Hi,
We are bound by contract documents that our shop and field welding are per AWS D1.1. I found out this morning that one of our erectors has been using 7010 electrodes to weld everything, which could range from structural framing angles on beams welded to vertical wall embeds, to stairs and handrails. 7010 is in the A5.5 low alloy classification, and it is my understanding that it is mainly used in high tensile API pipe applications. He may have a qualified WPS document for this, but I seriously doubt it. In my interpretation of Table 3.1, the 7010 would be prequalified to weld Group I to Group I, but can’t be used for Group II unless it has been qualified to do so. Our Group I base materials are A36 3/4” or less , A53B, and A500B, and our Group II base materials are A36 over 3/4”, A572 Grade 50, and A992. I haven’t gotten that in depth as of yet with exactly what has been welded with the 7010, but my main concern is that he may be welding to Group II materials, in which prequalified low hydrogen electrodes are required, and that by doing so, would cause the welds to be susceptible to cracking. Before I cause waves with this erector, I wanted to bounce this off you guys to see what your thoughts are. Just because I haven’t heard of or experienced this situation before, doesn’t mean that he's wrong and I’m right with my interpretation of the code, I just wanted some feedback from you guys before I either take the next step, or back off and let him proceed.
What do your contract docs. say? Usually anything structural is welded with low hydrogen electrodes. Check your documentation. Anything different require engineer approval.
Brian J. Maas
Check note 1, table 3.1. In general, if the filler metal matches the higher strength base material it is compatible. Otherwise go to lower strength requiements and weld with low hy-rods.
Check the contractor's WPS and PQR - no messing around. Do it!
This is a normal inspection attribute and per AWS D1.1 you are responsible for verifying the contractor's welding procedures and personnel qualification.
All welders must certify to the WPS.
Best Regards, Vonash.
AWS D1.1 Section 5.5.1.2 says :"Qualification of a welding procedure established with a base metal included in Group II of Table 4.1.1 shall be considered as procedure qualification for welding any other steel in this group, combinations within this group, or any other steel included in Group I."
This means that you require to have a new WPS for welding Group II base material whatever the elecrode that you use for Group I. And if you qualify new WPS for Group II base metal by 7010 then you will solve your problem.
Regards,
Tolga
Hi All,
In response to the post by Tolga, is it possible for a procedure to be qualified using a non low hydrogen electrode to weld A572 Grade 50 steel? Have any of you ever done so, or heard of this being done successfully? I have not had experience with this type of qualification and I don't know if it would be feasable. As I stated in my original post, I'm concerned about the cracking potential on the existing welds on A572 Grade 50 with these 7010 rods, and how well these welds might hold up in service. I guess we could perform testing on the field welds, but what about the possibility of delayed cracking? Any further comments would be greatly appreciated.
Hi
A while back we debated what should be done if a job was welded with "damp" rods. I believe your situation is simmilar. If the material type, restraint or thickness is of such a nature that cold cracking can take place, then a lot of inspection needs to be done to ensure that the welded connections are sound. If not, they should be removed and re-welded with the correct consumables.
Regards
Niekie Jooste
Fabristruct Solutions
swnorris:
I can appreciate your dilema.
Two many questions to be asked including:
1.) What was the preheat for the E7010?
[vs. the preheat for low-hydrogen electrodes in Table 3.2...]
2.) As noted by Niekei, the level of restraint and thickness?
3.) Condition of the E7010 elctrodes prior to welding?
[AWS A5.5-96, A6.11.4: "Cellulosic coverings for E(X)XX10-X and E(X)XX11-X classifications need moisture levels of 3 to 7 percent for proper operation." Here in CA the intent is to reduce hydrogen levels in welds, particularly at moment-resisting connections. DHC was one of several primary culprits during the Northridge Earthquake. Depends on your seismic zone...]
A.) PWHT could have helped some in reducing restraint and hydrogen levels.
B.) I think the typical mechanical testing (tensile, impact, bends) and NDT (RT/UT) will all be satisfactory for plates welded in accordance with the D1.1. Therefore running a PQR may not provide pertinent data.
HOWEVER: Long term effects of relatively high hydrogen levels may not show for some time and/or with help from Mother Nature in the form of seismic or "cosmic" forces, etc.
Hi DGXL,
There was no preheat on any of the welds, the material thicknesses range from 1/8" to 1", and the rods were not stored properly.
HMMMMMM!!! Does not bode well for the erector in my opinion. Hard to see how anything but the most welding knowledgeable SER would consider putting his stamp on that if he knew all the facts. Let us know how this works out. I have an erector that works for us that could probably use the warning!
Hi Doug,
One of our employees working in the field saw the guy using 7010 and reported it to me. I went to my boss and expressed my concerns. This morning, I asked my boss whether anyone questioned the field guy about the rods and the guy told our office that he wasn't using any 7010. My boss then told me that there's an inspector on site, and if he's using them he'll get caught. At this point, I really don't know what else to do except document everything that has been discussed. Needless to say, I am extremely frustrated.
Does your job specification state " E70XX Electrodes?
Yes but there are instances where these 7010 rods were used on A572 grade 50 and they are not low hydrogen.
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