빙해선박용 강재의 저온특성에 관한 연구

• Published in: 大韓造船學會 論文集 Vol. 48; no. 2; pp. 171 - 177
• Main Authors: 민덕기(Dug-Ki Min), 심천식(Chun-Sik Shim), 신동완(Dong-Wan Shin), 조상래(Sang-Rai Cho)
• Format: Journal Article
• Language: Korean
• Published: 대한조선학회 2011
• Subjects: 조선공학; Steel for marine use(박용강재); Tensile test(인장실험); True fracture strain(진파단변형률); Low temperature(저온); True stress- true strain relationship(진응력-진변형률 관계); -
• ISSN: 1225-1143; 2287-7355

Tensile tests were conducted at low temperatures for the steel materials which are used for outer shell of the vessels making transit through the polar regions. The selected steel materials were GL-DH32, GL-DH36 and GL-EH36. In comparison with the results at room temperature, the yield stress increases approximately by 10 to 13 percent at $-30^{\circ}C$ and by 13 to 19 percent at $-50^{\circ}C$ while the tensile strength increases about by 9 percent at $-30^{\circ}C$ and 11 to 14 percent at $-50^{\circ}C$. To obtain true stress-true strain, i.e. correct plastic hardening characteristics, Bridgman's(1952) necking correction formula was introduced taking triaxial state of stresses after onset of diffuse necking into consideration. Photographs of fractured surfaces were taken by using Scanning Electron Microscope immedately after tensile tests completed and one for GL-EH36 has been presented in this paper.