3%Cr 1

[andysf]

Does anyone have an idea of how (if possible) to get 42-50HRC, 8J impact and 1200-1400MPa UTS from a material with 3%Cr, 0.45%C & >1%Mo?
I have thus far managed to achieve the hardness, but approx. half the required UTS with a hardening/tempering approach.

 

[arunmrao]

Please provide, part description and section thickness details,they will be helpful . Also, the quenching media used and tempering cycle please.

 

[EdStainless]

Sort of an S7, or high Cr 4140.
With a good low temp temper, say 450C, you should have 1200.
If you made hardness then you made tensile, my hunch is that you didn't get a good test because the material has so little ductility. Any twist, misalignment, or roughness of the test specimen will throw off the readings.

Looking at data for similar alloys shows that these properties are reachable.
Look at your heat treat and testing methods.

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Plymouth Tube

 

[andysf]

It's a clinker hammer, approx 6" max thickness. So far 930° air cool, tempered at around 550° air cooled.

 

[arunmrao]

Clinker hammer,on the wear surface you could hardface them and get a better life and output, rather than building Cr to 3% .What is the present practice for clinker hammers. Sandvik, and few others are providing cast composite solution . They perform well and are economical in the long run.

 

[TVP]

I don't have any information immediately in front of me, but 930 C may be too high for good toughness. You want to austenitize as low as possible, so check if 850-900 C is possible.