Electrochemical and hot corrosion behaviour of steel reinforced with AlSiBeTiV high entropy alloy using friction stir processing

Ragunath Sundaram; Radhika Nachimuthu; Aravind Krishna Sivanandam; Jeyaprakash Natarajan

doi:10.1080/14686996.2024.2320083

Electrochemical and hot corrosion behaviour of steel reinforced with AlSiBeTiV high entropy alloy using friction stir processing

Sci Technol Adv Mater. 2024 Feb 19;25(1):2320083. doi: 10.1080/14686996.2024.2320083. eCollection 2024.

Authors

Ragunath Sundaram¹, Radhika Nachimuthu¹, Aravind Krishna Sivanandam¹, Jeyaprakash Natarajan²

Affiliations

¹ Department of Mechanical Engineering, Amrita School of Engineering, Amrita Vishwa Vidyapeetham, Coimbatore, India.
² School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou, China.

Abstract

A lightweight AlSiBeTiV high entropy alloy (HEA) powder is synthesized by the ball milling process and is reinforced on SS410 through friction stir processing (FSP). Subsequently, the annealing process is conducted on the processed samples at 450, 600, and 750°C for 120 mins. The grains are refined at 600°C by 23.3% than the processed HEA sample. A higher microhardness of 672 HV is attained on the processed HEA sample annealed at 600°C due to the synergistic effect of FSP and annealing through refined grains. The electrochemical corrosion under a 3.5 wt.% NaCl environment, and the hot corrosion under the salt mixture environments of 75% Na₂SO₄ +25% NaCl, and 60% Na₂SO₄ +20% NaCl + 20% V₂O₅ at 800°C for 50 h are investigated on the processed samples. The microstructure, induced corrosion products, and elemental distribution of the corroded surface of the annealed processed HEA sample are evaluated by morphological analysis. The induced oxidation effect enhances the Cr₂O₃ and TiO₂ films on the corroded surfaces leading to higher corrosion resistance. A high corrosion resistance appears on the annealed processed HEA sample through the formation of a stable passive layer, hindering the pitting corrosion mechanism, grain refinement, and homogeneous distribution.

Keywords: High entropy alloy; annealing; electrochemical and hot corrosion; friction stir process; microhardness.

Plain language summary

So far, the majority of work focuses on Al and composites. However, the current work made a surface modification on SS410 steel by reinforcing lightweight HEA particles through friction stir processing followed by the annealing process. The lightweight AlSiBeTiV HEA particles are reinforced in SS410 through FSP and subsequently annealing process is performed for enhancing the refined grain structure.Corrosion behaviours of processed samples at room and high temperature and the effect of annealing on corrosion behaviours of HEA reinforced steel are a novel area in materials science.