The rolls will exist some defects because of long term use, such as cracking, spalling. Sometimes the rolls will have incorrect dimension because of above defects. When meet these problems, the manufactures will use surfacing technology to restore the rolls.How to machining the surfacing rolls? The following is some tips:
1.Before restoration
(1)Clean the rolls surface, to ensure the cracks are cleaned;
(2)Ultrasonic Inspection,to check that if it has defects;
(3)Reduce the rolls heat: Lower the cooling rate between the metal and the heat affected zone in the process, lower the welding stress;
2.In the surfacing surface
We can choose the rolls surfacing methods depending on the rolls materials, specification and failure mode. Such as SMAW welding suit foe small qty and irregular rolls.
3.After restoration
The surfacing rolls need heat treatment, and remove the welding stress, improve the rolls performance, and Prevent the generation of delayed cracks.Then machining the rolls and restore the dimension and surface quality. Normally it has 2 methods to restore the surface dimension and the surface quality: Grinding and Turning. With the development of the society, Halnn researched solid cbn insert BN-S20, which can realize turning surfacing rolls, improve the process efficiency and reduce the production costs.
Halnn, as one of the manufacturers which offer solutions and the environmental advocates, continued to innovate, enhance core competitiveness of products, clients gradually expanded to various mechanical industries.
Halnn always offer customers high-quality, high-performance tool products and can quickly meet the increasingly diverse needs. Halnn committed to making the world no longer have difficult to machine materials.
For large-scale rolls,we usually use turning instead of grinding process, for example Halnn superhard BN-S20 grade CBN inserts machining the restored rolls ,the precision can reach Ra0.4. But if the rolls required precision above Ra0.4,we recommend that grinding after turning .
If you have any problems,please feel free to contact with us info@halnntools.com, skype:info@halnntools.com.