Performance evaluation of HSLA steel subjected to underwater explosion

Performance evaluation of High Strength Low Alloy (HSLA) steel subjected to underwater explosion is of interest to materials engineers because of its structural applications in ships and submarines. Circular and rectangular plates were investigated for their explosive response because they represent panels of a ships plating. Underwater explosion bulge tests were carried out with increasing shock intensity on 4 mm thick circular plates of 290 mm diameter and rectangular plates of 300×250 mm to study the plastic deformation and the onset of fracture. Empirical models were developed for the prediction of depth of bulge of the plates. A fresh set of tests with various explosive charge quantities and stand offs were carried out which showed good agreement with the models. Failed edges of the plate showed slant fracture suggesting ductile mode of failure. Scanning Electron Microscopic (SEM) fractographic examination showed dimple features suggesting micro void coalescence.