Application of the High Strength Steel HARDOX 450 for Manufacturing of Assemblies in the Military Industry

Abstract

The problems related to welding of the high strength steel, aimed for manufacturing of welded structures operating in the prominent wear conditions, is considered in this paper. The paper presents an analysis of possibilities and prescribing the technology for welding the high strength steel HARDOX 450. The methodology for estimate the weldability of this steel was established in the theoretical part of the paper, as well as calculations of the welding parameters, while the hardness was investigated in details and the macro and micro structures of the individual welded joint zones were estimated in the experimental part. Obtained experimental results could be usefully applied for selecting and establishing the optimal welding technology for structures made of this steel. The technology thus established and the GMAW welding regime can enable successful execution of the welded joints and reduce the possibility for appearance of flaws and cracks to a minimum.

Influence of the Welding Joint Type on Safety Properties of the Armor Steel Armox 500t

“…Taking into account these requirements, it was inevitable to develop the special group of the high-strength steels, known as the armor steels that are being improved (Arsić et al, 2014). The Swedish company SSAB Oxelösund (www.ssab.com)has the high-strength steels in its production program, where the especially interesting is a group of armor steels, known under the commercial brand ARMOX, which are produced according to the strictly defined manufacturing procedures (Lazić et al, 2017). Their excellent properties are resulting from the manufacturing process.…”

“…Their excellent properties are resulting from the manufacturing process. They possess a very low content of carbon what positively affects their weldability, while the strength is being achieved by application of the thermo-mechanical processing (TMP) (Arsić et al, 2014, Lazić et al, 2017. However, despite their exceptional properties, when the armor is being welded, the worsening of those properties occurs, locally, due to the entered heat.…”

Effect of welding parameters on the mechanical and metallurgical properties of armor steel weldment

“…The issue with the armor steel is that it reaches very high hardness (around 500 HV) and tensile strength (around 1650 MPa) using complicated processing called thermomechanical controlled processing (TMCP) at high temperatures, including quenched and tempering. This process resulted in the fine grains martensitic structure with ultrahigh strength properties, considering that this makes the steel sensitive to any thermal processing including cutting and welding processes [7,9].…”