Hi Dear can u please explain me the relation between nace requirements and strength of steel, I know that nace has some restrictions for hardness and also I know that there is relation between hardness and strength but I can't find any direct matter for strength in nace !

Microeng NACE MR 0173 specifies correlation of hardness ( i.e, T.S in effect) with susceptibility from SCC under corrosive service environments - viz., H2S or Sulphide environment. NACE guideline specifies the limit to which materials used in specific environment from limit from hardness (indirectly T.S of materials used for such environment) and from prevention from SCC trends. If it is marine or off shore (oil & gas) the limit from hardness ( T.S) should be lower than < 210 BHN from likely suscpetibility from sulphide SCC. Hope this helps you C.V.Srinivasan August 5, 2010 Nishi Engineers Pvt Ltd India E-mail: nishi@vsnl.com >Hi Dear >can u please explain me the relation between nace >requirements and strength of steel, I know that nace has >some restrictions for hardness and also I know that there is >relation between hardness and strength but I can't find any >direct matter for strength in nace !

Thanks all our problem is this: we have sour service in some equipments of our unit. we have to use SA 302 Gr.B for some part of equipments, but steel manufacturer told us that he can't mention NACE conformity in material certificate because of high strength material. (he agreed that NACE requirements will be considered but he insist that he can't mention it in material certificate). I can't understand it , I think when all of NACE requirements are applied then there is no reason to disagreed with NACE certificate!