18836002. STEEL PLATE AND METHOD OF PRODUCING SAME (JFE STEEL CORPORATION)
STEEL PLATE AND METHOD OF PRODUCING SAME
Organization Name
Inventor(s)
Kyono Yasuda of Chiyoda-ku, Tokyo JP
Kazuhiko Shiotani of Chiyoda-ku, Tokyo JP
STEEL PLATE AND METHOD OF PRODUCING SAME
This abstract first appeared for US patent application 18836002 titled 'STEEL PLATE AND METHOD OF PRODUCING SAME
Original Abstract Submitted
A high strength steel plate having excellent ammonia SCC resistance and low-temperature toughness for use in storage tanks used to contain liquefied gas in energy transport ships. The steel plate has a defined chemical composition, and has hardness properties such that, at a 0.5 mm depth position from the surface of the steel plate, average hardness is 230HV0.1 or less and hardness variation is 30HV0.1 or less, a maximum value of hardness in the thickness direction is at a position 1.0 mm or more and ¼ or less of the thickness of the steel plate from the surface of the steel plate, and hardness variation in the thickness direction is 70HV1 or less. Further, the steel plate has a metallic microstructure where, at a 0.5 mm depth position from the surface of the steel plate, a volume fraction of bainitic microstructure is 90% or more.