N&T 4130 impact properties?

[Kipmet]

Hi all,

I work as a metallurgist and we've received an RFQ for 4130. The tensile requirements should be a cakewalk- 85 KSI UTS, 45 KSI yield, 15% elongation. My concern is the charpy impact requirements - 20 ft-lbs at -4°F. We do not have the ability to quench this size casting so it would be normalized at 1650°F, air cooled, and tempered at a temperature to be determined. The test material will come from separately cast keel blocks that will be heat treated along with the casting.

Thanks!

 

[MFAMET]

In order to enhance the impact energy, other than the concerns on TS and ductility, you could try to refine the grain size by minimizing the normalization time and maintain temperature not to exceed 1650F. you also could ask for a small amount of Ti or V in the liquid steel to get a fine structure.

 

[mfgenggear]

Farm out the heat treatment

 

[weldstan]

The requirements should not be that difficult to meet. Fine grain melting with .02% Al and or limiting S below 0.010% will definitely help.