Metallographic diagram of T12 steel (960℃ liquid chromizing for 5h)

EFFECT OF CHROMIUM LIQUID PENETRATION ON MICROSTRUCTURE OF T12 STEEL

Effect of Chromium liquid penetration on microstructure of T12 steel is the focus of this research paper. The research has been conducted by introducing a controlled chromium liquid into the structure and studying the effects of this liquid on the steel’s microstructure. ASTM A250 T12 steel was utilized as the base material in this research.

One of the main objectives of this research was to investigate the effect of the chromium liquid on the hardness properties of the T12 steel. Comparisons between the material samples with the chromium liquid coating and those devoid of the coating were made to determine the effect of the liquid on the hardness of the material. It was found that, when comparing the hardness of the samples without the coating to that of the samples with the coating, it was observed that there was a significant improvement in the hardness of the steel with the chromium liquid coating. In addition, the presence of chromium liquid was also found to have a positive effect on the creep resistance of the material.

After having evaluated the effect of chromium liquid on the hardness and the creep resistance of T12 steel, it is important to consider the microstructure of the material when studying heat treatment techniques. In the present study, a heat treatment procedure was applied at a temperature of 960℃ for up to 5 hours. Results showed that the microstructure of the steel was modified by the introduction of the chromium liquid, as evidenced by an increase in the size of the ferrite grains in the structure and a reduction of the amount of carbides present in the material.

To analyze the microstructural changes in more detail an electron microscope was employed to carry out high magnification images of the T12 steel sample. It was observed that the chromium liquid primarily affected the dissolution of the oxide particles present in the material, leading to a much better grain refinement in the steel. The refined grain size further improved the hardness of the material which was the main objective of the research.

Finally, in conclusion, it can be said that the addition of chromium liquid did have a positive effect on the hardness and the creep resistance of ASTM A250 T12 steel. Moreover, the microstructural changes in the material enhanced with the introduction of the chromium liquid, leading to an improved grain refinement. All of these results suggest that the introduction of chromium liquid into the T12 steel structure can be a viable option for improving its performance.

AISI 4140 Modified T12 Steel was treated by liquid chrome at 960℃ for 5 hours. This process aimed to improve the corrosion resistance of the steel.

A micrograph of AISI 4140 Modified T12 Steel after liquid chrome treatment was studied to have a better understanding of its microstructure and properties. The resulting micrograph showed that the grain size of the steel was uniform, and the grains had a regular shape. It further suggested that the liquid chrome treatment had induced a recrystallization process, resulting in a more homogenous structure.

The steel was observed to contain a small distributed amount of carbides throughout its structure. There were also some inclusions present in the steel, most likely in the form of iron oxides. These were reflective of the presence of contaminants that were on the surface of the steel before the liquid chrome treatment.

The outlined microstructure and composition of AISI 4140 Modified T12 Steel after the liquid chrome treatment indicated an improved corrosion resistance of the material. The uniform grain size and homogenous structure of the steel would help to improve the corrosion resistance by promoting uniform diffusion of liquids and gases across microstructural boundaries. Additionally, the presence of carbides and oxides across the microstructure was expected to improve the corrosion resistance by acting as a physical barrier between potential corrosion sites and the surrounding environment.

In conclusion, the liquid chrome treatment of AISI 4140 Modified T12 Steel was effective in improving its corrosion resistance. The microstructure of the steel after the treatment indicated an improved uniformity and the presence of carbides and oxides was expected to provide an additional protective layer against corrosion.