I would like to know the welding proceedure on 310 to 310 s/s 1/4"plate for a gas fired heater about 6'-0" in diameter and approx. 18'-0" long. I have fabricated 6 assemblies and the customer is starting to see cracks in the welds. My guys tig the inside with 310 filler rod in the inside and mig the outside with 310 s/s mig wire as the root pass and follow up with a cap pass with the same wire. I can't understand the reason for the cracking?Does anyone have a better proceedure?Thanks Murry
Reply:Originally Posted by MurryI would like to know the welding proceedure on 310 to 310 s/s 1/4"plate for a gas fired heater about 6'-0" in diameter and approx. 18'-0" long. I have fabricated 6 assemblies and the customer is starting to see cracks in the welds. My guys tig the inside with 310 filler rod in the inside and mig the outside with 310 s/s mig wire as the root pass and follow up with a cap pass with the same wire. I can't understand the reason for the cracking?Does anyone have a better proceedure?Thanks Murry
Reply:The exact location of the cracks might give you a hint. Are they at intersections between the can joints and the longitudinal seams? Another thing to consider is too high an interpass temp. Is there lack of penetration at the crack locations? A TIG weld on a six foot diameter can is a long and slow process. Why not wire feed on the inside then gouging to sound metal with a grinding disc on the outside. I am thinking a 1/8th vee prep at 60 degrees on the inside to start??? 310 has a LOT of carbon in it. Is there a chance that there is some carbide precipitation going on caused by high interpass temps? An 18 foot long can is going to stretch a lot when heated. Are there existing units in operation trouble free? An "expert" is liquid under pressure or someone who lives more than five miles away. :'))
发表于 2021-9-1 01:01:58