Investigation of The Mechanism Failures of High Temperature Components Occurring Inside Boiler Tubes

This paper focused on the thermal mechanical fatigue failures inside the boiler tubes. These are caused by the various temperatures used in different tubes components and troubleshooting of boilers related to the principle of natural circulation. Inadequate circulation causes tube failures. This is usually due to design defects or improper boiler operation. In this paper, the factors affecting circulation are also summarized. Several thermal Mechanical Fatigue failure tube experiments were conducted and analyzed with the use of metallurgical Microscope. When selecting material to be used, it is crucial to consider the chemical contents that are found inside the alloys and used for boiler tubes to be original, which is the reason why it is important to use the original equipment(tube) manufacturer. The research study investigated the correct mechanism solution for one of the failure mechanisms, (Thermal Mechanical Fatigue) inside the boiler. The primary cause of the mechanism failure is how the boiler started to operate every time it was off. This is very critical because when the boiler is started, the lightening-up rate of the boiler must not be accelerated too much as this might cause an unnecessary overstrain of the boiler material by quick and uneven temperature rises. It was found to be necessary to perform several start/stop sequences to reduce the light-up rate. The hardness values for the base metal were obtained, analyzed, and found to be well within the tolerances as per specification. The hardness testing on the weld was higher than that of the base metal. It is important to perform chemicals inside the tubes, this also assists with obtaining internal clean tubes during operations