Determination of possible causes of miss roll (cobbles) in steel rolling industries in Nigeria

Three steel rolling mills in Nigeria, tagged A, B and C were visited in order to determine the potential causes of miss roll (cobbles) in steel rolling industries in Nigeria. Test rolling was carried out in each mill. Prior to the test rolling, the mill train was thoroughly inspected and all the necessary maintenance on the mill train was carried out. When all the conditions were confirmed satisfactory, test rolling was then carried out and the rolling process was observed along the mill train. Each time cobble occurs; production was stopped momentarily until the cobble was removed.