Abstract
Taking up the TMCP type low-temperature carbon steel plate (equivalent to SLA33B and SLA37 steels) and the TMCP type low-temperature low-Ni steel plate (equivalent to SLA37 steel) recently developed for practical use as new structural steels, this report discusses the strength properties of these steels with an emphasis on fracture toughness of the base metal as well as of the high heat-input welded joints therein produced, the gists of which may be encapsulated as follows. (1) Articulating excellent strength properties of the TMCP type low-temperature steel plates, the authors make a point among others of the extraordinary brittle crack propagation arrest characteristics of the steels. (2) The authors endorse adequately high toughness offered by high heat-input welded joints of the steels even at temperatures of as low as -50 to -60℃. (3) Also, the authors confirmed that the steels can fully be used for such heavy structures as cryogenic LPG storage tanks, north-sea marine structures, etc.
