Crystalline Phase Change Due to High-Speed Impact on Steel

Abstract

Standard alloy steels have many industrial applications because they are easily machined and welded. The alloy contains less than 0.3% carbon by weight and is considered a low-carbon alloy. Because of this low carbon content, the alloy is helpful as a general-purpose steel. It is extreme, tough, ductile, weldable, and malleable. It is used to build bridges, buildings, cars, heavy equipment, and the construction industry. A36 steel contains small elements, including manganese, sulfur, phosphorous, and silicon. so, these elements give the alloy steel the desired mechanical and chemical properties. The steel alloy A36 gets the number 36 on its name due to its yield strength. Steel has a minimum strength of 36,000 pounds per square inch. However, the effect of impact at high velocity on the crystalline structure and phase material is unspecified and the aim of this study.

The physical properties and molecular structure of steel from the effect of high velocity on grain structure and unknown properties are being studied in this research. The primary measure of the impact changes in the interconnected mineral crystal structure at various locations around the impact crater. The effect of super-projectile velocity on the crystalline grain structure near the target effect in almost all formations. This strength shows high some sites at all post-impact stages. This study also found that the crystal structure of BCC remained the dominant phase after impact. This result is realistic with all test samples and all levels of shock loading.

A36 steel has been studied and is predominantly a single- phase body-focused cubic (BCC) material. Impact speeds ranged between 3.54 and 6.70 km/s. Target subjects before and after impact were reviewed to determine if ductility in the material. The physical properties and molecular structure of A36 steel are also known.

Portions were cut from approximately 90 x 90 square microns of test samples, in line with standards required for surface finish. These surfaces were examined and analyzed after impact. The surface portions were selected from a range of areas, including areas directly below the impact crater, to sites that were not physically affected by the impact. Three different effect speeds were applied, and the prepared samples were examined. An EBSD (Electron Backscatter Deflection) imaging microscope is used to examine the crystal structure of the test specimen after impact.
Most minerals crystallize into one of three predominant structures: body-centered cubic (BCC), hexagonal closely packed cubic (HCP), or face- centered cubic (FCC). Since these crystal structures are the most predicted lattice configurations, postimpact samples are examined for changes in molecular structure assignment. The results were then tabulated according to the relative impact pit in the region. Previous research shows that post-impact inspection of HCP phase change, in iron specifically, can be entirely and rapidly reversed during impact.

However, in this study, traces of HCP were found at impact conditions led to a change in the A36 phase. The methods of electron microscopy, surveying electron back diffraction and X-ray of distortions, lattice defects, twinning, and phase shift were investigated. A limited number of targets were affected. 304L and HY100 were also examined. These alloy steels contain a BCC crystal phase and face-centered (FCC) hexagonal closed beam (HCP) structures. The grain size is close as well. The impact is compressed close to the impact site. Also, the twinning was located closer to the impact zone and gradually dissipated away from the impact zone. In contrast, the increase of the effect’s momentum increased the percentage of HCP.