ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,392,017, issued on Aug. 19, was assigned to NIPPON STEEL Corp. (Tokyo).
"Hot-stamping formed body" was invented by Yuri Toda (Tokyo), Shinichiro Tabata (Tokyo), Kodai Murasawa (Tokyo), Daisuke Maeda (Tokyo) and Kazuo Hikida (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A hot-stamping formed body has a predetermined chemical composition and includes microstructure which includes residual austenite of which an area ratio is 5% or more and less than 10%. Among grain boundaries of crystal grains of bainite and tempered martensite in the microstructure, a ratio of a length of a grain boundary having a rotation angle in a range of 55deg to 75deg to a ...