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US 6,332,361 B1Granted
Method for evaluating bonding properties of a metallic pipe
AssigneeDaido Tokushuko Kabushiki Kaisha
InventorsRyuzo Yamada, Hirotsugu Horio, Takao Shimizu
Life of this patent
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Abstract
A method for evaluating bonding properties of a metallic pipe, the method comprises steps of measuring, in advance of a pipe expansion operation, at least one selected from a degree of shape discontinuity, a degree of defect at a bonding portion, and a degree of change in crystal structure, and comparing a measurement value with a predetermined threshold value to evaluate suitability of the bonding properties for applying pipe expansion.
Claims17
A method for evaluating bonding properties of a metallic pipe comprising:
- a first measurement step of measuring an echo height of an ultrasonic wave reflected back from an edge of a bonding interface where two pipe members are bonded together by diffusion bonding upon letting in an ultrasonic wave toward a first side of the bonding interface;
- a second measurement step of measuring an echo height of an ultrasonic wave reflected back from said bonding interface upon letting in the ultrasonic wave toward a second side of said bonding interface;
- a step fault determination step of determining whether or not there is a step fault present at said bonding interface based on a difference between the echo height measured in the first measurement step and the echo height measured in the second measurement step;
- and
- a defect determination step of determining whether or not there is a defect present at said bonding interface based on minimum values of the echo height measured in the first measurement step and the echo height measured in the second measured step.
2 more elements
A method for evaluating bonding properties of a metallic pipe comprising:
- arranging an ultrasonic probe around an outer circumferential surface of a first pipe member of the metallic pipe being bonded together by diffusion bonding, and measuring reciprocating time, by said ultrasonic probe, for an ultrasonic wave incident perpendicularly toward the outer circumferential surface of said pipe member to reflect back its echo therefrom;
- arranging an ultrasonic probe around an outer circumferential surface of a second pipe member of the metallic pipe, and measuring reciprocating time, by the ultrasonic probe, for an ultrasonic wave incident perpendicularly in the same direction as that of the first pipe member to the outer circumferential surface of said second pipe member to reflect back its echo therefrom;
- and
- calculating a size of a step fault produced at a bonding portion along the outer circumferential surface based on the reciprocating time of the outer reflected echo measured in said measurements;
- wherein said size of the step fault at the bonding portion along the outer circumferential surface LS is given by an expression,
- LS=CW×(tS2−tS1)/2,
- where
- CW:
- a propagation velocity with which the ultrasonic wave travels through a coupling medium intervening between said ultrasonic probe and the outer circumferential surface,
- tS1:
- the reciprocating time of the outer reflected echo of the first pipe member of the metallic pipe, and
- tS2:
- the reciprocating time of the outer reflected echo of the second pipe member of the metallic pipe.
10 more elements
A method for evaluating bonding properties of a metallic pipe, the method comprising steps of:
- measuring reciprocating time for an ultrasonic wave incident vertically to an outer circumferential surface of a first pipe member of the metallic pipe being bonded together by diffusion bonding to reflect back its echo from the outer circumferential surface and from an inner circumferential surface of said first pipe member of the metallic pipe;
- measuring reciprocating time for an ultrasonic wave incident vertically to an outer circumferential surface of a second member of said metallic pipe to reflect back its echo from the outer circumferential surface and from an inner circumferential surface of said second pipe member of the metallic pipe;
- and
- calculating a size of a step fault produced along the inner circumferential surface of a bonding portion from the reciprocating time of the outer reflected echo and the inner reflected echo measured in said measurements.
1 more element
A method for evaluating bonding properties of a metallic pipe, the method comprising steps of:
- measuring, in advance of a pipe expansion operation, at least one selected from a degree of shape discontinuity, a degree of defect at a bonding portion, and a degree of change in crystal structure, and comparing a measurement value with a predetermined threshold value to evaluate suitability of the bonding properties for applying pipe expansion.
Dependencies are inferred from the claim text.