Analysis of Oxide Layers on T91 Pipe for Supercritical Boiler

• Main Author: Hanif, Akhyar
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/38563
• Institution: Institut Teknologi Bandung

The efficiency of boiler commonly used in power plants can be improved by increasing temperature and pressure of the process. Such boiler is called supercritical boiler. To achieve higher temperature and pressure in the process, sufficient material is needed such as SA 213 T91. Supercritical boiler is still new in the industry, therefore further study is needed to understand the characteristic of supercritical boiler. One of it is oxide layers inside the T91 tube. In this study various characterization method is done to used T91. The result shows that thickness of oxide layers in samples is measured at 139.91 ?m, 90.16?m, and 132.73 ?m. The difference is affected by temperature and oxygen content of working environment. Oxide layers of samples contains hematite, magnetite, and chromite because its thermodynamics requirement is fulfilled. Grain size of samples is measured at 8.95 ?m, 7.49 ?m, and 8.41 ?m. The difference is affected by the utilization duration of the pipe. Hardness on the inside part of the sample with the average of 196.7 HV is higher compared to outer part of the pipe with the average of 176.4 HV. The difference is caused by different working temperature between the inner and outer part of the pipe. Based on the results of characterization. It is concluded that sample 1 and 3 is used in superheater of supercritical boiler and sampel 2 is used in economizer of supercritical boiler