welding Rebar to 316

[DSRED]

I was on a welding job welding 30mm rebar to 20mm 316 plate with multi run welds, we did a PQR. with pre heating only on the rebar around 70'c the next day we got a call from the lab where the dye penetrant test was getting done first saying that we have centerline cracks in the weld so we take the test again with the same filler 312 solid wire. again we get the same centreline cracks, so with have more welding engineer's in to help us with the problem now we have to options we use 312 but MMA or 309MO flux core totally different really good with both but got the better result with the 309MO flux core but kept the pre heat at around 70'c now all we use on dissimilar joints is 309MO flux core especially on the thicker material and when we weld plate to plate still a dissimilar joint we use a 312 or a 309 solid wire

not a question just wanted to share I found it interesting as I was the welder from start to finish on the job and got lots of interesting info of the welding engineer's



any comments on this welcome

 

[r13]

Suggest to repost on the "welding forum" to draw more interested parties.

 

[EdStainless]

I am not surprised that you had cracking with 312. It is med Ni high Cr so with dilution with steel it is really then a high C duplex. The 309 is much higher Ni which will suppress formation of high hardness phases.

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