8620 vs 4320
8620 vs 4320
(OP)
I am looking to possibly replace parts using 4320 steel wih 8620 steel. I am interested in what changes I can expect in regards to impact strength, fracture chacteristics, and compressive strength if I switch from 4320 steel to 8620 steel. Will there be any negative consequences If I switch alloys? The parts are carburized to 60 Rc. These parts are under constant repeating impact so fracture and fatigue resistance will need to be good.
Are there any resources(books, websites, etc) out there that will help me in my decision?
Any help guys?
Are there any resources(books, websites, etc) out there that will help me in my decision?
Any help guys?





RE: 8620 vs 4320
Stulz-Sickles Steel is where I have purchased plate and bar from.
It will work harden to Rc60 so if you need to do much machining you'll need to look into a great grade of tooling.
ASTM A128 is a cast steel specification so there are foundries that can cast a part to reduce any machining.
It used for crushers and railroad switch gear normally.
I am currently making some parts from this stuff and it is tuff.
Hope this helps, David
RE: 8620 vs 4320
But 8620 typicall has 0.5% Ni vs. 2.0% of 43XX. Ni will give you excellent impact toughness. So maybe you won't have enough toughness, unless currently you have plenty to cut down.
RE: 8620 vs 4320
RE: 8620 vs 4320
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The charpy impact numbers are similar. The yield strength of 8620 is higher. Looks like a fair substitution.
Ted
RE: 8620 vs 4320
Hydrools I've been comparing the two materials and come to the conclusion that charpy values matter the most. Your post makes me more confident that I am looking at the right values to compare.
I am primarily concerned with impact and fracture resistance due to our parts experiencing cyclic impact. Charpy values is what I should be concerned with right? What about crack propgation? I know charpy values measure toughness and how resisant the material is to initial cracks but what happens when cracks and start propgrating? Would 4340 be more resistant to cracks propgrating?
RE: 8620 vs 4320
Ted
RE: 8620 vs 4320
rp
RE: 8620 vs 4320