invention cannot be attained the upper limit of the temperature at which the slab is heated is not specified but based on practical considerations 1 300 u00b0 c would be a preferable upper limit in order to ensure that aln will not precipitate during hot rolling the temperature at which the hot rolled steel is coiled must be specified to achieve this end as well as to ensure consistent production the lower limit of the coiling temperature is set at 400 u00b0 c the upper limit depends on the contents of al and total n and should satisfy the following formula equ3 where log is the common logarithm and al and n are both in wt the steel emerging from the last rolling stand is cooled on the runout table as it is taken up by the coiler for maintaining n and al in the rolled steel in better condition the cooling pattern is preferably such that quenching in the first half of the cooling zone is done more rapidly than in the second half other operations on the hot strip mill may be performed by normal procedures and the finishing operations after coiling may be also done by the conventional procedures liquid steels having the.