Bizzare Question with Stainless
Bizzare Question with Stainless
(OP)
So i have a bizzare question/ problem with some 316 stainless steel. I have two parts that connect together, than came from the same heat number. the larger part is corroded and is also harder (33HRC compared to its counterpart at 12 HRC) The smaller part however has become magnetized. The area that this part has come from is the only area we see difficulty with. We have had this occur before and to me it looks like CO2 corrosion occuring ( speaking of which does anyone have some good links for CO2 corrosion examples), but only on the bigger part. Ive done some hardness tests on what we have in stock and the smaller part is harder in some cases compared to the bigger part. Correct me if I am wrong, but doesnt stainless steel have a passive layer on the outside, which should reform if it is worn away? Is it possible since one part has been magnetized that a galvanic cell has been created. Any thoughts?





RE: Bizzare Question with Stainless
What kind of system in this?
First please re-check the hardness in RB.
The harder piece could be that way for a couple of reasons. It is probably work hardening, and there may or may not be any strain induced martensite. If there is none, then it would not play a role in corrosion.
I would focus more on the surface condition of the parts. Their roughness, cleanliness, and passivation. Yes, in normal oxygen containing systems stainless will naturally re-passivate. There are some things will interfere with this process.
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RE: Bizzare Question with Stainless
RE: Bizzare Question with Stainless
RE: Bizzare Question with Stainless
First of all, even the 92 RB sounds high for 316.
Secondly since the part broke it must of had a lot of load on it.
Fatigue? I tend to think of flow related issues.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Bizzare Question with Stainless