Dry Ice Blasting of Alloy Steel Turbo Machinery Rotors

I'm aware of dry ice blasting for removing glue residue or paint. It freezes the glue residue to make it brittle and knocks it off with high pellet velocity. It also knocked the powder coat off the tooling where the jet blast got too close but did not seem to affect the metal underneath.

I was told by the guys at ColdJet that it's not abrasive.

We've evaluated dry ice blasting on optical components, didn't use it in the end because it offered no advantage over existing cleaning methods but there was no damage to glass, quartz or fibre optic lenses.

Belated comment on this thread - have been on holiday.

I have used dry ice blasting quite extensively over the years, specifically if the rotor and or stators are to remain in the casing. It is a very gentle cleaning method, but much slower than other abrasives (glass bead blasting for example), so no great advantage if all the "bits" are removed and can be transported to a blasting site.

I have used it on large compressor rotors, volutes and diffusers, steam turbine stator and rotor blading, gas turbines etc. The temperature change to the surface of the material being blasted is negligible as the pellets revert to the gaseous state almost immediately on contact with the equipment and cleaning is achieved by a combination of this rapid expansion, the kinetic energy of the medium and thermal shock between the surface contaminant and the equipment.

Thermal effects on the metallurgy of shafts, blading, impellers etc has never been of any to concern to any of the OEM's that I have consulted.

Dear All,

Thanks for sharing your thoughts and experiences.

At the time being, as a precaution, dry ice blasting was not used on compressor rotors as no reference and OEM recommendation was found for aforesaid material.

If someone in future experience dry ice blasting on compressor rotors with similar materials, please share your experiences.

Once again thanks for taking out time and sharing your experiences.

Greetings for the New Year.

Thanks for letting us know your final decision - so often posters do not do this which is frustrating.

I am amazed that you could not get OEM approval for this method of blasting. Cost is one of the few reasons that I know of that would preclude this method.

A320 is a low temperature material - 4340 (4140 with no nickel as close as makes not difference in this case) and A182 is 2.5 chrome 0.5 molly.

Neither of these materials are a problem when using a process that lowers the surface temperature of a compressor rotor more than roughly 10 to 20 degrees C during a normal blasting process, which is not sufficient to alter the metallurgical properties (I am without doubt not a metallurgist).