ALEXANDRIA, Va., July 16 -- United States Patent no. 12,358,036, issued on July 15, was assigned to NIPPON STEEL Corp. (Tokyo).
"Hot-stamping formed body" was invented by Yuri Toda (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 10% or more and less than 20%. Among grain boundaries of crystal grains of bainite and tempered martensite, a ratio of a length of a grain boundary having a rotation angle in a range of 55deg to 75deg to a total length of a grain boundary having a rotati...