Mechanical Properties

Think about what yield means. Your yield values are certainly under the required ones. So if I would be customer I would reject this as well unless you can explain why this material used still is deemed to be suitable as per the application (which I dont know).

The simple answer seems to be that your material was outside specification - and it might be as simple as the reviewer taking the easy way out.

However it is also true that the complete specification of a material is more than just yield or ultimate tensile strength. While you have mentioned composition other properties or qualities can be important too and these include grain size or structure -both of which are implicitly non-conforming if the tensile strength is out of range. All of these have implications in respect of stress corrosion performance, notch sensitivity and strength at low temperature. A deficiency in any of these areas would be a good reason for rejection in a demanding application.

Dear Mr,Trevorm

Can you tell me clearly..what are the reasons are there to reject the material in this kind of issue.Can you tell please?

I doubt the problem were the yield and tensile strengths. You mentioned that, as shown in the MTC, the yield & tensile are higher than the minimum requirement of EN10025, exceeding the minimum doesn't mean it exceeded the limit. You said the chemical properties complied within the limits. You need also to check the CE, impact temperature and energy value whether it complied with EN10025 requirement. Was your client was exactly looking for S355JR or you were supplying this steel grade as an alternative?

I think your client is suspecting MTC provided by you which are out of range EN 10025 standards.in my respective apart from chemical composition ,mechanical properties are also more valid.

you can approach your customer reason for his rejection and in the mean time also you can enquire suitability with vendor provided MTC would have thorough experience related field.

Trevor is right, there is much more than material yield on the material property. With the increase in yield and tensile, elongation is usually compromise, What is your elongation? And what is your charpy test result? Would it be all comply with?

Clearly the checking of the tensile properties at the supplier has not been carried out properly or the material would not have left the mill. In that case how can you trust anything else on the certificate?