*Defect judgment:
There are obvious spot, block and strip defects on the surface of the steel plate. After annealing, it will appear obvious white or black. In serious cases, surface peeling, irregular defects and uneven concave-convex defects will appear. It is easy to judge the inclusion with peeling, but it is easy to be confused for the determination of slight surface stripe inclusion and surface scratch. Judgment this main difference is the Ge injury is more regular, uniform, width is very narrow; Strip inclusion is not too regular, uneven, wide width. Or through the surface grinding, scratch surface depth will not be deep, a grinding can be eliminated, and inclusion is deep, after the surface grinding, there will be depth extension.
* Cause analysis：
Inclusion is caused by non-metallic inclusions in continuous casting process, which begin to exist under the skin of billet, and are exposed to the surface after hot rolling and cold rolling. Due to the existence of oil and oxidation and other impurities on the surface of rolled hard plate, the inclusions are not obvious, and can be clearly revealed after annealing.
*Treatment methods:
1） Prepare samples, take photos and record them, and write quality feedback for the last process in one direction
2) Remove the found inclusion defects before the finished product annealing process is finished
3) After annealing, the found small defects shall be degraded by the repair and repair function
Post time: Jul-16-2021