Read an interesting datasheet on ACUBE 100 today

The datasheet on AMS 5918 (ACUBE 100) indicated that the ductility of the material is severely impacted from even a small amount of cold work : Cold Working

High strength levels can be achieved in ACUBE 100 alloy through cold working processes. It should be noted that a significant loss of ductility results from even small amounts of cold work. Taken from http://cartech.ides.com/datasheet.aspx?i=101&c=TechArt&E=341 on 10/28/2014

After locating the material specification in a cold formed bushing requirement, I was interested in what the AMS 5918 was. I was even more surprised after reading the above excerpt. The AMS 5918 is the warm worked variation (in certain cases, warm working can have undesirable precipitates occur). Warm worked materials have 7 to 30% Elongation and 10 to 24% Reduction of Area.  These low Elongation and Reduction of Area numbers indicate a stiffness or brittleness that would indicate fatigue and shock resistance may be an issue.

Wear and galling resistance is toted as primary benefits of the grade, but it has a very low galling threshold. Galling threshold is listed as greater than 20KSI. While the >20KSI threshold (per ASTM G98) is impressive when compared to type 316 which is >1KSI and 440C only attains 18KSI, it is also telling when MP35N has a threshold of 5KSI. I must note that NITRONIC 60 in the annealed condition (AMS 5894) has a threshold of >50KSI (primarily dictated by its yield strength, rather than an overall hardness achieved).

We perform hot, warm and cold forging processes in Tipton on our various equipment, so its always good to stay abreast of materials that are being utilized by industry.