Joining high impact strength parts with low impact strength parts
Joining high impact strength parts with low impact strength parts
(OP)
I have been asked a question that seems to have an easy, obvious answer answer, but is it this simple.
If I have two parts that have a reasonable Charpy impact strength ( "A" joules) loaded in tension and wish to connect them with another part with a lower impact strength ( "B" joules), is it sufficient to just proportion cross section the connecting piece by the ratio A/B?
Lets say you had grade 8.8 threads that you wanted to connect with a grey cast iron coupling. if the iron had only a 1/10th of the Charpy value of the thread, can you just made the coupling 10 times the cross section?
Ian63
If I have two parts that have a reasonable Charpy impact strength ( "A" joules) loaded in tension and wish to connect them with another part with a lower impact strength ( "B" joules), is it sufficient to just proportion cross section the connecting piece by the ratio A/B?
Lets say you had grade 8.8 threads that you wanted to connect with a grey cast iron coupling. if the iron had only a 1/10th of the Charpy value of the thread, can you just made the coupling 10 times the cross section?
Ian63
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RE: Joining high impact strength parts with low impact strength parts
RE: Joining high impact strength parts with low impact strength parts
thanks for your reply
If I want to ensure that such a system is limited by the threads in my example, surely if the coupling is very big in cross section it would not fail in an impact load that would fail the bolts??
My question s how much bigger in cross section? can you just use the ratio of charpy impact strengths?
Ian63
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Joining high impact strength parts with low impact strength parts
RE: Joining high impact strength parts with low impact strength parts
You never want to put threads into a low toughness material if impact is a concern, you are better off clamping that material.
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