Study of the effect of the process parameters on the forming limit in shear spinning processes

Abstract

Shear spinning is an incremental metal forming technique with several advantages when compared with traditional sheet metal forming technologies, including low force requirements, simpler tools, and the capability to produce complex geometries. In this process, a large deformation can be applied due to the localized compressive and shear stresses, which enhance the ductility more than conventional forming processes. Therefore, the final part improves considerably its mechanical properties due to the associated work hardening. Nevertheless, the shear spinning technology involves a complex material flow that is highly dependent on the process parameters. In consequence, it is essential to study the effect of the different parameters on the formability of any material in the shear spinning process, but more importantly, to develop a method to predict the forming limit in terms of such parameters to get most of the process. In this work, a novel approach to study the formability in terms of the radial force was introduced. In this sense, shear spinning experiments on mild steel (DC-04) and martensitic stainless steel (AISI 420) were carried out, to derive forming limit maps as a function of the mandrel wall angle (30–7°), the spindle speed (400–1000 rpm), the feed rate (0.01–1.2 mm/rev), and the roller attack angle (0–30°). It was found that the maximum thickness reduction that the materials can withstand was 84% and 80% for the DC-04 and AISI 420, respectively. The results showed that the spindle speed presents a minor effect while the feed rate and radial force greatly affect the formability; therefore, a parametric equation was proposed to describe the boundary between the safe and failure zones in terms of the maximum thickness reduction. Regarding the mechanical properties, the maximum hardness increment regarding the as-received materials was 73% and 42% for the DC-04 and AISI 420, respectively.

The authors acknowledge the funding support from the Spanish “Agencia Estatal de Investigacion (AEI)” through project CONDISIM RTC-2017-6169-5. The collaboration of Industrias Puigjaner S.A (DENN) is also gratefully recognized. S. Elizalde also acknowledges AGAUR (Generalitat de Catalunya) for his Ph.D. grant 2019FI-B00172. P. Coyoy acknowledges his master’s degree grant provided by the European Commission through the AMASE program. Valuable technical support provided by K. Albo, and I. Lopez is also acknowledged.

7 - Energia Assequible i No Contaminant

9 - Indústria, Innovació i Infraestructura

12 - Producció i Consum Responsables

Postprint (published version)