Cold rolled steel strip packing pressure into the iron oxide appearance defect inspection

( 1) Defect characteristics: hot rolled iron oxide is pressed into the steel plate surface, covered, strip or mottled black patches. Its distribution area size, pressure into the depth is not consistent. ( 2) Reason: hot rolled steel pressure oxidation of iron, residue on the steel surface after rolling. ( 3) Prevention and elimination methods: used for LiaoChang take measures to prevent the oxidation of the hot-rolled steel strip packing surface pressure into the tin. ( 4) Check: check with the naked eye. Ordinary plate, the high quality gb regulation is not allowed to have pressure into the iron oxide. Common plate or rules allow a slight pressure into the iron oxide.