Papers by Author: Dong Ho Bae

Paper TitlePage

Authors: Dong Ho Bae, J.H. Park
Abstract: In order to develop a corrosion fatigue design method and estimate reliability of TMCP steel using as the material of heavy industries and plants, its electrochemical corrosion characteristics and determination of corrosion fatigue design criterion were investigated. And, a corrosion fatigue design method of TMCP steel was also investigated. From the results, the corrosion characteristic of TMCP steel is very susceptible in 3.5wt.% NaCl solution. Its susceptibility was linearly increased with the solution temperature increase. Corrosion fatigue strength in 25°C, 3.5wt.% NaCl solution is very lower than that of in air. And also, it was decreased with loading frequency decrease in the same environment. It was found that corrosion fatigue strength and life of TMCP steel is predictable by using the S-N curve of fatigue strength in air. Therefore, it is expected that the developed corrosion fatigue design method for TMCP steel will be useful for safe design and reliability assessment of the industrial facilities and structures.
1361
Authors: S.Y. Cho, Chang Hoi Kim, Dong Ho Bae
993
Authors: Dong Ho Bae, N. Tomioka, J. Niisawa, H. Kitagawa
441
Authors: Dong Ho Bae, Seong Cheol Jang, Gyu Young Lee
Abstract: In this paper, as a fundamental study to evaluate fracture characteristics and material degradation by corrosion, evaluated electrochemical corrosion and corrosion fatigue characteristics of CF8A steel using as a material of the piping system in nuclear power plant. CF8A steel was artificially degraded at 400°C for 3 months. The environmental test condition is 3.5wt.% NaCl solution of room temperature. Corrosion rate of degraded CF8A steel in NaCl solution of room temperature increases with concentration of NaCl solution increase. However, concentration of NaCl solution will be more than 4.0wt.%, it shows decreasing tendency. Crack growth rates of degraded and not-degraded CF8A steel in air condition do not show remarkable difference. However, in 3.5wt.% NaCl solution, crack growth rates of them showed higher than ones in air. Particularly, crack growth rate of degraded material remarkably increases compare to one of notdegraded material.
3
Authors: Seong Cheol Jang, Dong Ho Bae, Gyu Young Lee
Abstract: CF8A steel is a material of the piping system in nuclear power plant. In order to evaluate its fracture characteristics and degradation by corrosion, electrochemical corrosion and corrosion fatigue characteristics were evaluated. CF8A steel was artificially degraded at 400°C for 3 months. Corrosion rate of degraded CF8A steel in NaCl solution of room temperature increases with concentration of NaCl solution increase. However, concentration of NaCl solution will be more than 4.0wt.%, it shows decreasing tendency. Crack growth rates of degraded and not-degraded CF8A steel in air condition do not show remarkable difference. However, in 3.5wt.% NaCl solution, it showed higher than that of in air.
611
Authors: Byung Bok Choi, Dong Ho Bae
Abstract: Austenitic stainless steel is a useful material for various industrial facilities such as the nuclear and steam power plant and the heavy chemical industry due to its good corrosion resistance and mechanical properties. However, it has also a large problem that austenitic stainless steel is sensitized in the welding process and its corrosion resistance and mechanical properties decreases by sensitization. Thus, in this paper, corrosion fatigue characteristics of artificially sensitized austenitic STS304 were investigated through corrosion fatigue test. From the results, corrosion fatigue strength of sensitized STS304 was remarkably reduced compare to non-sensitized ones. And it is expected that corrosion fatigue life of TMCP steel can be nondestructively predicted using the DCPD method.
9
Authors: Dong Ho Bae, Byung Bok Choi, Gyu Young Lee
Abstract: Austenitic stainless steel has a large problem to decrease its corrosion resistance and mechanical properties by sensitization in the welding process. Thus, in this paper, corrosion fatigue characteristics of artificially sensitized STS304 were investigated. According as heat treatment period for sensitization increases, the Cr-carbide deposition in the grain boundary and degree of sensitization (Ia/Ir) increased. From the results, corrosion fatigue strength of sensitized STS304 was remarkably reduced compare to non-sensitized ones.
607
Authors: Dong Ho Bae, Won Seok Jung, J.B. Heo
Abstract: An effective way to reduce the weight of vehicle body seems to be application of new materials, and such trend is remarkable. Among the various materials for vehicle body, stainless steel sheets and cold rolled steel sheets are under the interests. However, in order to guarantee reliability of new material and to establish the long life fatigue design criteria for body structure, it is necessary to assess spot weldability and fatigue strength of spot welded lap joints fabricated under optimized spot welding condition. In this paper, spot weldability of stainless steel sheets, STS304L and STS316L, and cold rolled steel sheets, SPCC and SPCD. Fatigue strength of lap joints spot welded between similar and dissimilar materials were also assessed.
2883
Authors: Il Seon Sohn, Dong Ho Bae, Won Seok Jung, Won Wook Jung
Abstract: Suspension system of light commercial vehicle (LCV) has enough endurance to protect passenger and freight. Leaf spring is major part of LCV suspension system. Thus, fatigue strength evaluation of leaf spring based on road load response was carried out. At first, the strain of leaf spring was measured on the city mode driving condition and proving ground driving condition. And , the damage analysis of road load response was carried out. After that, fatigue test of leaf spring was also carried out. Based on ε-N life relation, fatigue life of leaf spring was evaluated at Belgian mode, city mode and drawing test specification called the 3 steps test mode. Next, it is compared the design life of leaf spring and evaluated fatigue life by the 3steps test mode. From the above, new target of Belgian mode and city mode was proposed to gratify design specification of leaf spring. It is expect that the proposed target can be satisfied leaf spring fatigue endurance at specific road condition.
322
Showing 1 to 10 of 26 Paper Titles