my Buna-n (NBR) general purpose o-rings crack within 1 year in an industrial atmosphre, not in the sun but in contact with the air around it and some rain. O-ring is used to seal a lid of a box so it is under a bit of stress. Many small transverse cracks almost complete around the ring in...
I am investigating a severe SCC type failure in flanges of 316L used for only 10 hours on steam 30 bar , 300degC.
All innner surfaces are black (magnetite oxide?).
The 8 # flanges completely broke off (with typical branched scc type cracks)near the weld with a CF3M casting in the HAZ , however...