music wire heat treatment A228 1

[cubedweller]

I am playing with a zinc coated music wire. I was told 500 deg for 1hour for heat treatment but that seems kinda long. Parts have very low mass and wire size is about 0.040". any other recommendations from your experience?

 

[israelkk]

This is not a heat treatment. It is a stress relief. Music wire doesn't need any heat treatment the wire is already in the spring temper condition. If the wire is already coated you may pass the stress relief. It is mainly done to avoid hydrogen embrittlement during coating and sometimes relief residual stresses as the result of the coiling. The only part in your spring that is not coated are the wire ends where you cut it.

However, 1 hour is not a long time if you treat a large batch of springs.

http://israelkk.googlepages.com/home

 

[koza19]

Israelkk is correct you do not heat treat this material. First is the material a pre-plated wire or a post plated wire? Pre-plated means that the coating is applied to the material prior to forming. Post coating means springs are coated after being formed. If it is pre-plated you should stress relieve after forming, this is to remove any built up residual stresses from forming the spring. Proper temp and time is 350 deg F for 1 hr. If the material is post coated then you should stress relieve the material after forming but at a temp and time of 500 deg F for 1/2 hr.

 

[cubedweller]

Ckozka, my material is pre-plated via hot dip galvanizing process. I have a copy of SMI Handbook of Spring Design. It says that a temperature range of 375 to 450F is suitable for music wire and your recommendations are fairly in line with this book. I have about 7pounds of parts to stress relieve. Sorry for the confusion of my broadened usage of words "heat treat". I am seeking a stress relief process afterall. Can you tell me more- why would I not wish to stress relieve at the higher temperature, say 500degF? Have you any direct experience with this material? Mine is obviously limited. My original posting for 500deg/1hr was from conversation I had with local manufacturer of springs but maybe I did not mention the zinc plating. I thank you kindly for the dialog.

 

[TVP]

Heating above 450 F will reduce the strength, both static and fatigue.