abstract
- Copyright © 2017 SAE International.The rapid growth of the emerging markets has pushed the automotive original equipment manufacturers to relocalize production to reduce manufacturing and logistic costs. To ensure an efficient and flexible supply chain, local suppliers are appointed. However, the characteristics of materials available in each region may have minor differences, and when geometry and process design recommendations that were developed for certain materials are implemented for materials under a different regional standard, different results are obtained. Such is the case of the clutch disc spacer bolt, in which its compression during riveting has a direct effect in the noise and vibration isolation of the vehicle. It has been reported that spacer bolts produced with materials considered to be equivalent in Europe and North America (DIN C10C and SAE-AISI 1010 steels) behave different during riveting, even though they have very similar chemical compositions and are delivered with a similar UTS and ductility. The aim of this paper is to compare the compression behavior of both materials during riveting, and to explain the factors affecting the material response during compression that lead to differences in the final geometry. Finite element simulations are used for the analysis and validated experimentally by a controlled prototype production. Results indicated that 1010 steel compresses in average 0.3 mm more than C10C steel, caused by the yield stress difference. Experimental results were within the simulation results range. Microstructural analysis and microhardness measurements are reported in order to explain the deformation mechanisms. Finally, a change in the spacer bolt barrel dimension prior riveting is proposed based on finite element simulations to overcome their differences and produce a rivet under specification.