Research on the Diffusion Behavior of Cu in Low-Carbon Steel under High Temperatures

Huirong Li,Tao Ma,Yueying He,Yungang Li

doi:10.3390/cryst12020207

Abstract

The effective diffusion of Cu in Fe is the key to forming a stable transition layer between copper and low-carbon steel, but it is seriously affected by several factors, especially temperature, and the diffusion of Cu can only be completed at high temperatures. In order to analyze the diffusion coefficient of Cu in low-carbon steel under high temperatures, and to obtain the best diffusion temperature range of Cu in steel, the electrodeposition method was used to prepare the diffusion couple of copper and low-carbon steel, which would be annealed under different temperatures for 6 h; meanwhile, the MD models were also used to analyze the diffusion behavior of Cu in Fe at different temperatures. The results show that the diffusion of Cu in low-carbon steel could be realized by high-temperature annealing, and as the temperature increases, the thickness of the Cu/low-carbon steel transition layer shows an increasing trend. When the annealing temperature is between 900 °C and 1000 °C, the thickness of the transition layer increases the fastest. The results of the MD models show that, when the temperature is in the phase transition zone, the main restrictive link for the diffusion of Cu in Fe is the phase transition process of Fe; additionally, when the temperature is higher, the main restrictive link for the diffusion of Cu in Fe is the activity of the atom.

Highlights

Due to its excellent comprehensive mechanical properties and relatively low production cost, low-carbon steel has become the most widely used structural functional material.when it is exposed to the air, Fe, the main component of steel, reacts with oxygen to form iron oxides, resulting in corrosion of the surface of the steel
The diffusion behavior of Cu in low-carbon steel, which has a great influence on the Section a~b: the heat preservation stage, the sample was placed in the constant microstructure of the surface of the steel
The diffusion of Cu in low-carbon steel can be realized by high-temperature annealing; as the temperature increases, the thickness of the Cu/low-carbon steel transition layer shows an increasing trend

Summary

Introduction

Due to its excellent comprehensive mechanical properties and relatively low production cost, low-carbon steel has become the most widely used structural functional material.when it is exposed to the air, Fe, the main component of steel, reacts with oxygen to form iron oxides, resulting in corrosion of the surface of the steel. The corrosion of the steel mainly originates from the grain boundaries and the defects of the steel microstructure. To avoid corrosion of steel, the corrosion of the grain boundaries and the defects should be prevented first. The reason is mainly that the Cu is the corrosion-resistant element, and it is easy to segregate at the grain boundaries and the defects of the steel, thereby effectively playing a role in preventing the corrosion of the grain boundaries and the defects [4,5,6]. The increase in Cu content in steel means that the Cu segregation would intensify and the crack defect rate of Cu-containing steel would increase significantly

Results

Discussion

Conclusion