Material and Heat Treat condition of a Flexible Blade
Material and Heat Treat condition of a Flexible Blade
(OP)
I have designed a anti-roll sytem that in a new application of excessive travel, is now bending the blades that are part of spring rate used in the system. We originally used 4130 to 42C, then went to 4340 all the way up to 53 C and are still bending the blades. We tried making some out of 1095 and brought them to 43C and they snapped.
I need a suggestion of materials and heat treat to prevent to blades from yielding, without catstrophic failure.
I need a suggestion of materials and heat treat to prevent to blades from yielding, without catstrophic failure.





RE: Material and Heat Treat condition of a Flexible Blade
Don
Kansas City
RE: Material and Heat Treat condition of a Flexible Blade
Ted
RE: Material and Heat Treat condition of a Flexible Blade
I have not failed. I've just found 10,000 ways that won't work." — Thomas Edison
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RE: Material and Heat Treat condition of a Flexible Blade
How are you doing your structural analysis?
In your calculations, you know deflection. You need to calculate the forces, the moments and the stress. You have to use the equations backwards. The bending equations from the handbooks are based on double integration method, and are reliable for deflections of up to 10% of your spring length. You may have to seriously read up on this, or use a good FEA program.
Have you considered beryllium copper or titanium for your springs? These materials are equivalent to spring steel for strength, but they have lower elastic moduli. You can bend them more before they exceed their yield stresses.
When I design springs like this, they are statically loaded and I do not need to worry about fatigue. Your life is not so simple. It may be possible to design a steel spring for infinite life. Beryllium copper and titanium have lifespans.
RE: Material and Heat Treat condition of a Flexible Blade
Cheers
Greg Locock
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