Title:
MEASURING METHOD OF RESIDUAL STRAIN, AND MEASURING METHOD OF RESIDUAL STRAIN OF GRAPHITE MATERIAL FOR NUCLEAR REACTOR UTILIZING THE METHOD
Document Type and Number:
Japanese Patent JP3022235
Kind Code:
B2
Abstract:
PURPOSE: To measure a residual strain of a graphite material in a nuclear reactor easily without destructing a measuring material, by utilizing a difference in the deformation resistance of the material between a state wherein the residual strain is brought about and a state wherein it is not brought about.
CONSTITUTION: Attention is paid to that when there is nonlinearity in a stress-strain curve of a material, a gradient of the curve at a point A where a residual strain is not present differs from the one at a point B where a certain residual strain is present and that a deformation resistance at the point A where the gradient is large is larger than the one at the point B where the gradient is small. Regarding a graphite material for a nuclear reactor, an indentation load and an indentation depth are measured for each residual strain level by using an indentation hardness tester and the hardness of the material is determined. Thereby the relation between the residual strain and the indentation depth or a correlation diagram of the residual strain and the hardness is determined. By examining the indentation depth or the hardness by taking out the graphite material from the nuclear reactor or by inserting a measuring part of the hardness tester into the nuclear reactor when the material is left therein as it is, the residual strain of the material can be measured without destructing the material.
Inventors:
Masahiro Ishihara
Application Number:
JP4720495A
Publication Date:
March 15, 2000
Filing Date:
March 07, 1995
Export Citation:
Assignee:
Japan Atomic Energy Research Institute
International Classes:
G01B5/30; G01N3/42; G21C17/06; (IPC1-7): G01N3/42; G01B5/30; G21C17/06
Domestic Patent References:
| JP579928A |
Attorney, Agent or Firm:
Kazuo Shamoto (5 outside)