The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 2021
Filed:
Sep. 29, 2017
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Yasushi Hasegawa, Tokyo, JP;
Hirokazu Okada, Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A method of manufacturing a welded structure of a ferritic heat-resistant steel is provided that prevents Type IV damage and that has good on-site operability without adding a high B concentration. The method includes: the step of preparing a base material including 8.0 to 12.0% Cr, less than 0.005% B and other elements; the step of forming an edge on the base material; a pre-weld heat treatment step in which a region located between a surface of the edge and a position distant from the surface of the edge by a pre-weld heat treatment depth of 30 to 100 mm is heated to a temperature of 1050 to 1200° C. and is held at this temperature for 2 to 30 minutes; a welding step in which the edge is welded to form the weld metal; and a post-weld heat treatment step in which a region located between the surface of the edge and a position distant from the surface of the edge by a distance not smaller than the pre-weld heat treatment depth and not greater than 100 mm is heated to a temperature of 720 to 780° C. and is held at this temperature for a time period not shorter than 30 minutes and satisfying the following formula, (1):(Log()+12)·(+273)<13810  (1).