Titaniums heat cycle resistance?

[gixrman]

Can Titanium withstand 16000 deg. heat cycles for any period of time? This is for a Turbo housing bolts that secure the turbine housing to the exhuast manifold. How long will it last before material failure?

 

[btrueblood]

You slipped a decimal point, also, is that C or F?

In any case, in either scale (C or F), no: all the Ti alloys are within or above their annealing range by 1600 F, and will be useless as fasteners at that temperature. Most Ti alloys have useful strength only up to 800 F or so. Use a high-temperature "superalloy".

 

[TVP]

As btrueblood noted, no Ti alloys are capable of providing fastener strength levels at 1600 F. About 1100 F is the temperature limit for most Ti alloys. Are you sure that the fastener temperature really reaches 1600 F? The usual alloys used for exhaust system fasteners are A-286 (Type 660) or Alloy 718, but they are usually limited to 1200 F exposure. Waspaloy (Type 685) is used for applications over 1500 F. The following references may be of use to you:

http://www.spstech.com/aero/tech_support/pptdir/Standard_Fastener_Alloys.pdf

http://www.spstech.com/aero/prod_lit/superalloy_brochure.pdf

http://www.specialmetals.com/automotive.htm

http://www.techalloy.com/News/Exotic materials.pdf

http://www.cartech.com/news/coldforming_frick_part2.pdf

 

[gixrman]

Thanks for the repleys. Sorry I didn't state C or F, it 1600F and I base that off a Exhuast Gas Temp. gauge.

 

[CoryPad]

The gas is at 1600 [&deg]F, but the part is lower than that. You need part temperature measurement (e.g. thermocouple) or computational analysis (e.g. Computational Fluid Dynamics) for this problem.

Regards,

Cory

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