ข้อมูลผลงานวิจัย

Thermite welding is one of the selected methods used in the railway construction and maintenance. During thermite welding, it is very important to properly choose welding process parameters to avoid or minimize fracture and fatigue failures at welded joints during the usage, which causes waste of time and maintenance cost in addition to the delay in train schedule. In this study, two sets of thermite welding specimens were performed. In Case 1, the slag of thermite welded specimen was sheared off and removed using the current practice performed in the field welding, while in Case 2, the slag of thermite welding specimen was sheared off and removed after the temperature dropped below 200oC, in which the joint is more likely to be more ductile, and thus more suitable for real use in the field. For the microstructure study, the grain size of the case 1 specimen is larger and seemed to be contaminated, while the grain size of the case 2 specimen appears to be finer and has higher hardness. The microstructure appears to be pearlite structure in both specimens.