Are Stainless steel fixings weaker than M/S in low temps? 1

[stendec68]

Hello, i am working with some one off designs for architectural replacement shrouds in a variety of materials all over the UK.
Therehas been concern expressed over using zinc plated or galvanized fixings due to corrosion in certain areas in Scotland and Wales either due to the cold winter temps or proximity to the sea.
It was suggested that stainless steel fixings were used to try to combat this, but I have learnt in previous jobs that stainless fixings can become weaker in cold temps than the M/S counterparts. galv / zinc plated or otherwise.
Is this incorrect or am I worrying about nothing?

 

[Metalguy]

Assuming the stainless is 304 or 316, it does NOT become weaker with cold. It also has VERY high toughness-(resistance to brittle fracture).

But it can be very susceptible to fatigue cracking, especially if it's annealed (soft condition-max. corrosion resistance).

 

[stendec68]

Thanks chief! We did some specials work on some ships in the arctic circle and the stainless turnbuckles and U shackles [316 if I remember]shattered under tension , we replaced them with Hot dipped galv M/S counterparts and they held true, but this was -25 degrees or more so you are right, I just wanted some confirmation.
I normally work with GRP and other fibre laminates now so am a bit out of touch with my steel fabricating days. Thanks again.

 

[Metalguy]

Thanks for the star!

But something isn't right. 316 ss is frequently used in its annealed state (non-magnetic), and isn't brittle at cryogenic temps.--like -200 deg.!

Perhaps your turnbuckles were 416 ss instead-completely different properties, but still a stainless steel.