303SE or 30323 Free Machining SS for fittings?
303SE or 30323 Free Machining SS for fittings?
(OP)
Does anyone have any experience/knowledge about using a free machining stainless steel such as 303SE (aka UNS 30323) for a pressure fitting (i.e. a check valve).
It's for pressurized liquid, up to 6000 psi.
The check valve I'm looking at is currently made from 304 SS and production wants to change it to 303SE for easier machining.
any advice is appreciated.
It's for pressurized liquid, up to 6000 psi.
The check valve I'm looking at is currently made from 304 SS and production wants to change it to 303SE for easier machining.
any advice is appreciated.





RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
Are there any other free machining stainless steels that would be acceptable?
Is there any documentation that substantiates not being able to use it? (I know its not listed as an acceptable material in ASME, but there are a ton of materials that aren't listed but can still be justified)
thanks again!
RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
Can you provide reliable resources, specs, etc, that forbid the use of 303 and 303SE ?
RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
Here it is:
4.2.2.2.3 Corrosion Resistant Steel Unstabilized, austenitic steels shall not be used above 700° F (371° C). Welded assemblies shall be solution heat-treated and quenched after welding except for the stabilized or low carbon grades such as 321, 347, 316L, and 304L. Service-related corrosion issues are common for free machining alloys such as 303, and these alloys shall not be used in applications where they can get wet.
RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
RE: 303SE or 30323 Free Machining SS for fittings?
We had issues with 303 due to the sulfide inclusions. We ended up getting rid of all 303 unless we could show we were at some% or less of tensile stress.
Can't share technical data within the company files, and could not find any public domain data to point to.
RE: 303SE or 30323 Free Machining SS for fittings?
In one of the places I worked we had a warehouse to stock for all materials before approval. Every batch was metallurgically tested according to the spec and compared to the C.O.T before approved for moving to the supplying warehouse.