17-4 h1150 3

[redmike]

Does anyone know of any failure problems for 17-4 h1150 stainless steel? We are looking at using it to replace 4130 nace for our threaded connections.

 

[TVP]

Just because it is "stainless" does not mean it is immune to corrosion. Make sure that the environment does not have too many Cl- ions and other corrosive species. Cartech has good information available from their website.

 

[NickE]

Also using stainless steels in threaded connections may cause troubles with galling.

 

[unclesyd]

We have numerous production components made from 17/4 PH SS H1125 that have to maintain fairly close tolerances over many production cycles. Each of these components have over one hundred 5/8" course blind threaded holes. We use H11 SHCS that are continually reused after each cycle of the component. These components require only an occasional Helicoil after a hundred or so cycles.
We have experienced an increase in hardness and a loss of ductility on some of the oldest components. These can be restored to the proper hardness range by an over-aging treatment.

We have other 17/4 components that are used in weak nitric service where we use Gr8 class 2 fasteners. We have no appreciable problem with corrosion or galling.

 

[EdStainless]

17-4 is a reliable alloy with extensive experience. You can get mechanical properties similar to your 4130 and with better corrosion resistance.
The alloy does require very careful control over heat treatment so make sure that your sources have good track record.

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Plymouth Tube

 

[strider6]

it depends on exposure and operating conditions.

S.

Corrosion Protection & Corrosion Control