Cold rolling rolls are prone to problems and treatment

Cold rolling process rolls on the strip steel production, plate quality, tons of steel cost consumption of the three major indicators have a great impact. Defects in the use of cold rolling rolls will cause batch product quality degradation or even scrap, resulting in a reduction in the rate of finished products, and may lead to damage to related equipment. Therefore, the domestic cold rolling manufacturers are very focused on the use of roll research, is committed to effectively reduce the consumption of cold rolling rolls. Article for a steel stainless steel cold rolling site production process rolls common defects, briefly analyze the common causes of roll defects and, put forward measures to deal with.
A steel cold rolling mill in the early stage of mill production, roll surface defects to the production of great distress, to a large extent, affecting product quality and production rhythm. Roll surface defects mainly include vibration lines, roll marks, knife flower, cracks and spalling, these defects will have an impact on the product surface. Explore the formation of these defects and solutions, the production of the site has great significance.


1 vibration pattern
In the strip rolling process, the strip surface will often appear a kind of dark and light, and the direction of the strip movement perpendicular to the strip, the strip defects called strip vibration pattern. Practice has proved that most of the causes of this strip vibration pattern come from the roll, that is, the roll vibration pattern copied to the strip surface.
1.1 Roll vibration causes
Roll vibration causes and manifestations are mainly the following: vibration of the grinding wheel spindle vibration caused by the roll vibration, vibration pattern in the form of a spiral distribution on the surface of the roll; grinding wheel shape or grinding wheel degranulation caused by poor roll vibration, vibration pattern in the form of a spiral distribution on the surface of the roll, usually through the speed of the roll and the speed of the grinding wheel to measure the vibration pattern of the spacing and then with the actual control, can be accurately judged to be the vibration pattern of the grinding wheel. The vibration of the grinding wheel can be accurately determined; the vibration of the rolls caused by poor contact with the roller bracket (tile), the vibration pattern is distributed on the roll surface in the form of parallel to the roll bus; the vibration of the rolls caused by the poor shape of the top of the tailstock, the vibration pattern is distributed parallel to the roll bus; the vibration of the rolls caused by the poor rotation of the headstock, the distribution of vibration patterns parallel to the roll bus; resonance caused by vibration between the vibration of the grinding wheel headstock and the vibration of the head box of the bed; the vibration of the vibration of the grinding wheel headstock and bed box of the vibration of the vibration of the vibration of the vibration caused by the vibration of the vibration of the wheel headstock and bed box. The vibration of the grinding wheel headstock and the vibration of the bed head box resonance caused by the roll vibration pattern, parallel to the form of the bus bar distribution on the surface of the roll.
1.2 Elimination method of roll vibration pattern
Elimination of roll vibration pattern, the first is to eliminate the abnormal vibration source, and then according to the vibration pattern of the obvious degree of choice of grinding method. Obvious vibration pattern should be eliminated from rough grinding, and the inconspicuous vibration pattern can be eliminated from semi-rough grinding.
2 Roll marks
①The manifestation and cause of roll mark. Roll roll mark is mainly manifested as roll surface pinholes, dents, indentations and holes. Irregularly distributed dents in the roll surface, generally round, surface condition or roll texture is usually retained in the dent, generally by some of the debris (foreign objects) into the bite area or rolls contact each other between the friction caused by friction. Preventive measures are: identify the source of debris and foreign objects, clean racks, improve process lubrication and cooling conditions, improve the surface quality of pickled coils and shear edge quality, increase the surface hardness of the work rolls and the depth of hardening, and rationalize the configuration of the work rolls and the intermediate rolls between the hardness difference.
② method of eliminating roll marks on rolls. According to the different degrees of roll marks by grinding or turning to remove the roll roll marks.

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