Instructions on Heat Treating 17-4ph no discoloration permitted

[jeffg35]

We are a CNC machine shop trying to heat treat 17-4ph stainless valve parts to H900 condition. We have been trying different things but the parts are consistently coming out blue. We need a expert to give us instructions on the steps we need to take to stop the discoloration. I would appreciate any feedback on this matter.

Thank-you
Jeff Gerling
General Manager

 

[TD2K]

Jeff, you'll likely get better response posting this in one of the materials forums if you haven't already.