• Journal of the Korean Society for Heat Treatment
• /
• v.18 no.3
• /
• pp.164-171
• /
• 2005

Iodine-Induced Stress Corrosion Cracking (ISCC) properties of Zircaloy-4 and HANA4 developed in KAERI for the high burn-up nuclear fuel cladding were evaluated. To confirm the effect of final heat treatment on ISCC resistance of Zr-alloy, stress relieved and recrystallized specimens were prepared and tested. With the pre-cracked specimen at internal surface, ISCC crack propagation rates and threshold stress intensity factor ($K_{ISCC}$) based on the fracture mechanics were measured by internal pressurization test at $350^{\circ}C$ in iodine environment. $K_{ISCC}$ of Zircaloy-4 and HANA4 cladding were $3.3MPa{\cdot}m^{1/2}$ and $4.4MPa{\cdot}m^{1/2}$, respectively. Pitting corrosion at the crack surface was observed and it seemed that TG crack propagation was derived from the pitting.

• Corrosion Science and Technology
• /
• v.3 no.1
• /
• pp.14-19
• /
• 2004

Crack growth rate and threshold stress intensity factor for stress corrosion cracking(SCC), $K_{ISCC}$ were measured for type 403 stainless steel in 3,5% NaCl solution at room temperature and SCC was monitored by electrochemical noise technique during $K_{ISCC}$ testing. In rising load test, pits were formed at the tip of pre-crack for the pre-cracked compact tension specimen unlike in smooth round specimen in which only unstable pits were observed and hence immune to SCC. Micro-cracks were found to initiate from the pits in the former specimen, and initiation of micro-crack as well as macro-crack was detected by electrochemical noise technique in rising load $K_{ISCC}$ tests. Crack growth rate increased with increasing either displacement rate or stress intensity factor at crack initiation and was higher in rising load $K_{ISCC}$ test compared to constant load $K_{ISCC}$ test at given stress intensities.

• Corrosion Science and Technology
• /
• v.6 no.4
• /
• pp.170-176
• /
• 2007

Iodine-induced stress corrosion cracking (ISCC) properties and the associated ISCC process of Zircaloy-4 and an Nb-containing advanced nuclear fuel cladding were evaluated. An internal pressurization test with a pre-cracked specimen was performed with a stress-relieved (SR) or recrystallized (RX) microstructure at $350^{\circ}C$, in an iodine environment. The results showed that the $K_{ISCC}$ of the SR and RX Zircaloy-4 claddings were 3.3 and 4.8MPa\;m^{0.5}, respectively. And the crack propagation rate of the RX Zircaloy-4 was 10 times lower than that of the SR one. The chemical effect of iodine on the crack propagation rate was very high, which was increased $10^4$ times by iodine addition. Main factor affecting on the micro-crack nucleation was a pitting formation and its agglomeration along the grain boundary. However, this pitting formation on the grain-boundary was suppressed in the case of an Nb addition, which resulted in an increase of the ISCC resistance when compared to Zircaloy-4. Crack initiation and propagation mechanisms of fuel claddings were proposed by a grain boundary pitting model and a pitting assisted slip cleavage model and they showed reasonable results.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2003.05a
• /
• pp.231.2-231.2
• /
• 2003

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.10a
• /
• pp.237-237
• /
• 1998

• Archives of design research
• /
• no.16
• /
• pp.89-98
• /
• 1996

The purpose of this study is to offer proposals of the practical color schemes based on the use of color systems. This study focused on the .\lunsell color system, the Ostwald color system and the ISCC ~BS color names i and then selected the Ostwald color harmony and the Judd color hallTIOny in order to establish the general principles of color schemes. The method of color schemes is worked by' the 10 i hues circle of the .\Iunsell color system and the tone system of the ISCC :\BS color names, because our i country have been adopted the "vIunsell color system for the use of color education and the KS. This method is to make the balanced color schemes easily and effectively through color education ..olor education ..

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05c
• /
• pp.188-192
• /
• 1996

재결정 Zircaloy-2의 요드에 의한 응력부식균열의 전파속도를 직류전압강하측정법 (DCPD, Direct Current Potential Drop)을 이용하여 측정하고 임계응력집중계수( $K_{ISCC}$)를 구하였다. 임계요드농도 이상인 0.01 MPa의 요드농도에서, $K_{ISCC}$는 300 $^{\circ}C$의 경우 약 15 MPa√m, 350 $^{\circ}C$의 경우 약 12 MPa√m의 응력계수였으며, plateau 구역에서의 균열속도는 $10^{-4}$~ $10^{-3}$ mm/sec 영역이었다.

