High-toughness, high-tensile-strength steel and method of manufacturing the same
CA 2230396 C · Owner: Komizo, Yu-Ichi · Inventors: Komizo, Yu-Ichi; Okaguchi, Shuji; Fujiwara, Kazuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
High-tensile-strength steel having excellent arrestability and a TS of not less than 900 MPa as well as a method of manufacturing the same. The steel of the invention has the following composition (% by weight): C: 0.02% to 0.1%; Si: not greater than 0.6%; Mn: 0.2% to 2.5%; Ni: greater than 1.2% but not greater than 2.5%; Nb: 0.01% to 0.1%; Ti: 0.005% to 0.03%; N: 0.001% to 0.006%; Al: not greater than 0.1%; and optional elements. Ceq of the B-free steel is 0.53-0.7% and Ceq of the B-bearing steel is 0.4-0.58%. The microstructure of the steel may be a mixed structure of martensite (M) and lower bainite (LB) occupying at least 90 vol.% in the microstructure LB occupying at least 2 vol.% in …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed February 24, 1998 and granted November 20, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 24, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 24, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.