Question about Music Wire Stress Relief

[l0aded]

I have done some research on the topic but came up with nothing conclusive. Is there a certain time frame after forming a music wire spring that is crucial in the stress relief process (either by presetting or by heat treatment)? I have seen one article done awhile back that came back inconclusive for stress relief by heat treatment but they only compared 5 minutes vs 24 hours after forming the spring. I am curious of the difference between presetting or heat stress relieving the spring within 24 hours vs 5 days+.

Also how much does the diameter of the wire matter for stress relieving by heat? Most guidelines layout 200-230C for 10-30 minutes but if the wire diameter is very low (~.012" to .014") can less time be used?

The music wire has no coating or finish (pre or post).

Thanks!

 

[israelkk]

Presetting is the opposite of stress relief, the process intentionally induces favorable negative residual stresses into the spring wire.

 

[l0aded]

My mistake, I am trying to lessen the effects of preset and was wondering if there is a time frame when presetting has a greater effect. My compressed height is fairly close to solid height in my applicaiton.

Also regarding the heat treatment, is there a critical time frame where it is more effective for stress relief or can it be done at any time after forming?

According to article:

http://www.dtic.mil/dtic/tr/fulltext/u2/a013826.pdf

The time interval after coiling and relieving is negligble.

 

[TVP]

I would not recommend less than 10 minutes for the thermal treatment time, even with your small wire diameter. In terms of time interval after coiling, there is not going to be any meaningful effect, as your reference notes.