http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Cr-Mo-V강(T24)의 재현 HAZ의 결정립 성장에 미치는 피크온도의 영향
이경운(Kyong-woon Lee),이성형(Seong-hyeong Lee),나혜성(Hye-sung Na),강정윤(Chung-Yun Kang) 대한용접·접합학회 2016 대한용접·접합학회지 Vol.34 No.6
Recently developed ferritic heat resistance steel, T24 was used to evaluate microstructure characteristics of simulated heat affected zone. Also, correlation between the prior austenite grain size and amount of M23C6 carbide dissolution was discussed. With the increasing of peak temperature, Grain size steadily increased up to 1050℃ and then rapidly increased at 1150℃. Of the peak temperature 950~1050℃, amounts of M23C6 carbide dissolution are low. But Most of M23C6 carbide that is inhibited grain growth were dissolved above 1050℃ and decreased volume fraction of carbide. This indicates that grain growth may be achieved through dissolution of carbide in the base material. As of welding, due to very rapid heating rate, M23C6 carbide exists above equilibrium solution temperature that is 800℃, even at 1050℃. So, It was confirmed that close correlation between carbide dissolution in the base material and grain growth. Calculated grain size has a linear relationship with peak temperature, on the other hand, measured grain size discontinuously increased between 950~1050℃ and above 1050℃. Grain size of heat affected zone at 1350℃ peak temperature showed maximum 67um and minimum 4um. Also, The number of side showed 3 to 10.
석탄화력발전소 보일러 배관용 9Cr-2W계 강의 피로 및 크리프 파단 특성
이연수(Lee Yeon-Soo),유석현(Ryu Seog-Hyun),공병욱(Kong Byeong-Ook),이경운(Lee Kyong-Woon),김정태(Kim Jeong-Tae),백정웅(Baek Jeong-Woong),남수우(Nam Soo-Woo) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.8
Low cycle fatigue and creep rupture properties have been investigated in welded joint of P92 steels for USC thermal power plant. According to the result of continuous Jow cycle fatigue test, fatigue life of base metal was longer than that of weld metal and HAZ with the temperature range. The fatigue life of creep-fatigue interaction test with 10min. hold time was shorter values by accelerated recovery phenomenon in comparison with continuous low cycle fatigue life. The creep rupture strength of cross weld was lower than that of base metal. Fracture position of cross weld after creep was located between FCHAZ and ICHAZ and change of fracture appearance was occurred from ductile to brittle mode at test temperature of 650℃.
김천석,김은규,박진,이경운,Kim, Cheon-Seog,Kim, Yeun-Gue,Park, Jin,Lee, Kyong-Woon 대한흉부심장혈관외과학회 1997 Journal of Chest Surgery (J Chest Surg) Vol.30 No.10
폐쇄식 흉강 삽관술은 흉부외과 영역에서 가장 많이 사용하는 수기로, 기흉 등의 여러 흉부질환과 흉부외 상 또는 흉부 술후에 적용된다. 조선대학교 의과대학 병원에서는 1991련 1월부터 1996년 12월까지 만 6년간 흉부 술후에 흉관을 거치한 경우를 제외한 례쇄식 흉강 삽관술 2341예를 시행하였다. 총 234떼중 남녀 비는 3.5:1, 연령별 분포는 남자 $36.6\pm21.0세,$ 여자 $47.3\pm20.2세로$ 전체평균 $40.0\pm20.5세$ 였으며, 적응증은 자연성, 이차성 및 외상성 기흉(39.4%)이 가장 많았고, 그 외에 혈흉, 혈기흉, 수흉, 수기흉, 농흉, 유미흉 등이었다. 흉관의 거치기간은 8714일이 974예(41.6%)로 가장 많았고, 평균 $13.7\pm6.3일$ 이었다. 상관후 배액량은 전체 평균 $537\pm88m1,$ 그리고 201~500ml가 694예(46.0%)로 가장 많았다. 상관의 우-좌비는 52.4:47.6이었고, 처음 상관한 경우가 2071예(88.5%)였으며, 1개만 삽관한 경우가 2210예(94.4%)였다 합병증은 거의 모든 환자에서 삽관부 동통(99.8%)을 호소하였으며, 그 외에 삽관부 감염, 늑간신경통, 흉막유착으로 인한 흉관기능의 상실, 흉강내 감염, 폐의 불완전 재팽창, 혈관손상으로 인한 출혈, 피하기종, 폐실 \ulcorner파열, 횡격막 및 복강내 손창, 일측폐의 재팽창성 폐부종 그리고 봉소염 등이 발생하였다. 삽관술 만으로 회복된 환자는 1981예(84.6%) 였 으며, 더 이상의 외과적 처치가 필요한 경우는 226예(9.7%)였다. 사망한 경우는 2예(0.1%)로, 재팽창성 폐부종 1예와 농흉 환자에서 흉강 상관후 봉소염이 병발하여 패혈증으로 사망하였다. Closed thoracostomy with UWSD* which is the most utilized procedure in chest surgery applies general thoracic disorders, trauma and after-thoracic surgery. The University hospital was involved on operating 2341 cases of closed thoracostomy with UWSD except chest tubing after-thoracic surgery for a full six years from January, 1991 to December, 1996. The rate of men and women out of the total 2341 cases was 3.5 : 1, the distribution by age showed that men were 36.6 $\pm21.0$ years old, women were $47.0\pm20.2$ years old and so that the total were 40.0 $\pm$ 20.5 years old. As for indication, spontaneous, secondary and traumatic pneumothorax were the most common, in addition to hemothorax