Wire surface parallel to the direction of the extended rolling bar raised called lugs, was continuous or intermittent distribution. On one side of the wire called unilateral lugs; on both sides of the wire called bilateral lugs; wire up and down the two semicircular staggered called wrong side lugs. Mainly caused by the rolling groove overfilled. In the high-speed wire rod mill working, the final product of the head and tail ends is difficult to avoid the generation of lugs.
With lugs of the mechanical properties of the wire is not uniform, when used for deep processing, resulting in uneven deformation, reducing the drawing performance, and to wear and tear the mould.
The reasons generated lugs as below
1 Billet temperature is low, resulting the rolled parts to turn wide and small extension;
2.Pass design is unreasonable;
3.Guide design isn’t reasonable or poor processing or guide installation is not correct;
4.The installation isn’t good mill results in shaft runout;
5.Improper adjustment of material type, large incoming material or heap of steel in the front rack of the finished product, resulting in overfilling of the finished hole;
6.Billet defects, such as shrinkage, segregation, delamination and other foreign inclusions affect the normal deformation of the rolled parts, but also the cause of the formation of lugs;
Prevention methods
1. Ensure the quality of billet heating, avoid roll cooling water poured directly onto the surface of the rolled parts;
2. That shall have right pass design;
3. The design of the guide should be reasonable, and there are good guide processing and installation of the guide to meet the process requirements;
4. Rolls have good processing and assembly quality;
5.Proper allocate the amount of reduction in each pass.
