Alloying Effects of BCC-Fe Based Low-Alloy Steel on Mechanical and Thermal Expansion Properties for a Plant Engineering: Ab Initio Calculation

초록

High-strength low-alloy steel is one of the widely used materials in onshore and offshore plant engineering. We investigated the alloying effect of solute atoms in alpha-Fe based alloy using ab initio calculations. Empirical equations were used to establish the effect of alloying on the Vicker's hardness, screw energy coefficient, and edge dislocation energy coefficient of the steel. Screw and edge energy coefficients were improved by the addition of V and Cr solute atoms. In addition, the addition of trace quantities of V, Cr, and Mn enhanced abrasion resistance. Solute atoms and contents with excellent mechanical pro-perties were selected and their thermal conductivity and thermal expansion behavior were investigated. The addition of Cr atom is expected to form alloys with low thermal conductivity and thermal expansion coefficient. This study provides a better under-standing of the state-of-the-art research in low-alloy steel and can be used to guide researchers to explore and develop alpha-Fe based alloys with improved properties, that can be fabricated in smart and cost-effective manners.

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