7.82% Ni in 304 bright bar 1

[arunmrao]

I have received some 304 grade bright bars. The heat analysis given by the manfacturer is 8.02% Ni,while a product analysis carried out by us yields 7.82% only. Cross testing in other labs,doing wet analysis yields same (7.8%) results. I know for castings there is a standard guideline (ASTM) permitting such deviations for product acceptance.

Is there a similar acceptable guideline to qualify this material as 304.
Currently this material is identified and quarantined,before any further damage occurs.

Any help in this regard is duly and thankfully acknowledged.

 

[kenvlach]

For 304, ASTM A666 gives the range as 8.0-10.5% Ni which also must conform to applicable requirements of A484/484M.

ASTM A484/A484M,
"6.2 Product Analysis -- When required, a product analysis shall be determined in accordance with Test Methods, Practices and Terminology A751. The chemical composition thus determined shall conform to the tolerances shown in Table 1.
6.1 Heat or Cast Analysis -- The chemical analysis of each heat shall be determined in accordance with the applicable materials specification and Test Methods, Practices and Terminology A751."

Table 1 of A484 specifies tolerances over the max. or min. limits of the product specifications such as A666. "...it does not apply to heat analysis."
For nickel with an upper limit in the range 10.00 to 15.00%, incl., the tolerance is 0.10 max. (below lower limit or above upper limit).

So, heat analysis limits are 8.00-10.50% Ni,
product analysis limits are 7.90-10.60% Ni.

 

[arunmrao]

Thanks kenvlach and a star to you.

 

[EdStainless]

I would cut a slug and ask the original mill to certify the chemistry. To be honest there aren't many people that I trust to run stainless chemistries.
Yes, 7.90 should be the bottom end.

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[kenvlach]

I erred in reading Table 1 Product Analysis Tolerance in ASTM A484/A484M.
Corrected:
For nickel with an upper limit over 10.00 to 20.00%, incl., the tolerance is 0.15% (maximum below lower limit or above upper limit).

So, heat analysis limits are 8.00-10.50% Ni,
product analysis limits are 7.85-10.65% Ni.

I apologize. EdStainless, please confirm.

 

[EdStainless]

Ken, I checked that you refered to the correct spec and then didn't bother to check the value.
Yes, the table says "upper limit or Maximum of Specified Range".
The correct tolerance value is 0.15%.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[arunmrao]

Thanks once again kenvlach and ed. It has ben a great help. I have informed the vendor that the consignment is rejected.