The S and P maximum levels, for several grades in this specification, were not representative of the materials that are actually produced today. At the maximum levels in the -11 edition of the specification, 0.040 P and 0.045 S, for WC6, WC9, C12, and CA15; and an S content of C12a of 0.030, there are detrimental effects on toughness and corrosion resistance. The Steel Founders Society of America (SFSA) collected a large amount of data from sand and investment casting producers and subjected it to rigorous statistical analysis. In view of that data analysis, the maximum permitted levels for P and S were reduced by approval of WK35710 to 0.035 for P and 0.035 for S. These are the levels in the current A217/A217M-12 edition. Committee A01.18 established a TG to review the data and its analysis, and to make recommendations for levels that do represent current production. This action, to further reduce the maximum levels for P and for S, for Grades WC6, WC9, C5, C12, and CA15, to levels supported by the SFSA data analysis, was on SCLB A01.18 (04-13) and received several negatives. At the November 12, 2013, meeting of A01.18, the negative votes were deemed persuasive. The subcommittee suggested that the reduced S and P levels should be placed in a Supplementary Requirement. The SR can thend be invoked by purchasers interested in lower levels of S and P.
Keywordsalloy steel; high temperature; martensitic stainless steel; pressure containing; steel castings ;
Ballot Item Approved as A217/A217M-2014 and Pending Publication