Welded Large HSLA collars

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I have a 6 foot piece of 3.5" OD X .625 wall 513 steel tube, nothing special, very weldable carbon tube.I have two collars that must be welded to this tube.Each collar is a 2" thick piece of T-1 (ASTM A514) HSLA steel about 10" X 10" square footprint.  These pieces are welded towards each end of the tube.Any problems with using an all around weld to make the joint?I am not worried about the operating services stresses, but more so the post weld induced stresses due to restraint of the collars and the all around weld.There is about a .050 gap between the collars and tube, the collars have a machined ID, where the tube is mill finish.Weld process is shielded arc, with a The wire used is Lincoln arc 712C .045" dia., the T-1 has a 250 degree F preheat call out. Any potential problems?Would it be better to split the collars and weld them as two haves - even though it's more expensive?Would this create less restraint and therefore less stress due to welding?Thank you
Reply:I don't think restraint will be much of a problem since the 2" thick plate is far stronger than the tubing, which is low-carbon steel and not likely to crack. I would personally use 7018-1 rather than flux core but that's just me.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:I'm with John. The 7018 is ideal for that set-up if  allowed.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:Originally Posted by blawlessI'm with John. The 7018 is ideal for that set-up if  allowed.
Reply:The E7018 isn't better mechanically.  But stick welding might be less hassle to setup if you don't have too many welds to make.  The fine ripple of a 7018 is like art to most welders.  The 100% CO2 FCAW welds always look a little lumpy to me by comparison. Originally Posted by zbudThanks for the inputs.I'm using the selected wire with 100% CO2 for maximum penetration.How is the 7018 better suited?easier to apply, better finished look, better properties?Thanks
Reply:Another issue is that the mfr's strongly recommend low-hydrogen welding processes for T-1 steel, even when it is welded to mild steel. 712C is listed as H8, which is acceptable but I would feel more comfortable with an H4 filler metal. Lincoln has a wire called 712A80-H which is H4 but is made for mixed gas, not 100% CO2. Most 7018's are H4.JohnA few weldersA lot of hammersA whole lot of C-clamps