A New Powdered Steel; AR RPM9

[jimmontg]

It is made in China as it's a budget steel in the new CJRB Ria folder knife at around $55-$65 range. On the Cedric & Ada Gear and Outdoor video channel on YouTube he made 250 cuts on 10mm thick sisal rope after putting a razor's edge on it. The folder he had the lock had a very weak lock up and he fixed it up, but he didn't trust it saying to be careful as the knife is thin without a lot of material to lock up against.

Now the composition of AR-RPM9 is, 0.9% Carbon, 18% Chromium, 1.0% Molybdenum, 0.45% Manganese, 0.1% Vanadium, 0.30% Cobalt, 0.2-0.8% Silicon, less than 0.40% Nickle. So although I'm not a metallurgist it held an edge almost as good as D2 with a good heat treat. I will guess the 1% Molybdenum gave out some Moly Carbides with the Chromium and Cobalt added in. Since it's a particle blown grain will be fine and the Vanadium might add a little grain restriction too. Anyone with more knowledge of metallurgy is welcome to add your two cents worth as two cents worth is about all I know. I'd be interested to know what the 0.30% cobalt does.