Can “as-forged” material be certified to NACE MR0175?
Often my company is asked by customers to certify our forgings to NACE MR0175. It is my understanding from them that our competition (including imports), certifies to MR0175 without normalizing and consequently we are pressured to do the same. We have three presses, two are fed by gas-fired furnaces, and one is with induction heaters. The gas heat forgings are typically heated to 2,300 to 2,350°F and forged on a 900T or 3500T open die press in a tooling pot, then still air cooled to ambient. The forgings heated by induction are heated to similar temperatures but only a portion of a bar and the flange end is forged close to shape, then air cooled in still air. Customers can order these forgings in the “as forged” or “normalized” condition per SA105. My question is do we have to normalize the forgings coming from either forging process in order to certify to NACE MR0175? The problem is interpretation of NACE MR0175/ISO 15156-2:2003(E), page 17, Annex A, Paragraph A.2.1.2. The heat-treated condition “hot-rolled” is not clearly understood and competitors with similar processes interpret that if the entire raw material piece prior to forge, let’s call it a mult, is taken to 2,300 to 2,350°F prior to forge that this satisfies the “hot-rolled” definition. We have contended that our products need to be subsequently followed with a normalizing cycle after being fully cooled to ambient in order to be certified to NACE and that neither of the forging processes listed above satisfies the definition of “hot-rolled” process.
Hot-forged material does not meet the intent of NACE MR0175/ISO 15156-2, A.2.1.2a).
An exception to this statement is given in A.2.1.3a).
Other hot-forged materials would have to be treated according to one of the five other heat-treatment conditions described in Paragraph A.2.1.2 to comply with this standard.
As a consequence, ASTM A 105 material is acceptable in the “as-forged” condition not because it is equivalent to a “hot rolled” condition in A.2.1.2, but because it is a permitted exception in A.2.1.3.a.
This question is in relation to NACE MR0175/ISO 15156-2 Annex A.2.1.2
Reference: ISO 15156 Maintenance Panel Inquiry #2005-25