• Journal of Ocean Engineering and Technology
• /
• v.4 no.1
• /
• pp.88-100
• /
• 1990

Among the test methods to evaluate stress-corrosion cracking(SCC) on the basis of fracture mechanics, constant displacement(bolt) loading method using modified-WOL specimen is practically convenient. In this test method, compliance formula is generally required to calculate load(consequently $K_{ISCC}$). There are many problems in using the analytic compliance formula to calculate $K_{ISCC}$, so we had proposed the experimental $K_{ISCC}$ evaluation technique in the previous report. This study has employed the slightly altered configuration of modified-WOL specimen made of weldable structural stee(BS360-50D). With these specimens, stress-corrosion tests have been performed in $H_2S$ gas saturated 20% HCl solution. Through the test, the problems as mentioned earlier have been discussed again, and the proposed evaluation technique has been verified. And the stress-corrosion cracks and hydrogen blisters have been investigated in the initiation step with the aids of metallurgical micrographs, SEM fractographs, and EPMA analysis. The inclusions segregated in the mid-thickness region traps hydrogen to produce the hydrogen blistering. The applied or residual stress does not contribute the occurrence of the blister. Hydrogen absorbed into the mid-thickness region is consumed to produce the blistering so that stress-corrosion crack could hardly be detected at that region. The stress-corrosion cracks initiate from the inclusions and propagate in radial pattern. And the initiation site is remote from the crack tip and is inclined from the crack plane, which is assumed to be caused by the triaxial stress and the amount of the absorbed hydrogen.

• Fashion & Textile Research Journal
• /
• v.6 no.3
• /
• pp.285-296
• /
• 2004

Fashion business must reflect the seasonable fashion trend because fashion has change always, and therefore fashion business has a big risk at the attribute. Careful consideration should be given to the selection of a particular color code to meet the purpose of marketing research in various color products. It must be designed to grasp systematically and comprehensively the current trend of colors. The most suitable color code for meeting this proposition would be one based on the designation by color ranges. The ISCC-NBS method of designating colors, published in 1955, was established by dividing the color solid into 267 color name blocks. The detailed classification like the ISCC-NBS system is very appropriate to serve the purpose of giving all color names according to color ranges. But it is somewhat too complicated to answer the purpose of surveying the trend of colors and of comparing and evaluating the ups and downs in the popularity of the range of each individual color. I have worked out the most convenient method of designating colors in accordance with the type of investigation needed. It is the classification which involves four classification system in itself, fundamental, gross, medium, and minute. The fundamental classification system classifies hues and neutrals into 16ranges. The gross classification system divides the above 16 ranges into 30. The medium classification divides the above 30 ranges into 103 in terms of tones. The minute classification divides the above 103 ranges into 207 in terms of specipic hues.

• Archives of design research
• /
• v.16 no.3
• /
• pp.161-174
• /
• 2003

Choice and use of color are very important field for designer. Present color sprang by central field of design business unlike past. Color is used mainly by three fields of sensitivity, administration, mind. But, do substantial design including all of three fields at use. Practical research field that is based on basic research when see as actuality of domestic color design is been behind real condition. Specially, color sensitivity field and color management field are very important field, it can speak that color name arid related area are most important among two. Because collar name includes sensitivity and color management. This research constructs correct data because investigate and analyze and search all compatible color names that is announced in existing or is recorded in public cosmopolitanly. As a result, it is to promise accuracy when produce creation of idea and result of design using color name. Examined laying stress on color that domestic data that is used in research is basis with Korean industrial Standard, connection literature, on-the-spot probe. International data investigated American ISCC-NBS to base. Other abroad color name data examined official data of each country all systematically with Japan, Europe. Findings about 11,000 basis color names and 33,000 application color names sorted collection. Collection method and classification system follow in international standard and arranged for user's tile convenience. Also, use frequency did laying stress on Munsell that is high color system so that can aid in industrial design business. Improved to write all international standard color values sue as RGB, CMYK, XYZ and can be applied all in each field of design. Is applying and get along with continuation improvement and development in homepage of present KIDP, it may become more worth research.