PROCEDURE FOR PRODUCTION OF HIGH DURABLE STRIP FOR MAIN PIPES OUT OF LOW ALLOYED STEEL Russian patent published in 2011 - IPC C21D8/02 C22C38/04 

FIELD: metallurgy.

SUBSTANCE: work piece is preliminary subjected to re-crystallisation heating at temperature above Ar₃ at 20÷60°C, to conditioning at said temperature during 1-3.5 hours upon its complete heating and to cooling to temperature as high, as 100°C at rate as high, as 50°C/hour. Further, there are performed austenisation of uninterruptedly-cast work piece, rough rolling, breakdown bar sub-cooling in air prior to finish rolling, finish rolling, strip accelerated cooling to specified temperature and successive decelerated cooling strips in a pile. Strips are rolled out of low alloyed steel with contents of carbon as high, as 0.1% and manganese as high, as 1.9%. Also, re-crystallisation heating and regulated cooling are performed before there is created austenite grain of average dimension in an uninterruptedly-cast work piece as high, as 200 mcm at simultaneous reduced development of liquation strip or its elimination. Average dimension of actual grain of ferrite on the strip is 3-6 mcm.

EFFECT: upgraded quality of high durable uninterruptedly-cast strip.

2 cl, 1 ex