twin roll strip caster the cast and solidified sheet is discharged into air at a temperature of about 1415 u00b0 c and cooled in an insulated enclosure at a rate of about 15 u00b0 c second to a surface temperature of about 1230 u00b0 c at which point the cast strip is subjected to rapid secondary cooling using the water spray method of the present invention rapid secondary cooling is accomplished by applying spray water to both surfaces of the sheet table iv composition of grain oriented electrical steel example c mn s si cr ni cu al n a 0 029 0 064 0 023 3 28 0 25 0 080 0 080 0 0060 0 0058 b 0 033 0 051 0 026 2 94 0 25 0 080 0 082 0 0005 0 0065 steel a of table iv is provided with rapid secondary cooling whereby a water spray density 1000 l min m 2 on each surface of the sheet is applied for a time of about 5 seconds to lower the strip surface temperature from about 1205 u00b0 c to about 680 u00b0 c steel b is provided with rapid secondary cooling using a water spray density of about 175 l min m 2 for about 0 9 second followed by a 400 l min m 2 application for about 4 5 seconds on each surface of the steel sheet to lower the strip surface temperature from about 1230 u00b0 c to about 840 u00b0 c the cast and cooled strip is air cooled to 650 u00b0 c coiled and cooled thereafter to room temperature extensive cracking occurred with.