http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
알루미늄의 첨가와 열처리가 연강의 응력부식성질에 미치는 영향
김신,변수일 한국부식학회 1981 Corrosion Science and Technology Vol.10 No.1
The effects of Al addition and heat treatment on the stress corrosion behaviour of mild steel (0.03∼0.04%) in the aqueous solution containing 860g Ca(NO₃)₂ 4H₂O and 30g NH₄NO₃ per liter of solution was studied at the boiling temperature (11℃) using constant strain method (U-bend specimen). The resistance to SCC (stress corrosion cracking) of mild steel was studied with various Al contents of 0%, 0.04%, 0.45%, 0.65%, 0.96%, 1.28% and 1.52% by weight after annealing at 1150℃ for 1h, then furnace-cooled to room temperature. The effect of heat treatments (furnace-cooled, oil-quenched, water-quenched, and water-quenched then tempered at 500f7 for 1h) m the resistance to SCC was studied with the specimens of 0.04% and 0.45% Al content. Induction period, crack propagation period and rate were determined by extrapolation of measured maximum crack depth at different exposure time to the corrosive environment. In this study incluction period and crack propagation rate are considered to be toe measure of resistance to SCC of mild steel. All specimens showed 1 or up to 3 crack on an U-bend specimen which propagated along grain boundary (intercrystalline SCC). For furnace-cooled specimens the resistance to SCC increased as Al content increased from 0% up to 0.65%, then decreased up to 1.52% Al. The two staged variation of the resistance to SCC in mild steel was discussed in terms of tendency of Al nitride formation and grain size of specimens respectively. Tempered specimens with Al contents 0.04% and 0.45% skewed higher resistance to SCC than water-quenched and this is considered to be due to the decrease in carbon concentration at the grain boundary.
안동댐과 임하댐 유역에서 퇴적물 특성 및 오염도의 시·공간적 변화
김신,정현기,김형근,김주언,박수정,김용석,양득석,Kim, Shin,Jeong, Hyun-Gi,Kim, Hyoung-Geun,Kim, Ju-Eon,Park, Su-Jeong,Kim, Yong-Seok,Yang, Deuk-Seok 한국환경과학회 2019 한국환경과학회지 Vol.28 No.12
We investigated the spatial and temporal variation in characteristics and pollution assessment of sediments in the watersheds of Andong-Dam and Imha-Dam, in Korea. Surface sediments were collected from six sites once a year for three years (2015-2017), and analyzed for organic matter (water content, IL, COD, TOC, TN, and TP), grain size, and concentration of trace metals (Al, Li, Zn, Cr, Pb, Cu, Ni, and As). Organic matter generally tended to increase, and was higher in the Andong watershed compare to Imha watershed. Surface sediments were mainly composed of silt. Coarse sediments were mainly distributed at the site adjacent to Andong-Dam, and showed fining after coarsening. Fine sediment were mainly distributed at the site adjacent to Imha-Dam, and were gradually coarsening. Concentration of trace metals generally tended to increase, and was higher for sites in watershed of Andong watershed (PLI > 1) than for sites in Imha watershed (PLI < 1). Trace metals in the study area were considered to be affected by fine sediment (silt), and contamination of trace metals was somewhat affected by Pb, and greatly affected by Zn and As.