The Effect Of Rol-las On Micro Structure And Steel Hardness 15% Cr-25% Ni Nuclear Reactor Structure Material

Feb 27, 2025 by ADMIN 109 views

The Effect of Rolly Process on Micro Structure and Steel Hardness of 15% CR-25% NI as Material for Nuclear Reactor Structures

Introduction

The development of nuclear reactors requires the use of high-quality materials that can withstand extreme conditions. One such material is 15% CR-25% NI steel, a non-standard steel produced independently for use in nuclear reactor structures. The production process of this steel involves several critical stages, including machinery, rolling, and welding. The roller process is a crucial step in examining the material's behavior after undergoing thermo-mechanical treatment and welding, and its impact on changes in micro structure and steel hardness. In this study, we aim to investigate the effect of the roll process on the characteristics of steel material in the context of its application in nuclear reactors.

Materials and Methods

The 15% CR-25% NI steel used in this study was produced independently and used as a structural material in nuclear reactors. The roller process was carried out using a Tungsten Arc Welding (GTAW) gas method with a filler. The characterization of the material was done using various techniques, including optical microscopes, Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS), Microhardness Tester, and X-ray diffractometer (XRD).

Results

The results of the study showed that the micro structure in the base metal area (base metal) had an unorthodox characteristic, with the presence of carbide inclusion. In the Heat-Affected Zone (HAZ) region, observations showed that the grain's reporting, where the grain size was larger than the thermo-mechanically affected zone (TMAZ) area, which had a more uniform micro structure and smaller grains. Meanwhile, in the Weldcore area, a micro structure was found in the form of columnar dendrites that showed the complexity of the welding process.

In terms of hardness, the results of the test showed that the value of steel hardness after the roller process had decreased. The value of hardness in the base metal area was recorded at 143.58 HVN, while in the TMAZ, HAZ, and Weldcore areas, respectively, 107.44 HVN, 98.25 HVN, and 125.26 HVN. This decrease showed that thermomechanical treatment of the roll process and welding affected the structural strength of steel.

Analysis of XRD Test Results

The analysis of the XRD test results showed that the 15% CR-25% steel was the result of the roll process only containing one single phase, namely the phase-ƴ. The shift and widening of the observed diffraction pattern were the result of the welding process, which can affect the normalization of tensile stresses from the previous process.

Discussion

The importance of understanding the effect of rollers on this type of steel not only lies in aspects of hardness and micro structure, but also on how this material can behave under the operational conditions of extreme nuclear reactors. Thus, this kind of research is very crucial to increase the resistance and safety of nuclear reactor structure material.

Through an in-depth study of the effect of this roller, it is hoped that new techniques can be found that are more efficient in welding and material treatment, so as to maximize the performance of nuclear reactor structural materials that continue to develop. This will certainly have a positive impact on innovation in the field of nuclear technology in the future.

Conclusion

In conclusion, the study has shown that the roll process has a significant impact on the micro structure and steel hardness of 15% CR-25% NI steel. The results of the study have provided valuable insights into the behavior of this material under thermo-mechanical treatment and welding, and its potential application in nuclear reactors. The findings of this study have significant implications for the development of new techniques in welding and material treatment, which can lead to the creation of more efficient and safer nuclear reactor structural materials.

Recommendations

Based on the findings of this study, the following recommendations are made:

Further research is needed to investigate the effect of different roller processes on the micro structure and steel hardness of 15% CR-25% NI steel.
The development of new techniques in welding and material treatment is necessary to maximize the performance of nuclear reactor structural materials.
The use of advanced characterization techniques, such as SEM and EDS, is recommended to gain a deeper understanding of the material's behavior under different conditions.

Future Directions

The study has opened up new avenues for research in the field of nuclear technology. Future studies can focus on the following areas:

Investigating the effect of different roller processes on the micro structure and steel hardness of 15% CR-25% NI steel.
Developing new techniques in welding and material treatment to maximize the performance of nuclear reactor structural materials.
Using advanced characterization techniques, such as SEM and EDS, to gain a deeper understanding of the material's behavior under different conditions.

