Weld overlay deflection estimate

[muld0020]

I was wondering if anyone has a general calculation for the expected deflection (caused by weld shrinkage) of a circular disk that has a weld overlay applied to it?

 

[prex]

Roark should have the formulae for bimetallic circular plates.
However, as always when treating weld distortions, the main problem is with determining the differential elongation of the two materials, that depends on so many parameters (weld speed, overlay thickness, width of each pass, preheat, and so many others...)

prex

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[muld0020]

prex -

Thanks for the help. I have looked at that formula in roark already. My question came from all the other factors you mentioned. I was hoping for something with a heat input factor, volume of weld deposited, or simplified general equation with a "fudge factor". I'm not sure an approach with a delta T in it would work (like roark) since the temperature is not known as the weld is being deposited and it is constantly changing as more volume of weld is added. Maybe someone knows of a "rule of thumb" approach...

 

[weldtek]

You didn't provide any specific information, but, there's so many variables involved it would be very difficult to estimate deflection. Obviously, the base metal type and thickness, and the overlay type and thickness are big factors, but so is the process. Some processes, like SAW have relatively high heat input, while others like GMAW-Pulse have much lower heat input.

 

[Christine74]

Heat input from the welding process is obviously important, as is the specific heat capacity of the disk, the coefficient of thermal expansion and thermal conductivity of the disk, and the disk's yield strength at the achieved temperature.

Sounds like it would be very difficult to predict, even if anyone had derived such a formula.

-Christine