Design and manufacture of roll forming line for bimetallic U profile production

Bimetallic sheets are the production of two metals with different properties by various methods such as adhesive bonding, pressure welding, cold and hot rolling, blast welding and roll bonding. Bimetallic sheets are used to provide features that cannot be achieved with a single metal. With the produced double layer bimetallic sheets, different properties such as high mechanical properties, corrosion resistance, lightness, high wear resistance, electrical conductivity, thermal characteristic and shock absorbency are obtained. The roll forming process is the method of obtaining the desired profile by bending the sheet material while passing through the forming stations positioned respectively. Roll forming is an advanced production system that enables easy manufacturing of profile parts of different cross-sections. In this study, Al 1050 (H14) aluminum alloy and 304 quality stainless steel plates were stacked on top of each other after chemical and mechanical cleaning of the surfaces, annealed in the heater oven at 430º for 60 minutes and bonded to each other by roll bonding method in three cycles. The double-layered sheets produced were shaped with a roll forming line specially manufactured for the study and a 500 mm long U profile was produced. Afterwards, by changing the machine setting parameters, how the longitudinal bowing and edge waviness defects that occur during the U profile shaping change depending on the bending angle increase, the distance between stations and the line speed parameters were investigated experimentally and numerically. The results show that for a 500 mm long U profile, by reducing the number of stations from 8 to 4, the longitudinal bowing is 8.1 mm in the experimental study and 7.6 mm in the simulation study. In the 4-station model, the edge waviness was observed to be prominent both in the experimental study and in the simulation study. For a 500 mm long U profile, it was observed that the longitudinal bowing was 0.7 mm in the experimental study and 0.9 mm in the simulation study by reducing the distance between stations to 156 mm. No quality difference was observed in the tests performed at the distance between 250 mm and 400 mm stations. According to the profile section, while these defects appear below a certain limit distance, it has been observed that there is no change even if the distance is increased above a certain limit. It has been observed that there is no difference in the profile sections produced by increasing the line speed from 51.5 mm/s to 193 mm/s for the 500 mm long U profile. As a result, it has been seen that the increase in bending angle increment is a more important criterion than the change in the distance between stations and the change in line speed in shaping the double-layered Al 1050-304 stainless steel plate with the roll forming method.