Storage conditions of E 7018 & Conflicts in it.

[Srinivas Engr]

Dear all,

I am in confussion?

What's called hermetically sealed packages?
According ASME section 2 c SFA 5.1, Table A3,
for E 7018, its says 140degree Celsius is enough for backing oven
conditions, when its removed from packages.
but some manafatures says 300-350 celsius.

according to Table A3, we can use after baking in holding oven by 140
celsius & with quivers in site. am i right?

Is it correct or not?

When E7018 is expsoed to air, then only we have to baking to 300 - 350
celsius according table A3.

is any conflict in this? r any wrong in this?

Pl clear me...

Thanks
Srinivas

[Srinivas Engr]

In above, its all about baking & oven baking, If any word r like
backing = Baking. Don't mind

[kianoosh zarrin naghsh]

Dear Srinivas, There is different from the backing of electrode and the holding of electrode. Backing is done when its container is opened or the electrode is removed from its container, but holding the electrode is done immediately after removing the electrode from sealed container or when the electrode is backed. Usually the backing is done in large oven, but the holding is done in portable oven for welders. Low-hydrogen electrodes for shielded metal arc welding conforming to SFA-5.1 and SFA-5.5 shall be purchased in hermetically-sealed containers or shall be dried at least 1 hr at temperatures between 120 and 150 before being used. Electrodes shall be dried prior to use if the hermetically-sealed container shows evidence of damage. Immediately after the opening of the hermetically-sealed container or removal of the electrodes from the drying oven, electrodes shall be stored in ovens held at a temperature of at least 120°C. Electrodes that are not used within 1/2 hr after the opening of the hermetically-sealed container or removal of the electrodes from a drying or storage oven shall be dried as specified above before use unless evidence is presented which indicates that the brand of electrode used may be exposed for a longer period of time without exceeding the maximum moisture requirement. Hermetically-sealed is equal to a container that protected, sealed and tightened from moisture, humid, water and … . The backing temperature for A5.5 E7018 electrodes classifications is 250-400, but for A5.1 E7018 electrodes classifications is 120-150 in brands.    Be Happy! --- On Sat, 9/4/10, Srinivas Engr <srinivas...@gmail.com> wrote:

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[DOKKU AJAY]

Hermetically sealed package : It's not vaccum packed and it is prone to absorb moisture. The extenet of moisture absorption over a period of time is given on the packing or on the consumbale data sheet / guide book. The recommnedation generally given by manufacturer is to bake and hold prior to use. One of the reason why baking is recommended is that, consumbales are stored in the manufacturers/traders warehouse for a long period and chances of moisture absorption is there.

 

Generall practice in industries:

 

1. Baking  of consumables for certain duration of time shall be done after removing from packing (Except for vaccum packing) as recommended by consumable manufactureres.

Note: Some Manufactureres also recommend that if consumbales are stored in controlled humidity and temperature atmosphere, then baking is not required and consumbales can directly be transferred in holding ovens. (Generally 120 - 150 deg. cent).

 

2. After baking, Holding of consumables in holding oven priro to use.

Note: Code only suggest / recommend the baking & holding conditions. Manufatureres recommendation must be followed.

 

There is a misunderstanding at your end . Please refer Table 3 in SFA 5.1 once again. It recommends the holding upto 140 deg.cent. and for baking 260 to 425 deg.cent for E7018.

 

3. If quivers are having analaog/ digital meter. It can be used as a holding ovens for the site. However, make sure that they are calibrated regularly. Generally, there are seperate holding ovens in which the electrodes are holded from which welders get the consumbales issued in quivers for use for certain duration (Approx 4 hrs). In this case, only ovens are required to be calibrated and not the quivers.

 

I hope your queries are cleared.

 
 

Dokku Ajay Kumar

---

From: kianoosh zarrin naghsh <kzarri...@yahoo.com>
To: material...@googlegroups.com
Sent: Sun, September 5, 2010 1:27:23 PM
Subject: Re: [MW:6872] Storage conditions of E 7018 & Conflicts in it.

[MAHANTESH LONI]

If your using electrodes which are vaccum packed, no need of baking. Electrodes are packed in normal packing then you need to follow manufacturers recommendations, code only gives minimum requirements.

 

Regards\

Loni 

[Tran Ngoc Dan]

Hi,

Normally E7018 is packed with carton in that case it needs to be baked to ensure that humid content is minimum. The recommend temperature is 300 to 350 Celsius degree and 1 to 2 hour. The higher temp. the shorter baking. The purpose of baking is release humid it means that if electrodes expose to the environment more than 3 hours (not in portable dryer kept in 50 Celsius) they need to re bake and not more than three cycles.

Another options for EXX18 (E9018 / E10018 ...) , electrodes is packed in hermetically box (not vacuum) with small  amount. In that case Exx18 - yn 4HR is the code name. With this type the baking is no need (if you believe that no damage being on the box) and of course electrodes remained shall be baked for the next use.

In the case that electrodes keep in storage (50 C degree) it can re-use without re-bake.

Hope that it can help

Dan TN     

[sethurama lingam]

Dear Mr.Loni,

I agreed your point that vacuum packed low hydrogen electrodes will be used directly without baking , directly or transfer to quiver.How much time it will open to atmosphere?

also above discussion going with hermetically sealed packages(air tight packages) not for vacuum packing.

Regards,
PSR