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Best Stainless Alloy for Potassium Hydroxide

Is there a stainless steel alloy that will resist corrosions when potassium hydroxide is present? Application involves submerging substrate with 140 °F, positive and negative 14.2 volts 30 amp. So far, T304 and T316 will not withstand this environment.

Michael Liu Taylor
specialty stainless steel distributor - Dallas, Texas
February 17, 2009

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First of two simultaneous responses --

Sounds as though you are using the stainless container as one electrode of your circuit. Then the problem is not the KOH, as any stainless or low alloy or plain carbon steel is not affected by KOH. The problem is the electric current which, on one half of the cycle, is causing the metal to dissolve. This is the principle of electrolytic etching and polishing.

It's not a corrosion thing, it's an electrolytic thing.

Perhaps you can use an inert electrode in the KOH instead, so that you can leave the metal container out of the electrical circuit completely.

Bill Reynolds [deceased]
consultant metallurgist - Ballarat, Victoria, Australia
We sadly relate the news that Bill passed away on Jan. 29, 2010.
February 20, 2009

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Second of two simultaneous responses --

I suggest contacting Allegheny Ludlum about their E-BRITE ® ferritic stainless steel (UNS S44627). It has good resistance to sodium hydroxide up to 135 °C.

Toby Padfield
Automotive supplier - Michigan, USA
February 23, 2009