hemopneumothorax, hydrothorax, hydropneumothorax, empyema, chylothorax. The most indwelling period of chest tubing is between eight and fourteen days for 974 cases and the average is 13.7 $\pm$ 6.3 days, The average drainage amount immediately after thoracostomy was 537 $\pm$ 88m1, and in 694 cases(46.0%), the drain amount was 201 ~ 500 ml. The rate of right and left tubing was 52.4 47.6, in 2071 cases(88.5%), the thoracostomy was the first chance and 2210 cases(94.4%) were treated with a single tube drainage. Almost all the patients complained of tube site pain, besides tube site infection, intercostal neuralgia, loss of tube function by the pleural adhesion, intrathoracic infection, incomplete reexpansion of defective lung, hemorrhage caused by the rupture of a blood vessel, subcutaneous emphysema, lung parenchymal rupture, diaphragmatic and intraabdominal trauma, reexpansionary pulmonary edema of one side lung and cellulitis were relapsed. 84.6% of all patients recovered with only clo ed thoracostomy and the rest of patient needed additional some necessary managements and so on to have successful results. There were two deaths(0.1%), caused by reexpansionary pulmonary edema, the cellulitis were complicated by thoracostomy with UWSD on an empyema patients to come to death(due to sepsis). t UWSD = under water seal drainage
Inconel 740H 니켈기 초내열합금과 TP316H 스테인리스강의 이종금속 SMA 용접부의 미세조직과 크리프 파단 특성
신경용(Kyeong-Yong Shin),이지원(Ji-Won Lee),한정민(Jung-Min Han),이경운(Kyong-Woon Lee),공병욱(Byeong-Ook Kong),홍현욱(Hyun-Uk Hong) 대한용접·접합학회 2016 대한용접·접합학회지 Vol.34 No.5
The microstructures and the creep rupture properties of dissimilar welds between the Ni-based superalloy Inconel 740H and the non-stabilized austenitic stainless steel TP316H have been characterized. The welds were produced by shielded metal arc (SMA) welding process with the AWS A5.11 Class ENiCrFe-3 filler metal, commonly known as Inconel 182 superalloy. Postweld heat treatment at 760 ℃ for 4 hours was conducted to form γ΄ strengthener in Inconel 740H. The austenitic weld metal produced by Inconel 182 had a dendritic microstructure, and grew epitaxially from the both sides of Inconel 740H and TP316H base metals. Since both Inconel 740H and TP316H did not undergo any solid-state transformation during welding process, there were no heat-affected-zone (HAZ) sub-regions and the coarsoned grains near the weld interface were limited to a narrow region. The hardness of Inconel 182 weld metal was ~220 Hv. The gradual hardness decrease was detected at HAZ of TP316H, and the TP316H base metal displayed the lowest hardness value (~180 Hv) whilst the Inconel 740H showed the highest hardness value (~400 Hv). Fracture after creep occurred at the center of weld metal, regardless of creep condition. It was found that during creep the cracks initiated and propagated along interdendritic regions and grain boundaries at which Laves particles enriched in Nb, Si and Cr were present. The appropriate design of weld metal was discussed to suppress the creep-induced cracking of the present dissimilar weld.
발전용 저탄소 ASTM A356 CA6NM 마르텐사이트계 스테인리스 주강의 용접성
방국수 ( Kook Soo Bang ),박찬 ( Chan Park ),이주영 ( Jong Young Lee ),이경운 ( Kyong Woon Lee ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.1
Weldability, especially HAZ cold cracking, weld metal solidification cracking, and HAZ liquation cracking susceptibilities, of ASTM A356 CA6NM martensitic stainless steel casting was investigated and compared with that of 9-12% Cr ferritic steel castings. Irrespective of the Cr and Ni content in the castings, the HAZ maximum hardness increased with an increase of carbon content. CA6NM steel, which has the lowest carbon content, had the lowest HAZ hardness and showed no cold cracking in y-slit cracking tests. CA6NM steel, meanwhile, showed the largest weld metal solidification cracking susceptibility in varestraint tests because of its higher amount of impurity elements, phosphorus, and sulfur. All castings investigated had good high temperature ductility in hot ductility tests and showed little difference in liquation cracking susceptibility.