approximate expected hardness profile 12" diameter normalized 1045
approximate expected hardness profile 12" diameter normalized 1045
(OP)
A supplier's rep has raised objections to a minimum hardness requirement (150 BHN) on a 12 inch diameter bar of 1045 turned down to about 4 inch diameter. Their wording is awkward as right off the bat it seems to claim we require EQUAL hardness, not minimum.
At any rate, does anyone know of sources for information about hardness profiles generally achieved or realistically acheivable on large normalized bars?
thanks
Dan T
At any rate, does anyone know of sources for information about hardness profiles generally achieved or realistically acheivable on large normalized bars?
thanks
Dan T





RE: approximate expected hardness profile 12" diameter normalized 1045
I use practical data for metallurgist
it can be down loaded for free from Timken
look at page 45,Harden ability chart for 1045
Mfgenggear
RE: approximate expected hardness profile 12" diameter normalized 1045
You are either going to have to accept the risk yourself, or pay to have the material tested and agree with the supplier that the results of those tests will qualify the material hardness.
In reality, there is not much risk. If the chemistry is correct, and you have normalized material (not annealed), then you should be well above 150 HBW. That is, if you had to meet a 150 HBW maximum hardness, I doubt you could get them to agree to that, either. But, from your supplier's position, why should they accept the risk for something they cannot control?
If I needed to mitigate any risk, I think I would ask for surface hardness (they should be able to provide that at a minimal cost) and if it at least 187, have a mid-radius hardness and accept the material if it was 163 HBW or higher. The hardness should not change much from a 6" diameter to a 4" diameter, and it is pretty hard to mess up those instructions.
rp
RE: approximate expected hardness profile 12" diameter normalized 1045
According to the Timken harden ability charts the hardness changes rapidly.
please see link below.
http://www.timken.com/en-us/Knowledge/engineers/handbook/Pages/default.aspx
I would turn the bar near net size then would heat treat to the required hardness.
6" to 4" the hardness will change. then finish machine.
or am I viewing the charts wrong.
your comments appreciated
Mfgenggear
RE: approximate expected hardness profile 12" diameter normalized 1045
Mfgenggear
RE: approximate expected hardness profile 12" diameter normalized 1045
My concern would be on internal soundness of such a large bar. How is it produced? What is the reduction ratio from ingot? Carving a 12" bar down to 4 inches is pretty drastic and the center is likely to have shrinkage voids, discontinuities, and other imperfections that could cause problems; 4 inch diameter is only two inches from the center, and that's pretty close. If it's a forged bar from a 36 inch ingot, you're probably OK, but a rolled bar from a 20 inch ingot is likely to have issues. Whether or not these soundness issues would affect the performance, I have no idea (no info on the application).
rp
RE: approximate expected hardness profile 12" diameter normalized 1045
thanks for all your inputs
Dan T