Comparative experimental and numerical study on the mechanical properties, formability, and microstructure of two high strength steel sheets

Abstract

Experimental and numerical analysis of formability behavior for two types of steel sheets, namely E335D and DP600, was conducted. The former is a high strength low alloy (HSLA) steel, while the latter is an advanced high strength steel (AHSS). Initially, mechanical tests including uniaxial tensile test and the Erichsen cupping test were performed. Tensile test revealed that AHSS steel had higher yield and tensile strength, higher uniform elongation, as well as smaller non-uniform elongation. Then, forming limit diagrams (FLD) were determined via both experimental and numerical approach. Numerical modeling of the forming limit diagrams was carried out by means of the finite element analysis (FEA) ABAQUS/CAE software, using Hill’s 1948 yield criterion considering maximum thickness strain as the point of necking. The resulting forming limit diagrams were compared with the experimental results and showed a good agreement between the two, suggesting capability of the Hill’s 1948 yield criterion for predicting formability of the tested materials.