METHOD FOR PRODUCTION OF HOT ROLLED PIPE STEEL ROLLS Russian patent published in 2009 - IPC B21B1/26 

FIELD: technological processes.

SUBSTANCE: slab for hot rolling is heated, then it is hot-rolled with the first vertical single draft in the range of 20-90 mm, further horizontal drafts in cages of rough group and further hot rolling of strip in finishing continuous group of broad-strip mill with cooling of its surface with water in intercage gaps and on collecting roller table with further reeling of strip in roll. Locating of cracks in near-edge sections of strip is provided by the fact that in the first cages of rough group, differential drafting of slab is done depending on final thickness of strip. In the first horizontal pass, value of relative drafting for strips with final thickness of more than 8 mm and 12 mm inclusive does not exceed 18.5%, in the second horizontal pass relative drafting does not exceed 21%, and for strips with final thickness of more than 12 mm and up to 16 mm inclusive, the first horizontal drafting does not exceed 16.5%, the second horizontal drafting does not exceed 18%.

EFFECT: higher yield of rolled metal in production of broad hot rolled strips.

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