서지주요정보
철강 내의 비금속개재물과 미세조직이 용접강관의 품질에 미치는 영향에 관한 연구 = Effects of nonmetallic inclusions and microstructures on the quality of welded line-pipe steels
서명 / 저자 철강 내의 비금속개재물과 미세조직이 용접강관의 품질에 미치는 영향에 관한 연구 = Effects of nonmetallic inclusions and microstructures on the quality of welded line-pipe steels / 최종교.
저자명 최종교 ; Choi, Jong-Kyo
발행사항 [서울 : 한국과학기술원, 1985].
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소장정보

등록번호

4103454

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 8558

SMS전송

도서상태

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반납예정일

초록정보

The effect of nonmetallic inclusions and micro-structures on the mechanical properties and Hydrogen Induced Stress Corrosion Cracking (HISCC) of welded line-pipe steels have been investigated. Specimens were taken from the welded region of API Grade X-65 and J-55 fabricated by High Frequency Resistance Welding process. Mechanical properties have been examined by means of the measurement of Charpy V-notch impact energy and flattening height. HISCC tests were conducted in $H_2S$ saturated aqueous solution containg 5% NaCl and 0.5\% $CH_3COOH$ at the temperature of 35±2℃ using smooth U-bend specimens. In the present work, incubation and propagation periods for HISC Cracks have been differentiated by means of electric potential method. Calibration of crack length with potential difference was carried out with the least square curve fitting method introducing the new parameter. Ca-treated specimens exhibited not only the longer incubation period for HISC Cracks but also the higher resistance to crack propagation. This is due to the formation of calcium sulfides instead of easily deformable manganese sulfide. The mechanical properties, however, were slightly improved. In the case of pearlite reduced steels, the propagation rate was a little reduced, while the incubation period was prolonged, possibly due to the reduced portion of pearlite. This microstructural feature increased the Charpy V-notch impact energy and markedly decreased the flattening height. In the weldment of line-pipe steels, HISCC kinetics could be divided into the four distinct stages, namely incubation stage, initiation stage, unstable propagation stage, and stable propagation stage. In all specimens, HISC Cracks propagated with transgranular brittle cleavage fracture mode.

서지기타정보

서지기타정보
청구기호 {MMS 8558
형태사항 [iii], 68 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 수록
저자명의 영문표기 : Jong-Kyo Choi
지도교수의 한글표기 : 변수일
지도교수의 영문표기 : Su-Il Pyun
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 37-42
주제 Steel.
Microstructure.
Stress corrosion.
Metals --Mechanical properties.
Metals --Inclusions.
미세 구조. --과학기술용어시소러스
비금속 개재물. --과학기술용어시소러스
응력 부식. --과학기술용어시소러스
기계적 성질. --과학기술용어시소러스
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