Effect of Rotary Swaging on Hardness

I'm not 100% sure, but I think the end of the pipe get softer, remember your cold forming the pipe, and by it getting softer it forms a better seal with the mating part.

but let's see what others say.

Rotary swaging cold works the metal, so hardness will increase in proportion to the % of cold work.

Given the proper strain hardening coefficient for the material and the amount of cold working strain fromswaging, this can be calculated. Here is a link:

http://en.wikipedia.org/wiki/Strain_hardening_exponent

milo "rubbing seldom makes things softer"

but then how to get the strength coefficient K?

i would rotary swage an alloy steel pipe of grade ASTM A335 P9. pipe has to be reduced from O.D.50mmx5mmthk to O.D.44mm and approx length to be swaged is 8 inches. how do i work out the increase in hardness in this case?

-sahil

Dear Sahil,

Please check the hardness of your work and refer chart for the strength. In case of carbon steel, there is direct relationship between hardness and strength. Also, Cracks developed due to work hardening should be checked before applying work loads.

Regards.