Heat Treat of 17-4 PH (AMS 5643) H1025 ?

[mtnz]

Hi Guys!

I am working on a project and I am asked to heat treat 17-4 PH steel(AMS 5643) to H1025. What would be the best way to heat treat such a material ?

Thank you!

 

[MagBen]

AMS spec already specify heat treatment: solution at 1900F+/-25F, fast cool to <90F, then age at 1025F for 4hr. air cool. The supplier would normally did the solution anneal.

 

Your local heat treat shop will be familiar with this alloy; I suggest you contact them.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

I presume that you have mechanical properties that you have to meet.
The AMS spec allows you to re-age at the same or slightly higher temp if needed.
This alloy is straight forward to HT.
Some cautions.
If it was annealed in thick section and has been machined a lot then re-anneal would make sense.
If there has been any cold work done you need to re-anneal also.

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P.E. Metallurgy, Plymouth Tube

 

[mtnz]

Thank you for the information!

So for 17-4 PH (AMS 5643) H1025, we will have to heat treat them at 1900F +/-25 (In Endothermic gas furnace) and fast cool to <90F (Air Cool). Then put them in the draw at 1025F for about 4 hours? Is there a difference between aging and tempering? if then, what would be the difference?

Thanks!

 

[EdStainless]

The difference is the material, not the process.
5643 also has notes about allowed atmospheres and post HT cleaning.
And there are tolerances on both the temperatures and times.

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P.E. Metallurgy, Plymouth Tube

 

[mighoser]

I look at AMS 2759/3 for guidance. I’ve personally aged 17-4PH in air. 1025F for 4 hrs. If you don’t like heat tint they wrap it in 321 SS foil. If this is a production part then send it out for HT.

 

[mtnz]

1025 F 4 hrs in the gas furnace or in the draw where there is no other gasses (EX: Endothermic, Natural Gas, etc) ?

 

[EdStainless]

What is required for clean-up? Acid pickling? (with bake out afterwards)
The heat tint seriously reduces corrosion resistance, and mechanical cleaning is not enough.

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P.E. Metallurgy, Plymouth Tube