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Letter 24123
Corrosion of precipitation hardenable
stainless steel
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We are supplying a manufacturer of connecting pins with 17/4PH
(AISI 630) type of steel bars. They are ground to his finished size
and tolerance. After part machining he sends them to a heat treatment
shop for precipitation hardening at 482°C for 1 hr in
vacuum.
Some of these parts appear after heat treatment to have a lightly
corroded surface.
Do you have any ideas what this surface corrosion could be and
where it could come from.
Best regards
Barrington Tennant
- Germany
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The oxidation is likely due to incomplete evacuation of the vacuum
chamber, or due to a less than perfect seal. Contamination on the
door seals can cause the latter. Also, make sure that the surface of
the stainless steel component is clean and dry, with no residual oil
prior to placement in the furnace.
Toby Padfield
- Michigan
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