stainless welding consumable for dish head forming
stainless welding consumable for dish head forming
(OP)
Hi guys.
I have a project stainless Hooper, now for the dish head cap, i used welding electrode E308-17 and on the other weld side SW-308L CORED for flux core welding with complete joint penetration material 304L. after the weld process we undergo dye penetrant testing and it goes well. now ready for the dish head forming which will go massive pressure for forming and spinning, all the weld joint, CRACK.. can anybody tell me what happen, maybe due to the stress load of the process for the dish head forming or the consumable is the problem. thank you in advance...
I have a project stainless Hooper, now for the dish head cap, i used welding electrode E308-17 and on the other weld side SW-308L CORED for flux core welding with complete joint penetration material 304L. after the weld process we undergo dye penetrant testing and it goes well. now ready for the dish head forming which will go massive pressure for forming and spinning, all the weld joint, CRACK.. can anybody tell me what happen, maybe due to the stress load of the process for the dish head forming or the consumable is the problem. thank you in advance...





RE: stainless welding consumable for dish head forming
RE: stainless welding consumable for dish head forming
Flux cored is not known for making the cleanest welds.
How thick is it?
What was the microstructure of the welds and HAZ?
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P.E. Metallurgy, Plymouth Tube
RE: stainless welding consumable for dish head forming
RE: stainless welding consumable for dish head forming
RE: stainless welding consumable for dish head forming
RE: stainless welding consumable for dish head forming
What was your UT standard? Take a piece of 12mm plate and drill a 0.25mm hole in the center in from one edge.
You also need to look at how the weld cools. Make sure that you don't have any center line shrinkage or cracking. What is your estimated FN of the weld?
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P.E. Metallurgy, Plymouth Tube
RE: stainless welding consumable for dish head forming
Where is the root of the weld, on the inside or outside of the formed head (in compression or tension during/from forming)? Was the root back gouged and rewelded? Is that crack essentially at the low spot/line btwn. two convex beads of weld? That’s a little bigger stress raiser than the unground (undercuts?) out near the outer edges of the two welds. How many passes was this weld? Let’s see a few more photos; two showing the next 12-16" of weld length to the left & right of the crack; and one showing the weld and crack location on the entire head; enough of the head so we can see its general location on the head.
RE: stainless welding consumable for dish head forming
Guys thank you for the idea now probably i can now locate the root cause of this failure. The root weld is out side of the form head, so it is in the form of tension while the bevel is in form of compression. Does the root of the weld has effect facing in/outside the form head? yes back gouging is applied to the other side of the weld. UT test is standard using the 70 degree probe angle. anyway guys thank you so much for your time and response appreciated it much...more power.
RE: stainless welding consumable for dish head forming
As mentioned, what acceptance criteria was applied and did the UT tech calibrate on a stainless steel calibration block? Passing UT does not mean the weld is a picture of perfection. There is no such thing as a perfect weld. The weld represent a metallurgical discontinuity. The mechanical properties of the weld may meet code imposed minimums, but they are still likely to be different than the base metal.
Having welded for more than twenty years before doing what I do now, I know that welders have a tendency to leave traces of the root intact while back gouging with the thought they will "burn it out" with the next bead. As a UT technician/Inspector, I can tell you that doesn't happen. Those traces of the root end up being traces of incomplete fusion by the time the joint is welded.
Best regards - Al
RE: stainless welding consumable for dish head forming