rolled-in scale

Defect Name: iron oxide scale pressing < br / > definition and appearance: < br / > iron oxide scale is pressed into the surface of strip steel during hot rolling, or the iron oxide scale on the surface of strip steel is not completely cleaned during pickling process, or the marks left by iron oxide scale pressing are not completely eliminated during cold rolling. The appearance of this defect can be pitting, line mark or large-area indentation, It can appear anywhere on the surface of strip steel& nbsp;  & nbsp; Cause: < br / > ● pressed iron oxide scale defect exists on the surface of cold rolled substrate< Br / > ● the scale is not broken enough during pickling and tension straightening, and the pickling is not clean< Br / > ● the pickling process is unreasonable, the acid temperature and concentration are low or the pickling speed is too fast< Br / > hazards: < br / > ● defects that affect the surface quality and coating effect of steel strip and produce pits< Br / > prevention and elimination methods: < br / > ● improve the descaling effect of hot rolling< Br / > ● strengthen the inspection of cold rolled substrate< Br / > ● strengthen the pickling process control, and set the acid temperature, concentration and pickling speed in strict accordance with the regulations< Br / > inspection and judgment: < br / > ● visual inspection< Br / > ● steel strips for stamping, household appliance panels and other surfaces are not allowed to have the defect of pressing iron oxide scale. Generally, steel strips are allowed to have slight pressing iron oxide scale< br/>