US 12,345,623 B2
Method for evaluating delayed fracture of metal material
Naho Inoue, Tokyo (JP); Shinji Otsuka, Tokyo (JP); Daisuke Mizuno, Tokyo (JP); and Nobuyuki Ishikawa, Tokyo (JP)
Assigned to JFE STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/635,876
Filed by JFE STEEL CORPORATION, Tokyo (JP)
PCT Filed Jun. 10, 2020, PCT No. PCT/JP2020/022932
§ 371(c)(1), (2) Date Feb. 16, 2022,
PCT Pub. No. WO2021/033397, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 2019-149324 (JP), filed on Aug. 16, 2019.
Prior Publication US 2022/0291113 A1, Sep. 15, 2022
Int. Cl. G01N 17/02 (2006.01); G01N 17/00 (2006.01)
CPC G01N 17/02 (2013.01) [G01N 17/006 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A method for evaluating a delayed fracture characteristic of a metal material, the method comprising:
bringing an aqueous solution comprising a chloride ion into contact with a surface of the metal material such that chloride in an amount of from 1000 to 100000 mg/m2 is deposited on the surface thereof, and
leaving the metal material stationary in an air atmosphere at a temperature from −50 to 10° C. and at a relative humidity higher than or equal to a deliquescence humidity of the chloride,
wherein the bringing and the leaving are performed once or a plurality of times to evaluate the delayed fracture characteristic of the metal material, and
wherein the method does not include a drying step where a humidity in the air atmosphere is lower than the deliquescence humidity of the chloride.