Ductile = Nodular right? Would the diff housing be of the same material? What applications would gray or white iron be preferred over ductile?
Anyways I got it welded up tonight. I setup the heater and let it warm up the knuckle/tube. Surprisingly enough, it held it right in the mid 80's - perfect. I first tried welding within the packaging preferred amperage (105) and was having trouble forming/pulling a puddle. I decided to up it to 120 amps (5 amps over recommended) and it worked quite well. quickly formed a puddle that I could pull for an inch or so then let cool. I was curious so I checked the temp right after I knocked the slag off and was surprised to see it was consistently in the 200-250*F range. I could touch it for a 2 count before it got too hot for my fingers. I thought that was interesting.
I then would flip the axle, check temp to make sure it was under 100*F, and weld another inch or so. Flip again, wait a few minutes for it to drop to 90-100*F, and weld again. It was surprisingly easy to monitor the temp, my the end of the night I had a decent 'feel' of what temp it would be at.
The rod itself felt like it was 'soft'. It didn't burn excessively quick, but it just felt different when pulling the puddle.
OK enough of the chit chat - on with the pics
initial temp check
pass side caster (without pinion angle set)
driver side caster
pre-weld
tacked up
welding process
DONE
Of course I only took pics of the decent looking welds. You can see from the finished product that its FAR from perfect. Its hard for me to start a weld cold, I'm used to burning things nice and hot. This whole assembly was welded cold, so that was an experience. I'll go in and take down the high spots with a flap disk. If I feel it could use a second pass, I'll do it. I used just under a half pound of rod, so I should be able to get another pass done if need be (I bought 1lb).