Research into Plastic Deformation of Double Reduced Sheets

Abstract

This contribution focuses on examining properties of thin steel sheets, which have been used to produce packages. Thin steel sheets for producing packages have been created with a different method (considering their thickness) than other thin steel sheets, such as sheets for the automobile industry. Steel sheets thinner than circa 0.18 mm are produced with a simple rolling and followed by annealing. Annealing can be completed through a batch process or a continuous process. Steel sheets with a thickness less than 0.13 mm are produced using a second reduction. Taking into account the considerably different strength and plastic properties of the sheets produced with simple rolling and the sheets produced with a second reduction, two types of materials are evaluated and analyzed in this contribution. Examined materials have been produced with different methods: The first material was continuously annealed after being rolled; the second was deformed using a second reduction without any subsequent annealing. Both used materials possess different final properties. The research focused on evaluation of the strength and plastic properties of the packaging sheets during various stress-strain states (uniaxial tensile test and biaxial tensile test—bulge test). The analysis also focused on the factors that led to a lack of inhomogeneity in the plastic deformation, mainly during the uniaxial tensile test causing the localization of the plastic deformation.

Keywords

• inhomogeneity of plastic deformation
• thin steel sheets
• uniaxial tensile test
• bulge test