In oil & gas, I haven't come across any direct, metallographic inclusion content acceptance criteria. Some specifications, e.g. castings, will have NDT based acceptance criteria. Generally, for sour service, specifications focus heavily on chemical composition and steel making practices to minimise and modify inclusions which is then backed up with HIC testing for confirmation. For non-sour service, the toughness requirements generally force a clean steelmaking process.

Steve Jones
Corrosion Management Consultant

www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

I am surprised that API does not have a cleanliness requirement in their standards. Probably 7 or 8 years ago I sat in on a few API subcommittee meetings on a standard that they were working on for approval of foundries. They ended up including a cleanliness test to E45 even though the standard specifically states that it is not intended for use on cast materials. I think the standard was 20A but I have changed industries and don't have access to my notes on those meetings any more.

Bob

All of the requirements that I know of are in high strength/high fatigue applications like bearings and aerospace.
Finding guidelines for 'normal' applications is tricky.
The place to start is to by testing existing products so that you get a feel for what levels you are dealing with.

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P.E. Metallurgy

E45 only specifies the methods to test, and how to rate different type of inclusions. It won't tell you criteria to accept. Inclusions are driven mainly by the impurity chemistry, melting type and steel making process. It is unlikely to find a criteria based on sour /non-sour environment. I know, for medical implant applications, different alloys have different requirements. 316 SS and Co-Cr-Mo alloys, for example, have different requirements on inclusions, correspondingly these different requirements ask for different melting practices, and different control of chemistry.

Thanks every one
my client has insisted that the severity is Max 1.5 as per method D E45.The goods are Casing in several OD and in a number of our wells we are in region 3 (H2S) severity. Since the manufacturer has stated in their MPS max severity is 2.5.

Was 1.5 in the client's specification from the start?

Steve Jones
Corrosion Management Consultant

www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.