SEARCH RESULT

-In this study, termite welding process was applied to R260 quality railway rails. Residual stress of original and termite welded rails was measured according to the DIN EN 13674-1 standard. Strain gauges were attached in the middle of the rail foot (also welded part of rail). Cutting was performed than strain values were obtained. Wear test was also performed under 50N. Results show that, residual stress was increased after the welding process and wear rate value was lower than original rails in head part of termite welded rail.

International Iron & Steel Symposium
UDCS

Harun ÇUĞ M. Emre TURAN Mustafa DURSUNLAR

In this study, head hardening process was applied for R260 quality rails. Microstructures of rails were carried out using Scanning Electron Microscope (SEM). Hardness distribution of head parts were also evaluated for two category samples (heat treatment and non heat treatment). Wear tests were performed under three different loads (10N, 20N and 40N) in both %3.5NaCI solution and dry conditions. Worn surfaces were characterized by Nikon Shuttlepix, Profile projector and SEM. Results clearly show that, head hardened rails exhibited better wear performance especially under load of 10N in dry conditions.

International Iron & Steel Symposium
UDCS

M. Emre TURAN Fazil Hüsem Yasin Akgül Yavuz Sun Hayrettin Ahlatçı

In this study, heat treatment was applied for four 1040 quality steels and then cooling process was performed in different conditions. One of the specimens was cooled in furnace and the other specimens were cooled in air, oil and water respectively to determine the effect of cooling conditions on fracture toughness. Fracture and precrack surfaces were examined by Nikon Shuttlepix Digital microscope during analysis and Scanning Electron Microscope(SEM) after fracture toughness measurement. Results show that, cooling conditions significantly effect the fracture toughness value of specimens.

International Iron & Steel Symposium
UDCS

M. Dikmen M. Emre TURAN

This study aims to investigate fatigue crack growth and fracture toughness behavior in grooved rails. R260 grade and R260 grooved grade rails were used for analysis to understand effect of rail geometry on fracture properties of specimens. Fracture surfaces and microstructures of specimens were examined by the use of Scanning Electron Microscope(SEM) and Nikon Shuttlepix Digital Microscope. Results show that, fracture toughness and fatigue crack growth behavior are effected by the geometry of specimens due to plastic deformation mechanism on head parts.

International Iron & Steel Symposium
UDCS

Fazil Hüsem M. Emre TURAN Hayrettin Ahlatçı

This study aims to determine residual stress distribution in head, web and foot parts of two different quality grooved rails and also to understand effect of carbon content on residual stress in rails. Strain gauges were glued on three regions of specimens and cutting method was applied for residual stress measurement according to the TS EN 13674-1 railway rail standard. Scanning Electron Microscope (SEM) and Optic Microscope (OM) were used for microstructure analysis of regions where the residual stress measurements were performed. Results show that, compressive residual stress is an effective stress type compared to the R260 grade rails. However, R260 grade grooved rails have higher residual stress value than R220 grade grooved rails especially in head parts of specimens.

International Iron & Steel Symposium
UDCS

M. Emre TURAN Yavuz Sun Fazil Hüsem

The aim of this study is to investigate the effect of nitration and nitrox process on wear performances of tool steels. For this purpose, samples were seperated as two categories. One group was exposed to nitration process in salt bath at 530 0C during 6 hours. For other group, nitrox process was applied at 4900C during 2 hours after nitration. Reciprocating wear test was performed for all specimens under the loads of 10N, 20N and 40N according to the ASTM G99 standard. Microstructures and worn surfaces of specimens were analysed using Scanning Electron Microscope (SEM). Results show that, wear performances of specimens exhibit difference when they are exposed nitration and oxidation process. And also they show better performance under the lower loads.

International Iron & Steel Symposium
UDCS

M. Emre TURAN Mustafa ACARER M.Karakus Hayrettin Ahlatçı Yunus Türen Yavuz Sun