MUMBAI, India, June 24 -- Intellectual Property India has published a patent application (202617062815 A) filed by Jfe Steel Corporation on May 18, 2026, for Shape Memory Steel Sheet And Method For Manufacturing Same.
Inventors include Endoh Kazuki; Yoshitomi Hiromi; and Toji Yuki.
The application for the patent was published on June 12, 2026, under issue no. 24/2026.
Abstract: Provided are a shape memory steel sheet having a sufficient shape recovery strain amount, and a method for manufacturing the same. This shape memory steel sheet contains, in terms of mass%, 0.30-1.50% of C and 15.0-35.0% of Ni, and is such that the compositions of Si, Mn, P, S, Al, N, O, and the like are adjusted, wherein: the metal structure before a sub-zero treatment has an austenite content of 80% or greater and a graphite content of 15% or less in area ratio at a position of 1/4 of the sheet thickness; a part of the austenite is transformed into martensite by the sub-zero treatment; the martensite contains {112} twin crystals therein; the {112} twin crystals have a width of 50 nm or less; and the martensite is such that the value obtained by dividing the c-axis length of the crystal lattice (bct: body-centered square lattice) by the a-axis length thereof is greater than 1.00, the sub-zero treatment being a treatment in which the steel sheet is held in liquid nitrogen for 2 hours.
Disclaimer: Curated by HT Syndication.
