Method for cooling rolled steels

A method of cooling rolled steel comprising the steps of:

• hot-rolling steel to the desired diameter;
• subsequently passing the steel along a path and quenching the hot-rolled steel by spraying cooling waters thereon to cool the surface portion of the steel to a temperature within a given range below the bainite transformation temperature, the temperature range being defined as
• 145.multidot.t/r.sup.2 +130.ltoreq.T.ltoreq.152.multidot.t/r.sup.2 +240
• where
• T=surface temperature of the rolled steel at a temperature measuring point along said path 1 m to 2 m away from the point along said path where quenching ends (.degree.)
• t=time required for the rolled steel to travel along said path from the quenching ending point to the temperature measuring point (hr)
• r=radius of the rolled steel (m);
• and
• subsequently continuing to pass the quenched steel along said path in ambient atmosphere for causing the temperature of the surface portion of the rolled steel which has been cooled by the quenching to reelevate to a reelevated temperature as a result of the conduction of the heat retained in the inner part of the rolled steel to the surface portion of the steel for tempering the steel.