Politecnico di Torino | Servizi per la didattica

KEYWORD

New coatings for forming rolls

azienda Thesis in external company

Reference persons PAOLO MATTEIS, RAFFAELLA SESANA

External reference persons Guido Ferrarese, MA Srl.

Description In the automotive sector, many high-strength steel components are fabricated using the roll forming process. This process involves the continuous bending of a strip of sheet metal into a desired cross section. The strip passes through stes of rolls mounted on consecutive stands, each of which performs only an incremental part of the deformation, until the desired profile is obtained. Rollers are normally made from tool steel and coated to reduce friction and improve wear resistance.
In recent years, this process has been applied to steels with increasingly higher strengths, up to martensitic steels with a nominal strength of 1800 MPa. The increase in the mechanical strength of the sheet causes an increase in the contact forces and therefore also makes the phenomena of friction between the rolls and the sheet and wear of the rolls themselves more critical.
Therefore, in the course of the thesis, possible alternative coatings will be evaluated to improve the life of the rolls and reduce the frequency of the maintenance stops.
In this context, the thesis student will carry out a theoretical examination of the problem and will contribute to the experimental evaluation of different types of coatings. These coatings will be made (by third party companies) on small simulacra, which will be manufactured with the material of the rolls. During the thesis work, the coated simulacra will be subjected both to functional tests, performed in the company, and to laboratory characterizations, mainly performed in the polytechnic laboratories; the latter may include both metallographic and hardness tests and tribological tests of friction and wear.
The work in the company will mainly take place at the headquarters of the CLN group in Rivoli (TO). At the request of the student, the thesis can be combined with an internship in the same company. The thesis proposal is open to both national and international students, and the work can be carried out, at the student's choice, in Italian or English.