Forming Limit Diagrams of Perforated St12 Steel Sheets

One of the unique characteristics of sheet metals is their formability, which is determined by the forming limit diagrams. These diagrams specify the maximum deformation limit before part’s failure. For several applications of metal sheets, they have to be in the perforated format. Existence of holes in the perforated sheets may adversely deteriorate the forming limit of metal sheets. In this study, the effect of perforated sheets’ hole size and hole layout on their formability are investigated. Several specimens of St12 steel with 0.6 mm thickness, different widths, two various hole sizes of 2 and 4 mm, and two layouts of triangular and square were prepared. The specimens were tested using Nakajima test (stretch with a hemispherical punch) to generate the forming limit diagrams. It was observed that both the diameter and layout of the punched holes have a significant effect on the formability of the perforated sheets. The perforated sheets with triangular hole layout showed higher forming limits due to their larger ligament ratios.

Forming Limit Diagrams of Perforated St12 Steel Sheets

One of the unique characteristics of sheet metals is their formability, which is determined by the forming limit diagrams. These diagrams specify the maximum deformation limit before part’s failure. For several applications of metal sheets, they have to be in the perforated format. Existence of holes in the perforated sheets may adversely deteriorate the forming limit of metal sheets. In this study, the effect of perforated sheets’ hole size and hole layout on their formability are investigated. Several specimens of St12 steel with 0.6 mm thickness, different widths, two various hole sizes of 2 and 4 mm, and two layouts of triangular and square were prepared. The specimens were tested using Nakajima test (stretch with a hemispherical punch) to generate the forming limit diagrams. It was observed that both the diameter and layout of the punched holes have a significant effect on the formability of the perforated sheets. The perforated sheets with triangular hole layout showed higher forming limits due to their larger ligament ratios.

ADVANTAGES OF SCREENING IMBIBITION JUICES

Traditionally, all imbibition juices were screened through perforated sheets and cush cush was conveyed by scraper conveyor cum elevator ahead of mill # 2 in the tandem. With the introduction of DSM screens for the screening of mixed juice, the screening of imbibition juices was also discontinued and these juices were pumped directly along with cush cush through chockless pumps. At Shahtaj, we started screening of imbibition juices which proved to be a great success. In this case study, the advantages / benefits of new adopted system shall be discussed.

A Probabilistic Model of Optimising Perforated High-Strength Steel Sheet Assemblies for Impact-Resistant Armour Systems

This paper presents a concept for optimising an assembly of perforated metal sheets with a probabilistic theory, and the results of testing perforated bainite steel sheets with a nanocrystalline structure. The work presented herein was completed with an assumption of applying the perforated sheets in the design of anti-armour-piercing and anti-HEAT armour systems. The theoretical analysis and experimental research were performed for a 7.62x54 mm R API B-32 projectile and a PG-7 rocket-propelled grenade.