DEVELOPMENTS OF -45℃ GRADE 09DR STEEL AND PRECISION SEAMLESS STEEL TUBE FOR CASING CRYSTALLIZING MACHINE

The paper introduces the development of V-Ti trace alloyed -45℃ Grade 09DR Steel and the rolling process of the special precision seamless steel tube for casing crystallizing machine by applying the technology of heavy reduction and final temperature control. The tests concerned indicate that the above mentioned special tube is of such characteristics as the brittleness transformation temperature of -65——75℃, Charpy impact value five to eight times as high as the allowable value specified in JISG3460-84 and both the comprehensive performances and dimensional tolerance better than those of the similar products manufactured abroad.