Will powder coat baking soften 4130?

[Philrock]

I have some parts made of normalized 4130 steel that I would like to have powder coated. The bake cyle is 425 deg F for 8 minutes, then 350 deg F for 15 minutes. Will this amount of heating have any tendancy to soften the steel?

 

[unclesyd]

I doubt that your 4130 was tempered at anything below the initial temperature of 425F for baking the powder coating.

You will only soften 4130 if you heat the material above the tempering temperature used for the heat treatment.

 

[metman]

The standard process for normalizing 4130 would include air cooling in still air from the austenitizing temperature as the last step. This would in effect be a stress relieving cycle albiet there will always be residual stress and some spec's might call out and additional stress relief or what could be called a tempering operation. In any event, 425F would have neglible to no effect on softening of normalized 4130.