Rolled Bar Vs Forged Bar

[Karthik priyan]

Hai everyone,

IS there any literature / research material available on the difference between fatigue properties of gears made out of rolled and forged bar stocks? My purchase department is finding it difficult to procure forgings made out of closed die process. We already have forged bar stocks and the Purchase dpt is asking to use the forged bar stocks for making the gears. I, for sure know that closed die forging is superior but dont have much information on "Forged" bars. Pls help.

Thanks & Regards,
Karthik

 

[mfgenggear]

atlas of SN curves

 

[EdStainless]

What alloy?
Do you know anything about how it was hot worked? What was the reduction ratio?
Often the issue with bar is that it was not reduced heavily from the ingot and may not have as much structure refinement.

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P.E. Metallurgy