Debasis Impact strength is related to microstructue obtained and depends on the effect of thermo mechanical treatement for a given alloy. Particular microstructure gives benefit with lower finishing temperature. We cannot generalize on this. One cannot generalize based on one alloy composition and thermo mechanical treatment. Compositon of alloying elements : viz., C, Mn, Si, Ni, Cr, N, Mo individually and as alloying additions do play a part also and their behavior both at hot rolled conditions (either lower temperature or higher temperature of hot rolling) and in lower temperature transitions determine the impact properties. Foryour specific question on A 333 Gr 3,6, & 7 i had given answer. This will not be applicable for some other grade in A 213 or A 312 grades. Trust this answers your question C.V.Srinivasan Nish Engineers Pvt Ltd India Sept 22 E-mail:nishi@vsnl.com >Question to Mr. Srinivasan for one of his para : >QUOTE >Commercial steels are sold in "hot rolled" condition and the >rolling treatments have a considerable effect on impact >properties. Rolling to a lower finishing temperature >(controlled rolling - for ex: for grade 7) lowers the >impact-transition temperature. >UNQUOTE > >Q. As you have mentioned that Rolling to a lower finishing >temp. will lower the impact transition temp. i.e. it >indicates that the DBTT gets lowered which seems to be a >healthy phenomenon . Please comment. > >