ones that have been made, we should know where that specification comes from, or in other words, WHO wrote it.
Giovanni S. Crisi
Sao Paulo - Brazil

By Mauricio Ibarra (*)

Date 11-08-2001 21:24

It comes from bechtel specif, for structural welding use in mining industries, I do not have more info.
mie

By G.S.Crisi (****)

Date 11-09-2001 19:53

I've known Bechtel for nearly 35 years now and I've got a great respect for it.
I see two possibilities.
First. They have a good reason to preclude E7018 eletrodes from structural welding in mining industries, which no one of us has been able to understand so far. I'd suggest that you get in contact with Bechtel via Internet, telephone or ordinary mail, and ask them the reason. Years ago it was headquartered in San Francisco, Calif. If you don't know their address, go to the following site: www.yellowpages.com Once in there, search for Bechtel Corporation in the state of California.
Second. Having worked in engineering and construction companies for 35 years of my life before becoming a university professor, I know very well how they think and behave. It wouldn't be a surprise for me that E7018 is forbidden just because some time in the past they had a bad experience with it. Instead of making a thorough research for the reason of the bad experience and clear it up, it's easier to erase the eletrode for the years to come.
In any case, and unless some of us who attend this site has as answer, as we say in Brazil, "in the pocket of his vest", I recommend you to get in contact with Bechtel and find out.
Regards and good luck
Giovanni S. Crisi
P.S. Has Bechtel got a representative in Colombia? It would be easier to handle this question through him.

By - Date 11-09-2001 21:21

I must agree with Prof. Crisi, that the best people to enlighten you on the reason for precluding E7018 would be the company that wrote the spec.

As it is in the mining industry, I would hazard the following guess:

As the E7018 has iron powder in, it might increase the electrode's propensity to absorb moisture in highly humid and wet conditions as found in underground mining operations. This would lead to porosity problems when welding.

This is however only a wild guess.

Regards
Niekie