Welding A572, Grade 60 1

[matschka]

I have a contractor that will be welding 0.50in. thick A572, Grade 60 plate that has to be welded to itself, to A36 and to UNS S3210 (unassigned)Duplex SS material.What precautions should they take when welding these materials. What welding rod should they use.It looks like 80ksi filler material should be used, preheat min. 50 F.

 

[metengr]

Welding A 572 to itself and to A 36 carbon steel with the thickness stated above- minimum preheat 70 deg F, using SFA 5.5, E7018 H4 weld rod (SMAW process). The specified minimum YS for this rod is 60 Ksi. Keep the interpass temperature below 600 deg F.

Now for the A 572 Grade 60 to the duplex, you need to use SFA 5.4 E309MoL weld rod. Minimum preheat as above, and keep the interpass temperature below 350 deg F.

 

[Mr168]

What is the material application and code of construction?

I've been dealing quite a bit with these specific materials as of late, and various requirements and specifications, depending on project and industry, can drive you towards consumables other than those that metengr has suggested.

Depending on code, there are some prequalified procedures that can often be taken advantage of using 80 series electrodes.

Additional precautions can also be taken based on whether any supplemental requirements for the duplex are invoked.

 

[Duwe6]

Please don't use 80-series filler. May cause problems, especially cracking if small root passes are made in cold weather.

metengr's recommendations will develop the full strength of your 60-series material. He has given you very good advice.

 

[Mr168]

Duwe6: Please take a look at the AWS material groupings. If the OP is being driven by structural codes (D1.1 for example), and he or his contractor intends to use prequalified procedures, he would be required to run an 80 series filler (such as a Ni1) when welding the A572-60 to itself (Group III to Group III). For the dissimilar carbon steel welds, then I would agree with the 70 series recommendation.

I've also been pushed to 80 series wires with processes other than SMAW when certain impact requirements were invoked that a 70 series wire couldn't meet. All dependent upon the application it's being applied to.

 

[Duwe6]

For AWS D1.1 -- Prequalified WPS's, Mr168 is correct: Use 80-series filler, as per Table 3.1

For a WPS that you will be making a PQR coupon for, like all ASME [or for welding w/o a WPS] metengr and I are correct. Stay away from overmatching filler to basemetal. You will have cracking start at preheats that would have been sufficient with a matching filler.