Limitations

The study has some limitations that need to be addressed in future research. These include:

The study was limited to a single type of steel, and further research is needed to investigate the effect of different steel types on the micro structure and steel hardness.
The study was limited to a single roller process, and further research is needed to investigate the effect of different roller processes on the micro structure and steel hardness.
The study was limited to a single characterization technique, and further research is needed to investigate the use of advanced characterization techniques, such as SEM and EDS.

Conclusion

Q: What is the significance of understanding the effect of rollers on 15% CR-25% NI steel?

A: The significance of understanding the effect of rollers on 15% CR-25% NI steel lies in its potential application in nuclear reactors. The material's behavior under thermo-mechanical treatment and welding is crucial in determining its structural strength and resistance to extreme conditions.

Q: What are the main findings of the study on the effect of rollers on 15% CR-25% NI steel?

A: The main findings of the study include:

The micro structure in the base metal area (base metal) has an unorthodox characteristic, with the presence of carbide inclusion.
In the Heat-Affected Zone (HAZ) region, observations show that the grain's reporting, where the grain size is larger than the thermo-mechanically affected zone (TMAZ) area, which has a more uniform micro structure and smaller grains.
The value of steel hardness after the roller process has decreased.
The XRD test results show that the 15% CR-25% steel is the result of the roll process only containing one single phase, namely the phase-ƴ.

Q: What are the implications of the study's findings for the development of new techniques in welding and material treatment?

A: The study's findings have significant implications for the development of new techniques in welding and material treatment. The results suggest that the roll process has a significant impact on the micro structure and steel hardness of 15% CR-25% NI steel, and that new techniques can be developed to maximize the performance of nuclear reactor structural materials.

Q: What are the limitations of the study, and how can they be addressed in future research?

A: The study has some limitations that need to be addressed in future research, including:

The study was limited to a single type of steel, and further research is needed to investigate the effect of different steel types on the micro structure and steel hardness.
The study was limited to a single roller process, and further research is needed to investigate the effect of different roller processes on the micro structure and steel hardness.
The study was limited to a single characterization technique, and further research is needed to investigate the use of advanced characterization techniques, such as SEM and EDS.

Q: What are the potential applications of the study's findings in the field of nuclear technology?

A: The study's findings have significant potential applications in the field of nuclear technology, including:

The development of new techniques in welding and material treatment to maximize the performance of nuclear reactor structural materials.
The creation of more efficient and safer nuclear reactor structural materials.
The improvement of the structural strength and resistance of nuclear reactor materials to extreme conditions.

Q: What are the next steps in the research on the effect of rollers on 15% CR-25% NI steel?

A: The next steps in the research on the effect of rollers on 15% CR-25% NI steel include:

Further investigation of the effect of different roller processes on the micro structure and steel hardness of 15% CR-25% NI steel.
Development of new techniques in welding and material treatment to maximize the performance of nuclear reactor structural materials.
Use of advanced characterization techniques, such as SEM and EDS, to gain a deeper understanding of the material's behavior under different conditions.

Q: What are the potential benefits of the study's findings for the nuclear industry?

A: The study's findings have significant potential benefits for the nuclear industry, including:

Improved safety and efficiency of nuclear reactors.
Increased resistance to extreme conditions.
Reduced maintenance and repair costs.
Improved public perception and acceptance of nuclear power.

Q: What are the potential challenges and risks associated with the study's findings?

A: The study's findings have significant potential challenges and risks associated with them, including:

The development of new techniques in welding and material treatment may require significant investment and resources.
The use of advanced characterization techniques, such as SEM and EDS, may require specialized equipment and expertise.
The potential for errors or inaccuracies in the study's findings may impact the development of new techniques and materials.

Q: What are the potential future directions for research on the effect of rollers on 15% CR-25% NI steel?

A: The potential future directions for research on the effect of rollers on 15% CR-25% NI steel include:

Investigation of the effect of different steel types on the micro structure and steel hardness.
Development of new techniques in welding and material treatment to maximize the performance of nuclear reactor structural materials.
Use of advanced characterization techniques, such as SEM and EDS, to gain a deeper understanding of the material's behavior under different conditions.