From wcrahen@jlab.org Thu Jul 22 10:26:09 2010 Date: Thu, 22 Jul 2010 10:26:09 -0400 From: wcrahen To: Tim Whitlatch , Alexander Somov Cc: George Biallas , Robin Wines , Paul Brindza , Eugene Chudakov Subject: Answers for tagger material/processing questions I spoke with representatives from several foundries, heat treaters and a metallurgist we have on staff here (Andy Wu). The comments/recommendations were as follows: 1) Due to our long (15 hours or greater) annealing cycle, annealing in regular atmosphere would have too high a risk in creating a thick diffusion layer (Hydrogen). Other contaminants could also penetrate. *Recommend sticking with the vacuum annealing.* 2) The one known vendor with a vacuum furnace large enough (Solar Atmospheres) would charge $0.45/pound of material, so annealing would cost about $70K. a cost for annealing in combustion atmosphere is about $0.20/pound, so the difference in cost is $39K. Given that the project scope is ~$600K, saving 6.5% on total project cost and possibly having a problem magnet seems an unacceptable risk for the benefit. 3)Given the size of our plates and the total material involved, our magnet will require a special rolling and heat in any case. The vendor that provided the material (Pioneer Steel) for the 4 meter dipoles tells me that *there would be no difference in cost for our 1006 variant versus 1010. *4) My reading on processing steel for large rolling reduction (or forge reduction) to remove voids and inclusions indicated that the steel should be "*fully killed"* (additives to remove oxygen) to prevent tearing during rolling. I will add this to our spec. *Pioneer did this for the 4 meter dipoles.* [ Part 2, Text/X-VCARD (charset: UTF-8 "Internet-standard ] [ Unicode") (Name: "wcrahen.vcf") 8 lines. ] [ Unable to print this part. ]