I have been doing some rebuilding and hardfacing of a loader leading edge. I rebuilt using wear plate, which was Bn 360 hard. All went well. I pre-heated and used stainless wire with Ar Co2 O2 mix (Argoshield Universal).
I then wanted to hardface both the welds and the face of the wear plate, with cross hatches, as it is "only" 360, whereas the LE is probably at least 500 Bn.
As far as I could see the above gas was OK.
The HF wire I used was 650 Bn "Cobalarc". 1.2mm. The smallest I could get.
I had a lot of trouble with "poking" where the arc was simply not working, so I had to weld very hot to make sure I had a smooth bead.
I found that welding without weave helped. This is actually recommended to prevent the hardface being diluted with the substrate, but the very hot (almost spray) weld of course would make this worse again, and is _not_ recommended.
I also found that I could get better results with a really short stickout. But again this is simply a hotter weld, and has the same problem. Normally, the stickout is a lot less sensitive, and can be used easily to give different weld penetration and bead build.
I was well shielded from breeze, and was using 5 out of a high of 6 voltage settings on the welder (say 200 of 220 A). It rarely gives me this trouble with other welds, and that's usually because of rust/dirt.
There was a lot of black soot on the weld; far more than usual.
I used a new 1.2mm nozzle.
I guess my question is, given that I was pretty careful about cleaning the job, grinding and brushing, what could I have done to help? Other gases?
Thanks for any help. Learning all the time.
***************************************************** Have you noticed that people always run from what they _need_ toward what they want?????