HELP! Need Brinell value near shaft center - 4150

[sprintcar]

Shaft is made from 4150 non-resulphurized steel, machined from a 11.5" (292mm) bar. The subject diameter is 7" (178mm) where we need to know the estimated Brinell hardness.

At the OD of this material the Brinell is typically 269/321. However, the information we have from the vendor stops at 8" (203mm) diameter with that Ultimate Tensile listed at 115ksi.

Since this part was machined instead of forged, the properties diminish closer to the center. What I need to know is approximate Brinell reduction at different diameters from the outside working inward.

THANKS!!!
I'll also post in Metal & Met Eng. forum




Timing has an awful lot to do with the outcome of a rain dance.

 

[Goahead]

The heat treatment of your shaft was not specified in the question. Hardness at the center depends on the rate of quenching. If the original diameter at the time of quenching was 11.5", hardness at the center will not change by machining it to 7".
It is not clear what you mean by stating that the part was machined instead of forged: also in forged parts properties diminish closer to the center.
If you could get a bar slice, you could actually Brinell hardness test at the bar center.
If hardenability is your problem you could probably obtain Jominy data for the steel in question or find published hardenability bands.

http://www.welding-advisers.com/