salt spray life of A2 stainless steel 5

[keluonuosi]

what is the salt spray life of A2 stainless steel? Are there any standards about this?

 

[blacksmith37]

What is "life" ?
Nominally a 13Cr that will show rusting and pits in a day.

 

[blacksmith37]

My bad, I was thinking "D"; A2 is 5%Cr (and 0.25 V , 1.00 Mo).It still rusts pretty fast.

 

[keluonuosi]

THKS.My customer salt spray life as per ASTM B117, and rusted after 24h,this they can't accept.

 

[TVP]

keluonuosi,

A2 is a martensitic tool steel, not a "stainless steel". It will rust almost instantaneously (less than 5 hours) when exposed to salt spray unless it has some type of corrosion resistant coating on it. You will need a different alloy or some type of coating if there is a requirement for significant hours of exposure to ASTM B 117 with no red rust.

 

[CoryPad]

Is it possible this is regarding A2 stainless steel fasteners according to ISO 3506? If so, then they can withstand neutral salt spray for a long time with only minor pitting.

 

[keluonuosi]

TVP,

A2 stainless steel is austenitic stainless steel, like 304 &304L

 

[keluonuosi]

CoryPad ,
THX!
Yes, It's follow ISO 3506.

 

[swertel]

Well, if nothing else, I learned that A2 is not just a tool steel from this thread.

--Scott

http://wertel.eng.pro

 

[blacksmith37]

This format can lead to poor assumptions like mine. When consulting on the phone I knew who I was talking to; "Stainless Steel" meant 13Cr to production , SS meant 304 to refinery, and SS meant 316 to chemicals (and SS meant something expensive and shiney to management).

 

[redpicker]

Well, if nothing else, I learned that A2 is not just a tool steel from this thread.

Me too.

(in general, I am opposed to "Me too" posts, but this time I think it's appropiate to let swertel know he is not alone)
rp

 

[keluonuosi]

Help~~~~

 

[CoryPad]

keluonuosi,

Properly produced A2 fasteners shouldn't produce visible red rust for a LONG time during a neutral salt spray test. If it does, then it is due to iron pickup from forming/cutting/etc. This test method isn't suited for testing stainless steel.

Regarding standards, I would review corrosion standards like those from ASTM and ISO:

http://www.astm.org/Standards/corrosion-and-wear-standards.html#G01.05

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_tc_browse.htm?commid=53264

 

[TVP]

keluonuosi,

As CoryPad stated, salt spray testing is not really used to test stainless steel fasteners like ISO 3506 A2 or A4. However, here is one example of some testing by a fastener manufacturer showing the corrosion resistance of Type 304 (ISO 3506 A2) after salt spray testing:

http://www.sherex.com/pdf/dw_whitepages.pdf

 

[keluonuosi]

TVP & CoryPad ,

THX!