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my sister is doing a project on moly-steel (steel combined with molybdenum). It is supposed to be used in engines. Do you know if the A-10 uses moly-steel in its engines at all? If it does, what other info do you know? anything would be helpful, thanks

I can tell you it's probably tough to machine. Moly is generally added for strenth, though I'm not sure if it's ductility or hardness.

Someone here has the designation for the engine itself, and that can give you alot more info.

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thanks, do you know who has the designation

The engine designation? Its a TF34-GE100. I would assume that it has Moly in the engine but I couldnt tell you where. There's bound to be an engine troup lurking around somewhere here.

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Edited by - m&m on Jan 27 2006 8:16 PM

Titanium these days is the material that First fan and Compressor Sections are machined from. Some Stators have other material properties Depending on what section they located in the engine.

Heat and expansiion is key here on determining the material, Processing and material expansion tolerance. Steel Molbednum-disulfide is what is impregnated onto the surface, after they have been Machined, Shot Pinged, Extrude Honed then they receive the moly then heat Treated. It is quite an involved process.

Some other type of metals go Through Dye penetrant inspection and passivation to deteect and remove purities.

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Thanks a lot for the help guys, I really appreciate it.

Just to clarify something there is no 1st Fan on the TF-34 only a single stage fan.

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I'm refering to General Turbine Engine Design. Not specific to the TF-34

"The greatest pleasure is to vanquish your enemies, to chase them before you, to rob them of their wealth, to see their near and dear bathed in tears, to ride their horses and sleep on the white bellies of their wives and daughters."
-Genghis Khan

_________________
\"A good plan violently executed now is better than a perfect plan executed next week. \"

George S. Patton

Fair enough, but do you think that the TF34 uses molysteel

The Moly is a treatment to the Titanium, that is then Heat-treated. Which is part of the impregnation process. Think of it as bondo for car except, that the bondo is absorbed into the vehicle. It helps the Titanium blades resist wear.

"The greatest pleasure is to vanquish your enemies, to chase them before you, to rob them of their wealth, to see their near and dear bathed in tears, to ride their horses and sleep on the white bellies of their wives and daughters."
-Genghis Khan

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\"A good plan violently executed now is better than a perfect plan executed next week. \"

George S. Patton

Hell I just learned something new too, Another good day<img src=icon_smile_approve.gif border=0 align=middle>
Thanks Mudd.

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Having a doctorate in Turbine engine design. Is some info in my head i could do without....

Don't think i'll ever return to that industry.... Way too burned out.



"The greatest pleasure is to vanquish your enemies, to chase them before you, to rob them of their wealth, to see their near and dear bathed in tears, to ride their horses and sleep on the white bellies of their wives and daughters."
-Genghis Khan

_________________
\"A good plan violently executed now is better than a perfect plan executed next week. \"

George S. Patton

Airknight,

I was a TF34 engine Logistics Manager at Kelly AFB for 16 years before moving to Satellites but I did some checking and, from what I learned, there are no Moly-Steel parts on the TF34. The original TF34-GE-100 engine was modified to the -100A in the 80's per the Hot Section Life Improvement (HSLI) modification. This made changes to the stage 1 HPT blades, transition liner and a few other areas. We actually increased red line temps and life limits. Now there is a program in the works to modify the engine to a -100B by using parts from the civilian version of the TF34. The TF34-100B upgrade provides 15% to 30% more thrust for the A-10. This upgrade changes approximately 35% of the parts in the existing engine, will include a new fan based on CF34-8C design, upgraded turbine section materials for higher temperature operation at key mission points, a digital fuel control which will permit fan speed control, and a number of performance and durability upgrades to maintain desired thrust and life objectives. From what I understand, all the AF needs is the $$$ to do it. Personally, I would like to see this happen as the increase in thrust is the main thing Hog drivers have always wanted. Guess we'll have to wait and see what happens.

Engineguy

Might there be moly in some of the bearings in the engine?

No steel I know uses Molybdenum as anything but a hardness and strength alloying agent. So called "superalloys" which seem to use more of it than the commonly known "Chrome-moly" steels which are found all over, even in bicycle frames. An iron alloy example would be A-286. a nickel alloy is Inconel or Waspaloy. Alloy 188 is a cobalt based metal. I don't know how much molybdenum is in these "hot" alloys, but it isn't much. There is at least one stainless steel that has molybdenum in it like PH15-7Mo. An intermediate alloy steel with Mo in it would be called 5Cr-Mo-V which also has chromium and Vanadium as alloying agents. By far, the most popular steel with Mo in it is AISI 4130. This is the one commonly called "chrome-moly". It is cheap and can be heat treated to high strength, but it is not considered a "hot" alloy. Google the steels and superalloy names that I mention and you will get more info than you need.

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