Question: Sand Blasting Surface Damage
Question: Sand Blasting Surface Damage
(OP)
Anyone have data regarding the depth of the surface damage induced by sand blasting (using sand/slag/oxide, not the more esoteric materials like soda ash, dry ice, or sponge) carbon steel to remove adherent oxide (magnetite)?





RE: Question: Sand Blasting Surface Damage
What exactly are you trying to determine? We use grit blasting for boiler prep for NDT, turbine prep for NDT (except glass bead blasting to avoid removing material in blade root locations) and pipe prep for NDT. I have never seen in my 25+ years of evaluating tubes, rotors, blades, buckets, pipe and BOP systems any subsurface related damage, period.
RE: Question: Sand Blasting Surface Damage
" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke
RE: Question: Sand Blasting Surface Damage
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/
RE: Question: Sand Blasting Surface Damage
RE: Question: Sand Blasting Surface Damage
RE: Question: Sand Blasting Surface Damage
Regarding XRD work - Yeah, sure. I blew my available XRD budget when I bought a pencil last month and since the outage is over budget, I don't think I'll find some more shillings laying around.
The Ultra-Double-Secret method produced a visible cold worked surface layer (visible as plasticly deformed in an etched metallographic sample) that was less than 0.001" (actually, around 7µm and less). I reported this to our engineer (mechanical/project) and he asked the question "How does this compare with 'regular' sandblasting?" which is what generated this thread.
I've got a bead blasting cabinet here in the lab that I would experiment with, but was hoping for an easy answer from someone who'd already done this sort of thing.
RE: Question: Sand Blasting Surface Damage
Don't waste your time and effort on this. Grit blasting is what it is, and for boiler NDT all you need is to effectively remove scale down to white metal for UT. There is nothing beyond this unless your vendor is using rocks to remove scale